ANNOTATED BIBLIOGRAPHY OF 40 BIRDS IN THE CALIFORNIA DESERT •nt Center #<]sr3 ANNOTATED BIBLIOGRAPHY OF 40 BIRDS IN THE CALIFORNIA DESERT by Ralph W. Schreiber, PH.D. Curator, Ornithology- Los Angeles County Museum of Natural History 900 Exposition Boulevard Los Angeles, California 90007 Lib for Bureau of Land Management Desert Plan Staff 1695 Spruce Street Riverside, California 92507 Completed December 1978 Contract CA-060-CT8-000045 ANNOTATED BIBLIOGRAPHY OF 40 BIRDS IN THE CALIFORNIA DESERT: 1. BLACK-HEADED GROSBEAK (Pheucticus melanocephalus) 2. CACTUS WREN ( Campy lorhynchus brunneicapillus couesi) 3. CALIFORNIA THRASHER (Toxostoma redivivum) 4. COMMON NIGHTHAWK (Chordeiles minor) 5. DOWNY WOODPECKER (Pico ides pubescens turati) 6. FOX SPARROW (Passerella iliaca) 7. GRAY FLYCATCHER (Empidonax wrightii) 8. GREAT HORNED OWL (Bubo virginianus) 9. GREEN-TAILED TOWHEE (Pipilo chlorurus) 10. HAIRY WOODPECKER (Picoides villosus leucothorectic) 11. HOUSE FINCH (Carpodacus mexicanus) 12. LADDER-BACKED WOODPECKER (Picoides scalaris cactophilus) 13. LAWRENCE'S GOLDFINCH (Carduelis lawrencei 14. LESSER GOLDFINCH (Carduelis psaltria) 15. LONG-BILLED MARSH WREN (Cistothorus palustris) 16. LONG-EARED OWL (Asio otus) 17. MOUNTAIN BLUEBIRD (Sialia currucoides) 18. MOUNTAIN CHICKADEE (Parus gambeli) 19. NORTHERN BROAD- TAILED HUMMINGBIRD (Selasphorus platvcercus - S.p. platycercus) 20. NORTHERN GRAY-HEADED JUNCO (Junco c. caniceps) 21. NORTHERN ORIOLE (Icterus galbula) 22. PINON JAY (Gymnorhinus cyanocephalus) 23. PLAIN TITMOUSE (Parus inornatus) 24. POOR WILL (Phalaenoptilus nuttallii) 25. RED- TAILED HAWK (Buteo jamaicensis) 26. RED-WINGED BLACKBIRD (Agelaius phoeniceus) 27. RUBY- CROWNED KNINGLET (Regulus calendula) 28. RUFOUS- SIDED TOWHEE (Pipilo erythrophthalmus) 29. SAGE THRASHER (Oreoscoptes montanus) 30. SOLITARY VIREO (Vireo solitarius cassinii) 31. SONG SPARROW (Melospiza melodia) 32. TURKEY VULTURE (Cathartes aura) 33. VIOLET- GREEN SWALLOW (Tachycineta thalassina) 54. WESTERN BLUEBIRD (Sialia mexicana) 35. WESTERN FLYCATCHER (Empidonax d. difficulis) 36. WESTERN KINGBIRD (Tyrannus verticalis) 37. WESTERN MEADOWLARK (Sturnella neglecta) 38. WESTERN WHITE -THROATED SWIFT (Aeronautes saxatalis - A. s. saxatalis) 39. WILSON'S WARBLER (Wilsonia pus ilia) 40. YELLOW- RUMPED WARBLER (Dendroica coronata) # BLACK- HEADED GROSBEAK Pheucticus melanocephalus I TAXONOMY A. Type description AOU (1957) P. m. melanocephalus : Guiraca melanocephalus Swainson, PTiil. Mag. , n. sTj I~7 no"! 6, June 1827, p. 538. (Table land. Temiscaltipec = Temascal tepee, Mexico.) P. m. maculatus : Fringilla maculata Audubon, Birds Amer. Tfolio), vol. 4, 1837, pi. 373, Figs. 2-4. (Columbia River [, Oregon].) B. Current systematic treatments Paynter (1970), recognizes four species in the genus Pheucticus; two subspecies of melanocephalus , both of which occur in California. Order: Passerif ormes ; Family: Emberizidae ( Cardinal inae ) . C. Synonomies of scientific nomenclature P. m. melanocephalus : Dawson (1923), Hedymeles melanocephalus melanocephalus. Ridgway (1901), zamelodia melanocephala. ) Grinnell and Miller (1944) , Habia melanocephala. P. m. maculatus : Dawson (1923), Hedymeles melanocephalus capital is. Grinnell and Miller (1944) , Coccoborus melano- cephalus; Pitylus melanocephalus ; Guiraca melanocephala; Goniaphea melanocephala; Zamelodia melanocephala micro- rhyncha; Habia melanocephala; Z. m. maculata. D. Synonomies of vernacular nomenclature II DESCRIPTION A. External morphology of adults Dawson (1923), H. m. melanocephalus "Adult male in summer: Head above and on sides, and narrowly across chin, glossy black, area of black occasionally invaded by a supra- auricular stripe of orange-tawny; a cervical ring, sides of neck, throat, breast, and sides, rump, and interrupted stripes connecting rump and cervix, orange- tawny. . . , paling on flanks posteriorly to buckthorn brown; a touch or wash of the lighter shade also on crissum, which is otherwise white; abdomen narrowly white, middle of breast, axillars, and lining of wings pure lemon-yellow; remaining upperparts black, inter- rupted, as aforesaid, on back by tawny, and on wings by > Pheucticus melanocephalus (con't.) broad white tips of median coverts, narrower white tips of greater coverts and secondaries; basal portion of remiges, nearly half on primaries, white: the 6th, 7th and 8th primaries (reckoned from within) sharply edged with white on the distal portion; rectrices black, the two outer pairs broadly tipped and the 3rd pair touched with white on inner web; tibiae black tipped with white. Bill dark horn-color, lightening below; feet dark brown. Adult female: Very different; pattern of male preserved only in yellow of axillars and wing- linings, with touches of yellow on breast; in general, above blackish, streaked with white; below fulvous, streaked sharply and narrowly with blackish; pileum blackish, separated by a coronal stripe of white sharply flecked by black; lores and superciliary broadly white; back black, broadly edged with whitish or fulvous; white spotting of wings much restricted; the spots on tail lacking; underparts chiefly whitish, clearest on chin, throat (or else on sides of throat only), and abdomen; elsewhere more or less suffused with pale ochraceous, most intensely on breast, and sharply streaked with dusky." P. melanocephalus maculatus: 'Similar to H. (P.) m. melano- cephalus, but bill averages smaller; black of crown more liable to invasion of tawny from behind, especially in post- ocular stripe, and occasionally developing a median crown- stripe." Ridgway (1901), detailed description of adult males and females in summer and winter, including plumage, soft parts, and measurements. Peterson (1961) "Male: Rusty wings, and large pale bill... In flight shows black and white wing and tail pattern, cinnamon rump. Female: Largely brown; streaked. Breast washed with light brown (usually) and lightly streaked on sides." B. External morphology of subadult age classes Dawson (1923), "resemble the adult female, but the ochraceous element is stronger both above and below, and the lesser wing-coverts are extensively edged with yellow." Ridgway (1901), detailed description of young, including plumage and soft parts. C. Distinguishing characteristics Interspecific - Peterson (1961), "Female Rose-breasted Grosbeak (East) usually has a whiter, more streaked breast." Intraspecific - Dawson (1923), "There is no doubt that coastal specimens exhibit this ochraceous invasion of the cephalic areas more frequently than do Rocky Mountain specimens; but the latter do show individual examples of the same tendency, and the grounds of separation are probably not valid." • • 0 Pheucticus melanocephalus (con't.) I GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) Pheucticus melanocephalus in general: "Southern British Columbia, southern Alberta, southern Saskatchewan, and central Nebraska south to northern Baja California, Guerrero and Oaxaca. Fossil, in the late Pleistocene of California." P. m. melanocephalus : "Breeds from southeastern British Columbia (Okanagan Landing, Creston) , northwestern Montana (Flathead Lake), southeastern Alberta (Walsh), southwestern Saskatchewan (Maple Creek), northeastern Montana (Glasgow), and northwestern North Dakota (Charleson) south through eastern Washington and eastern Oregon to extreme eastern California (White Mountains, Clark Mountain), central and southeastern Arizona (Prescott, Huachuca Mountains) and the Mexican Plateau to Guerrero (Amojileca) and Oaxaca (Cerro San Felipe); east to central Nebraska (Greeley) and central Kansas (east to Cloud and Harvey counties), western Oklahoma, western Texas (Midland County), and Tamaulipas (La Joya de Sal as)." P. m. maculatus: "Breeds from southwestern British Columbia XQuinsam Lake, Caquitlam) south along the Pacific coast to northern Baja California (Sierra San Pedro Martir) ; east in California to Owens Valley and the San Bernardino Moun- tains." Dawson (1923), P. melanocephalus : "Western North America from the plateau of Mexico north, in summer, to eastern Kansas, southeastern Dakota, Montana, and British Columbia; breeds throughout its range." B. California distribution of the species P. melanocephalus melanocephalus: Dawson (1923), "Restricted to the portion lying east of the Sierra-Cascade Mountain system... At least the Colorado River valley during migra- tions; presumably the breeding bird in mountain ranges east of the Sierras." P. melanocephalus maculatus : Dawson (1923), "The Pacific (!oast district of western North America, broadly; probably includes eastern slopes of Sierra-Cascade system." C. California desert distribution Grinnell and Miller (1944), P. m. melanocephalus : "As breeding, mountains of Mono and Inyo counties east of Owens valley, extending south to eastern San Bernardino County. Pheucticus melanocephalus (con't.) In migration, Colorado River valley, Colorado and Mohave deserts west to Twentynine Palms, and valleys of eastern Inyo County . " P. m. maculatus : "Breeds throughout State west of south- east ern- Heserts and Owens Valley, with exception, apparently, of coastal islands; in desert mountains of Mono and Inyo counties replaced by H. (P.) m. melanocephalus . In migration appears additionally on islands and in desert areas." D. Seasonal variations in distribution P. m. melanocephalus - AOU (1957), "Winters from southern Sonora (Alamos), southern Chihuahua (Chihuahua), Nuevo Leon (Mesa del Chipinque), and Louisiana (Shreveport, Monroe) south to Guerrero and Oaxaca." P. m. maculatus - AOU (1957), "Winters from southern Baja California (La Paz), southern Sonora (Tesia), and southwestern Chihuahua south to Oaxaca (Mitla)." Dawson (1923), P. m. maculatus : "casual in winter in the San Diegan district." Grinnell and Miller (1944), P. m. melano- cephalus: "a common migrant on eastern deserts, appearing in spring in mid-April and continuing through May." P. m. maculatus: "Summer resident from early April to early September. Migrations occur normally in late March and April, and in late August and September; spring arrivel in higher mountains and in northern California two to four weeks later than in other sections, and migration continues through May east of Sierran axis." !V HABITAT A. Biotopic affinities Grinnell and Miller (1944), P. m. melanocephalus : "Life zone occupied for nesting, Upper Sonoran and Transition. . .Pinon woodland primarily, but also mountain mahogany and, where available, firs and rose and willow thickets, the latter apparently preferred." P. m. maculatus: "Life zones in summer, Lower Sonoran, Upper SonorarTj and Transition. . .Riparian woodland, oak woodland with associated shrubs, and open coniferous forests of Transition and Upper Sonoran zones, especially where inter- mixed with deciduous oaks. The range in habitat is thus great and includes plant growths so diverse in type as willows, black oaks, fruit orchards, and juniper trees. Most favored is the willow-cottonwood association." Weston (1947), "may ordinarily be found in the woodland or in riparian * Pheucticus melanocephalus (con't.) I groves and thickets. . .Most often found in the open woods... Along edges or transitions between grassland and woodland or chaparral, grosbeaks are also common; but they enter chaparral and grassland only infrequently and then only in search of food." Small (1974), "for breeding, open coni- ferous montane forest, riparian woodland, oak woodland in foothills and lower mountain slopes; otherwise, woodland patches and groves in lowlands." Miller (1951), Upper and Lower Sonoran and Transition life zones. Austin (1968), "in thickets of bushes, small trees, or willows which grow along streams, around the edges of swamps, ponds, or damp places, as well as on the edges of open woods, where the sunlight filters down through the foliage, but almost always not far from water or low ground." B. Altitudinal range Dawson (1923), "Ranging from 5000 feet up to 8500 feet," for P. m^ melanocephalus . "Range from near sea level at least up to 7500 feet in Warner Mountains of Modoc County and in southern Sierra Nevada," for P. m. maculatus. C. Home range size D. Territory requirements Perch sites - Gander (1929), "seen perched on an electric light wire." Weston (1947), "for singing perches, gros- beaks appear to require fair visibility. . .best afforded by open woods." Courtship and mating sites - Weston (1947), "Courtship and selection of mates occurs after the grosbeaks arrive on their breeding grounds." Nest sites - Dawson (1923), "Externally a bulky... airy assemblage of interlaced twigs or dishevelled weed- stems, or sometimes a generous mass of leaf-bearing twigs plucked green. . .Placed at moderate heights in the larger bushes, saplings, or small trees, chiefly those of the riparian association. Weston (1947), "Nesting occurs most commonly in streamside bushes and trees and in the live oaks of open woods." Includes descriptions of six different nest sites in Strawberry Canyon, Berkeley, California. In general: "in deciduous bushes and trees bordering streams. . .Also in bushes or trees away from stream courses in gardens, dense brushland, closed woods and parklands. . .Placed in trees and bushes, usually at a height of six to twelve feet above the ground." Pheucticus melanocephalus (con't.) E. Special habitat requirements Grinnell and Miller (1944), "Perhaps an important factor is local diversity of plant growth and extensive 'edge' conditions", for P. m. maculatus. F. Seasonal changes in habitat requirements V FOOD A. Food preferences Dawson (1923), "fruit in season, especially cherries and f igs .. .codling moth, cankerworms, flower-beetles. .. scale insects." Grinnell and Miller (1944), "food is varied and the species may require several kinds of supply in the nest- ing area. Insects and buds are sought in the foliage of broad-leafed trees especially, and berries and other fruits are taken in large quantity." Weston (1947), "Insects and other animal matter eaten by grosbeaks amount to more than the bulk of the vegetable food and should probably be regarded as their main food." Fisk and Steen (1976), re- port this species feeding on nectar from feeders in Arizona. Ivor (1943), reported this species feeding upon ants (in captivity) . B. Foraging areas Weston (1947), "The extensive peripheral foliage character- istic of open woods is advantageous to grosbeaks in foraging for food. . .Forage predominantly in trees... May occasionally be seen flying out in midair in pursuit of insects. . .May also frequent the ground in search of food." C. Foraging strategies Gander (1929), "from this perch it would make short fly- catcher-like flights, presumably after insects." D. Feeding phenology Weston (1947) "A seasonal shift in food, probably due mainly to change in availability. For several weeks after their arrival on their summering grounds, grosbeaks fed mainly on such soft succulent vegetable matter as leaf buds, flowers and flower buds, as well as on early forming fruits. Worm- like larvae of various lepidopterous insects were also con- spicuous in the diet at this time. As the weeks passed, a slow change was discernible. With the maturing of other fruits, the grosbeaks resorted to them in turn and fruit then became predominant in the diet. Early in the summer, • Pheucticus melanocephalus (con't.) >with the disappearance of many of the fruits, the vegetable diet shifted to one consisting mainly of seeds, found in foraging about on the ground and in the bushes. Except for the seasonal changes in the forms of lepidopterous in- sects and the accompanying change in the diet, I noticed no appreciable shift in the animal diet of the adult birds." E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Weston (1947), "The males arrive singly rather than in flocks and are solitary for the few days preceding arrival of females. They begin singing upon arrival. . .Males appeared to be spaced, but I saw no conflicts between them until after the arrival of females. . .Active competition among males appeared to occur only in the presence of females ...Practically all local species of birds except predators and other grosbeaks are tolerated at the nest." Kroodsma (1974), comparison of species recognition behavior, with regard to territoriality, with that of the Rose-breasted ft Grosbeak. C. Courtship and mating behavior Weston (1947), "lone females arrived six days after the males, and the grosbeaks engaged actively in courtship soon after. Two or even three males would be singing and flying about in the vicinity of one female, occasionally chasing her... The only type of display seen was a nuptual flight. Loud songs were uttered from some exposed perch near a female and then the male would suddenly fly up and out, performing a song- flight in the air above her. Flying forth on a horizontal course, the male would circle out from the summit of a tree, with the wings and tail spread, uttering an almost continuous song. In the air for eight to ten seconds, he would then fly back, usually to the perch just vacated. . .During the early part of the season the paired birds forage together, and at this time the male is distinctly aggressive." D. Nesting phenology Dawson (1923), "May- June; one brood." Davis (1933), reports in Butte. Co., California, the first date as 1 May; the last date as 31 May; the average date as 15 May. Weston (1947), ^ "Construction of the nest takes from three to four days... Building of the nest is done by the female." Pheucticus melanocephalus ( c on * t . ) E. Length of incubation period Mr Weston (1947) "Continuous incubation normally begins with the laying of the next to last egg. Both sexes incubate ...Lasts 12 days; all eggs hatch within 24 hours." F. Length of nestling period Weston (1947), reports twelve days. G. Growth rates H. Post-breeding behavior Weston (1947), "In the latter part of the season the young follow the females, the males having left soon after nesting is over. I have seen females feeding well grown young as late as the early part of August." I POPULATION PARAMETERS A. Clutch size Dawson (1923), reports three or four. Weston (1947) reports from three to four in six nests, although has records of ^^ sets of two and five eggs. ^^ B. Fledging success C. Mortality rates per age class D. Longevity Kennard (1975), reports record age of 6 years in 1938 when trapped and released. Banded after hatching year in 1933. Sex unknown. E. Seasonal abundance F. Habitat density figures Gaines (1974), reported 123 and 158 territorial males per square kilometer of clumped cottonwood and willow woodland in Butte County, California; seventy-five territorial males per square kilometer on floodplain gravel bar in Glenn and Butte Counties, California, 1973; 130 per square kilometer in clumped cottonwood and willow woodland, Glenn and Butte Counties, California. 9 Pheucticus melanocephalus (con't.) I INTERSPECIFIC INTERACTIONS A. Predation Stoner (1933), reports remains of this species in full spring (male) plumage in nesting cavity of Western Burrowing Owls near Benicia, California. Allen (1930), reported observa- tions of Gray Squirrel examining nest of this species con- taining two eggs. The squirrel was driven off by the adult birds. B. Competition Weston (1947), "Wren-tits (Chamaea fasciata) were seen picking at one occupied nest~j Bush-tits (Psaltriparus minimus ) were seen foraging on a nest, a Pileolated Warbler (Wilsonia pusilla) was seen standing on the rim of another nest, and none caused any apparent alarm on the part of the grosbeaks." C. Parasitism Payne (1976), reports this species as a host of Brown- headed Cowbirds in California. jX STATUS A. Past population trends Grinnell and Miller (1944), P. m. melanocephalus : "Summer resident of restricted area in central eastern section of State; common." P. m. maculatus: "Common generally; in some areas abundant." B. Present population status Small (1974), "transient and summer visitor." C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status 10 Pheucticus melanocephalus (con't.) XI LITERATURE CITED Allen, W. I. 1930. Do Gray Squirrels destroy eggs or young birds? Condor 32:262. American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Austin, 0. L. , Jr. (Ed.) 1968. Life histories of North Amer- ican cardinals, grosbeaks, buntings, townees, finches, sparrows, and allies. Part 1. Bull. U.S. Nat. Mus. No. 237. Davis, W. B. 1933. The span of the nesting season of birds in Butte County, California, in relation to their food. Condor 35:151-154. Dawson, W. L. 1923. The birds of California. South Moulton Co. , San Francisco. Fisk, L. H. and D. A. Steen. 1976. Additional exploiters of nectar. Condor 78:269-271. Gaines, D. 1974. A new look at the nesting riparian avifauna of the Sacramento Valley, California. Western Birds 5(3): 61-80. Gander, F. G. 1929. Notes on the food and feeding habits of certain birds. Condor 31:250-251. Grinnell, J. and A. H. Miller, 1944. The distribution of the birds of California. Pacific Coast Avifauna, No. 27. Ivor, H. R. 1943. Further studies of anting by birds. Auk 60:51-55. Kennard, J. H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. Kroodsma, R. L. 1974. Species-recognition behavior of terri- torial male Red-breasted and Black-headed Grosbeaks (Pheucticus). Auk 91:54-64. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. Vol. 50, No. 6. Payne, R. B. 1976. The clutch size and number of eggs of Brown-headed Cowbirds: Effects of latitude and breeding season. Condor 78:337-342. * m 11 Pheucticus melanocephalus (con't.) Peters, J. L. 1970. Checklist of birds of the world. Vol. 13. (R. A. Paynter, Jr., ed. ) Mus. Comp. Zool., Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co. , Boston. Ridgway, R. 1901. The birds of North and Middle America. Part 1. Bull. U.S. Nat. Mus. No. 50. Small, A. 1974. The birds of California. Macmillan Co. , New York. Stoner, E. A. 1933. Some subsistence items of Western Burrow- ing Owls. Condor 35:204. Weston, H. G. , Jr. 1947. Breeding behavior of the Black- headed Grosbeak. Condor 49:54-73. ^ CACTUS WREN Campylorhynchus brunneicapillus couesi TAXONOMY A. Type description AOU (1957), Campylorhynchus couesi Sharp, Cat. Birds Brit. Mus., 6, 1881, pp. 186 (in key), 196. (Larido [=Laredo] , Texas) B. Current systematic treatments Selander (1964) discussion of relationships within the genus Campylorhynchus. Paynter and Vaurie (1960) recognize ten species in the genus, seven subspecies of brunneicapillus. Pas seri formes: Troglodytidae. Ridgway (1904), discussion of morphological characteristics and geographic distribution in relation to systematic treatment. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Heleodytes brunneicapillus couesi; Campylorhynchus couesi; H. b. bryanti; H. b. anthonyi; H. b. brunneicapillus ; H. af finis . D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Brown-headed Wren; California Cactus Wren; Brown- capped Cactus Wren; Bryant Cactus Wren. II DESCRIPTION A. External morphology of adults Dawson (1923) "Pileum and nape warm brown... the former with dusky mesial streaks; back and scapulars, broadly, pale grayish brown, highly varied by mesial white in streaks and stripes, and submesial dusky; f light-feathers. . .dusky, spotted with white and brownish on outer webs, and broadly with white on inner webs. .., tail. . .blackish, finely and irregularly barred with pale grayish brown; concealed webs of lateral rectrices chiefly black, the outermost pair black and white barred throughout; the remaining pairs with at least a subterminal band of white; a prominent superciliary, continued to bill, white; post-ocular area clear brown; cheeks mingled brown and white; underparts basally white, immaculate on chin and upper throat, tinged with pale 9 Campy lorhynchus brunneicapillus (con't.) cinnamon on belly and crissum; the sides of throat, lower throat, and chest heavily spotted with black. . . ; breast, sides of belly, sides, and crissum sharply and rather finely spotted with black." Ridgway (1904), detailed description of adults, including plumage, soft parts, and measurements. B. External morphology of subadult age classes Dawson (1923), "more sparingly spotted below, especially on chest." Ridgway (1904), "Essentially like adults, but paler markings of upper parts less sharply defined, pale brownish buff or dull brownish white; pileum and hindneck duller brown; outer webs of primaries and secondaries spot- ted with pinkish buff instead of white, and blackish spots on throat and chest much smaller, the former almost immaculate. " C. Distinguishing characteristics Interspecific - Dawson (1923), "largest of American wrens; highly varied (white- striped) upperparts and heavily black- spotted underparts." Selander (1964) examination of the genus Campy lorhynchus with a comparison of brunniecapillus with other members of the genus. Intraspecific - EII GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), "Southern California, southern Nevada, south- western Utah, western and south-central Arizona, southern New Mexico, and central Texas south to southern Baja Calif- ornia, Michoacan, and State of Mexico." C. b. couesi: "Resident from southern California (Santa Paula, San Fernando, Mohave, Little Owens Lake, Argus Mountains), southern Nevada (Charleston, Sheep and Muddy Mountains), southwestern Utah (Beaver Dam Mountains, Toquerville) , south-central Arizona (Salt River Valley, Globe, Dos Cabezas) , southern New Mexico (Silver City, San Marcial, Eagle, Tularosa, Carlsbad), and central and central Texas (Pecos, San Angelo, Lomita, San Antonio Range, Brownsville) south to northern Baja Calif- ornia (Ensenada, Tijuana, El Valle de la Trinidad, eastern base of the Sierra San Pedro Martir) , northern Sonora (Puerto Libertad, Pesquiero, 12 miles west of Magdalena) , central Chihuahua (Chihuahua) central Coahuila (Monclova) , Nuevo Leon (Galeana), and northern Tamaulipas (Nuevo Laredo, Matamoros) . f f Campy lorhynchus brunniecapillus ( con ' t . ) B. California distribution of the species Grinnell and Miller (1944), "Southeastern desert area... the Colorado and Mohave deserts, north from Mexican boundary to Inyo and Kern counties; and also most arid parts of westward drainage slope from San Diego County northwest to Ventura County." C. California desert distribution Dawson (1923), "Lower Sonoran deserts of southern California . . .north to southern end of Owens Valley; also locally resi- dent in the San Diego district north to Simi." Small (1974), "Southeastern deserts (Colorado, Mojave, Sonoran) and suitable arid habitats north coastal to Ventura County." Miller (1951), Colorado Desert, Mojave Desert, San Diego, Upper Kern Basin. D. Seasonal variations in distributions Anderson and Anderson (1973), "territory is used for mating, nesting, and as a feeding ground for the young, and it is also retained as a roosting area for the remainder of the year..., Remained. .. throughout the winter with extremely slight shifts in territory." V HABITAT A. Biotopic affinities Grinnell and Miller (1944), "Sharply defined as arid terrain grown to thickets, patches or tracts of cactus of the larger, branching types, or of stiff- twigged, thorny brush or small trees. . .provide safe refuge. .. sites for nests that are inaccessible to terrestrial maranders. .. required food, insects, spiders and, in season, fruits. Besides cholla and tuna cactuses, plants that are used... are yuccas of the arborescent kinds, catclaw, mesquite, screw-bean, iron- wood and palo verde." Small (1974), "deserts with suitable cacti, yuccas, and shrubs for nesting, arid coastal hill- sides, arid interior valleys." Miller (1951), Lower Sonoran Life Zone. B. Altitudinal range Grinnell and Miller (1944), "from 180 feet below sea level, as around Sal ton Sea, Riverside, and Imperial counties, up to 5800 feet, in Argus Mountains, Inyo County." Campy lorhynchus brunneicapillus (con't.) C. Home range size Anderson and Anderson (19 73) "estimate the average size of a territory at 4.75 acres (1.9 ha), the minimum 2.9 acres (1.16 ha), and the maximum 6.9 acres (2.76 ha)," Santa Rita Experimental Range, Arizona. D. Territory requirements Perch sites - Anderson and Anderson (1957), "The male sang from most of the available perches in his territory, such as creosote bushes, chollas , mesquites, roof-tops, radio antennas, windmills, and electric power poles and wires." Courtship and mating sites Anderson and Anderson (19 54), "territory is used for mating, nesting, and feeding ground for the young, and it is also retained as a roosting area for the remainder of the year. . . territorialism probably assisted in maintaining the pair- band." Nest sites - Dawson (1923), "a cylindrical mass of dried grasses, heavily lined with feathers; placed horizontally, with entrance at one end, and well-shaded above; in top of cholla cactus, yucca, or at base of sahuaro branch, or, more rarely, in mesquite, or other desert shrub." Anderson and Anderson (1963), "The use of a covered nest that obstructs the direct rays of the sun is of considerable advantage... If the roof ... completely shades the nest cavity, and if the walls are sufficiently porous to permit air circulation, the temperature of the inside of the nest approached the standard shade temperatures." Anderson and Anderson (19 57) "Cholla cacti were used almost exclusively ... Nest heights... were limited to height of the chollas. Average height... was from four to five feet... the nest, when placed in a dense jumping cholla, is almost always at the outer surface of the crown, the entrance pointing outward from the cholla." Ricklefs and Hainsworth (1969), detailed discussion of en- vironmental temperatures of nesting Cactus Wrens. Austin (1974), consideration of nesting success in relation to nest orientation. E. Special habitat requirements Dawson (1923), "local range nearly coincident with that of Opuntia cacti. ..and the tree yuccas." t 0 Campy lorhynchus brunniecapillus (con't.) F. Seasonal changes in habitat requirements Anderson and Anderson (1963) "In the normal desert habitat, pools of water are seldom available for any useful length of time. . . ; Provided a steady supply of water in a bird bath saucer. . . ; Drinking by adult wrens from this pool became noticeable in September, increasing to a high in December and January. . . ; Evidently the insect food obtain- able in the winter months does not have a sufficiently high water content to satisfy the needs of the wrens... As the days grew warmer the insect population increased, and the wrens seldom came to drink. V FOOD A. Food preferences Woods (1932), "fruit of the cultivated 'spineless' cactus ...sweet corn." Anderson and Anderson (1973) "white flowers of the saguaros. . .The birds probed their bills deep into the long corollas, apparently to obtain the nectar. . .Also cap- tured any insects trapped in it. . . ; beetles and Hymenoptera ... grasshoppers. . .bugs. .. caterpillars. .. fruit pulp and weed seeds. " B. Foraging areas Grinnell and Miller (1944), "Foraging, chiefly on the ground, extends but a few rods radially from £nest sitesj ." Anderson and Anderson (1973), "Foraged on the ground in autumn and winter, picking up food from the surface and from low vege- tation within reach. . .By the time nesting was well under way, deciduous perennial vegetation leafed out. The wrens spent less time now on the ground, and by midsummer they foraged frequently in the palo verde and mesquite trees, the cholla cacti and saguaros." C. Foraging strategies Anderson and Anderson (1963) "obtained relief from midday summer sun by seeking the shade of bushes and trees. In their search for food on the ground, they visited open spaces for only short periods of time or avoided them al- together." Bent (1948;, "approaches a leaf or other movable object, inserts its bill carefully under one side, and raises it up, meanwhile peering beneath it in readiness to seize any small creature thus revealed." Campylorhynchus brurmeicapillus (con't.) D. Feeding phenology ^^ Ricklefs and Hainsworth (1968a) "as temperatures throughout the environment become progressively hotter, birds select relatively cooler microhabitats by shifting their foraging location, and that after the minimum temperature reaches a critical level of stress, activity decreases. . .This change in behavior in the absence of changes in food availability suggests that heat stress, rather than insect activity, is the principle determinant of the behavior. . .During the time of greatest heat stress. . .must rely exclusively on water obtained from its food." Anderson and Anderson (1973) "pushed the smaller debris aside, or turned it over with their bills to facilitate their search for food. The)'' did not dig. " E. Energy requirements Ricklefs (1966) "The growth curves... are sigmoid in shape and thus the rate of growth, and hense the required input of energy, is highest during the middle of the growing period and tails off toward both ends. It is possible that while the growth rate is increasing and the parents are becoming increasingly taxed, the energy resources of the young are directed primarily to growth, and behavior is limited to begging and defecation." 4^ VI REPRODUCTION A. Age at first breeding Anderson and Anderson (1962), "New nests were started at the average age of 116.5 days [roosting nests]." B. Territorial behavior Anderson and Anderson (1963), "Once established, the adult wren remains in its chosen territory for life; it mates for life." Anderson and Anderson (1957), "Territorial intoler- ance began at least in January. By February. .. the area was usually cleared of other wrens. Females were most active in driving out other females by chasing and fighting. The male apparently kept out other males. Singing by the male increased as the territory was secured." C. Courtship and mating behavior Anderson and Anderson (1957), "Since the sexes are identical in coloration and size, sex discrimination must be by means of distinctive behavior. . .Females are probably attracted to males upon hearing the song. When they meet, there is a Campylorhynchus bnmneicapillus ( con ' t . ) threatening display by the male, including the spreading of his wings and tail, accompanied by a growling sound. A female also displays and then she crouches. . .Pair- forma- tion has not been observed." Anderson and Anderson (1960), "Courtship feeding by the male occurred three to four times a day [during incubation by the female"]." D. Nesting phenology Dawson (1923), "March, April- June, two broods." Anderson and Anderson (I960), "Incubation was performed entirely by the female. Partial incubation began the night after the first egg was laid; daytime incubation was irregular until the clutch was nearly complete. . .Hatching of eggs was spread over a period of two or three days. . .Nestlings are fed small fresh insects from the time they are hatched. Feeding by regurgitation was not observed. . .The first egg of the second brood was laid in from 0 to 13 days after the fledging of the first brood." E. Length of incubation period Anderson and Anderson (1960), sixteen days. Asynchronous hatching. Hensley (1959) "lasted 17 days in two nests." F. Length of nestling period Anderson and Anderson (1960) "average time which the nest- lings spent in the nest was 20.9 days... range was from 19 to 23 days." Ricklefs and Hainsworth (1968b), "The develop- ment of homeothermy. . . was investigated over the range of ambient temperatures prevailing in their habitat during the nesting season. Thermogenic responses develop later and more slowly than in other species that have shorter nestling periods." Hensley (1959), for six of the nests ranged from 17 to 20 days." G. Growth rates Anderson and Anderson (1962) "Young. . .attained the average adult weight of 38.9 grams at about the age of 38 days." Anderson and Anderson (1961). Growth and development (morphological and behavioral) monitored daily from age one day to age 18 days, including weights and measurements. "Lowest weight on day of hatching was 2.6 grams ... Growth of wings was slow up to the 5th day, at which time, the sheaths pierced through the skin. Then the rate increased with the increments to sheath length until the 13th day, after which the rate dropped again. The tail feathers maintained a steady rate of increase." Ricklefs (1975), detailed pre- sentation of analyses of growth including age and body weight growth; increase in linear measurements of the body, Campy lorhyrichus brunneicapillus (con't.) limbs and feathers; increase in body constituents with resulting changes in the percentage composition of the body and its caloric density; and increase in weight of major body components and organs and their relative growth rates with respect to the body as a whole. Ricklefs (1966) comparison of behavioral development of Cactus Wren and Curve-billed Thrasher nestlings. H. Post-breeding behavior Anderson and Anderson (1962), "The adult shared the feeding duties for a short while. . .When the female began incubating her next clutch of eggs, the male took care of the brood. Exploratory pecking occurred as soon as the wrens were fledged. Self- feeding began at about the age of 35 days. . . They became independent of their parents at the age of 50 days. . .Adults broke up the family bond by gradually ignoring the begging fledglings. . .Two instances of juvenile wrens feeding fledglings of a latter brood were observed." Anderson and Anderson (1957) , "required a covered roosting nest in all months of the year. . .Usually by the end of the breeding season some of the old nests had deteriorated; others had been relinquished to the immature birds. The adults selected new sites and built again." VII POPULATION PARAMETERS A. Clutch size Dawson (1923), "4 or 5, rarely 6." Anderson and Anderson (1960), "Eggs were laid at a rate of one a day. . .average eggs per clutch was 3.41. . .Maximum number of broods raised was three." B. Fledging success Anderson and Anderson (1963), "fledged 82 young from 27 successful broods, with an average of 6.83 per year." Austin (1974), "orientation of the nest entrance appears to have an effect on its success, apparently acting at the nestling stage." Includes figures for hatching, fledging, nestling, and nest success in relation to nest-entrance orientation. Ricklefs (1968), of 39 young fledged from 14 nests, only 5 were lost after three to forty days after fledging. C. Mortality rates per age class Anderson and Anderson (1973) "evidently the Cactus Wren's most dangerous period is not in the egg or as a nestling. It occurs after fledging." 0 Campy lorhynchus brunneicapillus ( con ' t . ) D. Longevity Anderson and Anderson (1973), "The average age of seven males in the Kleindale Road area was 737 days; 16 females averaged 493 days. Five... in the Saguaro National Monu- ment area lived for at least 4 years." E. Seasonal abundance Anderson and Anderson (1957), "never observed in such large numbers [flocks of 6 to 30 or more as reported by Howell (1916). Hensley (1959), twenty- two active nests found in the intermountain desert plains in Organ Pipe Cactus National Monument, Arizona. Anderson and Anderson (1973), "The population peak, which was attained in late summer, was produced entirely by the addition of immature birds that had been raised in the vicinity. . .The population gradually decreased as the immature birds left or vanished, reaching its lowest point in winter." F. Habitat density figures Dawson (1923), "tend to colonize in loose association of from ten to twenty pairs." Anderson and Anderson (1973) Santa Rita Experimental Range: "Their population density from 1953 to 1956, excluding the extralimital territories 0 . .., varied from 8.3 to 23.3 pairs per 100 acres (40.5 ha). The average is 13.3 pairs Saguaro National Monument: 18 to 38 pairs per 100 acres. VIII INTERSPECIFIC INTERACTIONS A. Predation Anderson and Anderson (1963), "The most dangerous predator was the house cat. Cats, Roadrunners, and snakes were 'mobbed' and followed by the wrens until they left. Shrikes, although apparently innocuous, were harassed whenever they appeared." Bond (1936), "At the nest site [Falco mexicanus] was found. .. fresh feathers (but no corresponding pellet) of a Northern Cactus Wren." Austin, Yensen, and Tomoff (1972), describe a number of observations of snakes preying upon nestlings (Gopher Snakes and Whipsnakes). B. Competition Anderson and Anderson (1963) "Although a direct competition for nesting sites in cholla cacti, the Inca Dove appeared to have little difficulty in maintaining its hold in the vicinity. . . ; While feeding on the ground, the Cactus Wren always gave way at the approach of Curved-billed Thrasher ...both vigorously defended their own breeding nests... 0 10 Campy lorhynchus bruimeicapillus (con't.) attack the fledgling thrashers that strayed into their vicinity. . .Most obvious evidence of conflict was the per- sistent destruction of the roosting nests... by the Curve- billed Thrashers. . .Recorded approximately 200 incidents of total or partial destruction. .. from 1932 to 1961... Thrashers did not attack breeding nests while they were in use. . .Never defended [roosting nests] against attack. . .Young [Cactus Wren and Thrasher] fledged sufficiently close to- gether to be in competition for food." Re: Passer domesticus, "observed no competition for cholla nesting sites. . . filled a niche within the Cactus Wren territory that was not used by the wrens." C. Parasitism Anderson and Anderson (1973) "Molothrus ater, observed occasionally in the area, did not parasitize any of the Cactus Wren. . .nests. " IX STATUS A. Past population trends Grinnell and Miller (1944) "Completely resident, .. .numbers sufficient only very locally such as to merit term 'common' or 'abundant.'' Range on coastal slope of southern Calif- ornia now much restricted as compared with condition in 1880 's and 1890' s, owing to- great reduction of requisite habitat, as also, perhaps, in part, to the attentions of egg collectors." B. Present population status Small (1974), "common resident." Anderson and Anderson (1973), "weak intraspecific intolerance permits more ter- ritorial 'compressibility' in years of surplus individuals. Their population density is greater, not only because their production is greater, but because the surviving surplus is allowed to crowd in to nest." C. Population limiting factors D. Environmental quality: adverse impacts Dawson (1923), "All proper desert areas west of San Gorgonio Pass are being threatened sharply by human invasion. . .The Cactus Wren has receded from many parts of the San Diego- Ventura section already." Anderson and Anderson (1973; "destruction of the Cactus Wren's habitat proceeds at an alarming rate in the vicinity of the every- expanding south- western desert cities." 11 t Campylorhynchus brunneicapillus ( con ' t . ) E. Potential for endangered status Anderson and Anderson (1963), "will probably be able to maintain themselves in limited numbers within the resi- dential sections of the rapidly expanding cities of our southwest. " 12 Campy lorhynchus brunneicapillus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Anderson, A. H. and A. Anderson. 1957. Life history of the cactus wren. Part I: Winter and pre-nesting behavior. Condor 59:274-296. Anderson, A. H. and A. Anderson. 1959. Life history of the cactus wren. Part II: The beginning of nesting. Condor 61:186-205. Anderson, A. H. and A. Anderson. 1960. Life history of the cactus wren. Part III: The nesting cycle. Condor 62:351- 369. Anderson, A. H. and A. Anderson. 1961. Life history of the cactus wren. Part IV: Development of nestlings. Condor 63:87-94. Anderson, A. H. and A. Anderson. 1962. Life history of the cactus wren. Part V: From fledging to independence. Condor 64:199-212. Anderson, A. H. and A. Anderson. 1963. Life history of the cactus wren. Part VI: Competition and Survival. Condor 65:29-43. Anderson, A. H. and A. Anderson. 1973. The cactus wren. U. of Arizona Press, Tucson. Austin, G. T. 1974. Nesting success of the Cactus Wren in relation to nest orientation. Condor 76:216-217. Austin, G. T. , E. Yensen and C. S. Tomoff . 1972. Snake pre- dation on Cactus Wren nestlings. Condor 74:492. Bent, A. C. 1948. Life histories of North American nuthatches, wrens, thrashers and their allies. U.S. Nat. Mus. Bull. 195. Bond, R. M. 1936. Some observations on the food of the Prairie Falcon. Condor 38:169-170. Dawson, W. L. 1923. The birds of California. South Moulton Co., San Francisco. Grinnell, J, and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. 13 Campy lorhynchus brunneicapillus ( con ' t . ) Hensley, M. M. 1959. Notes on the nesting of selected species of birds of the Sonoran Desert. Wilson Bull. 71:86-92. Howell, A. B. 1916. Some results of a winter's observations in Arizona. Condor 18:209-214. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. , Vol. 50, No. 6. Peters, J. L. 1960. Checklist of birds of the world. Vol. 9. (R. A. Paynter, Jr., and C. Vaurie, eds.) Mus. Comp. Zool. , Cambridge, Massachusetts. Ricklefs, R. E. 1966. Behavior of young Cactus Wrens and Curve-billed Thrashers. Wilson Bull. 78:47-56. Ricklefs, R. E. 1968. The survival rate of juvenile Cactus Wrens. Condor 70:388-389. Ricklefs, R. E. 1975. Patterns of growth in birds. III. Growth and development of the Cactus Wren. Condor 77: 34-45. Ricklefs, R. E. and F. R. Hainsworth. 1968a. Temperature dependent behavior of the Cactus Wren. Ecology 49(2): 227-233. Ricklefs, R. E. and F. R. Hainsworth. 1968b. Temperature regulation in nestling Cactus Wrens: The development of homeothermy. Condor 70:121-127. Ricklefs, R. E. and F. R. Hainsworth. 1969. Temperature regulation in nestling Cactus Wrens: The nest environ- ment. Condor 71:32-37. Ridgway, R. 1904. The birds of North and Middle America. Part III. Bull. U.S. Nat. Mus. No. 50. Selander, R. K. 1964. Speciation in wrens of the genus Campy lorhynchus . Univ. California Publ. Zool. , No. 74. pp. 135-140. Small, A. 1974. The birds of California. Macmillan Co., New York. Woods, R. S. 1932. Acquired food habits of some native birds. Condor 34:237-240. * # CALIFORNIA THRASHER Toxo stoma redivivum I TAXONOMY A. Type description Toxo stoma r. redivivum - AOU (1957) Harpes rediviva Gambel, Proc. Acad. Nat. Sci. Philadelphia, 2, no. 10, July- Aug. (Dec. 5) 1845, p. 264. (near Monterey, in Upper California.) B. Current systematic treatments Hellmayr (1934) recognized 2 races of California Thrasher, including T. r. redivivum; range listed as "Austral Zones of California west of the high Sierra Nevada and South- eastern deserts, from Monterey and Placer cos. through the San Diego district to lat. 30 in Lower California AOU (1957) considers the California Thrasher (2 races) a member of the avian order Passeriformes, family Mimidae. Grinnel and Miller (1944) give 2 races of California Thrasher in California, Sonomae (Northern California Thrasher) and redivivum (Southern California Thrasher; Mayr and Greenway (1960) also list sonomae and redivivum as the only 2 races. Specimens from the interior and southern localities were formerly recognized as T. r. pasadenenae (Dawson 1923). Engels (1940) gives very detailed study of relationships within Toxo stoma. He states that redivivum is most closely related to T. lecontei and T. dorsale. Grinnell (1921) eliminated T. r. pasadenense as a race of California Thrasher, leaving only T. r. recLTvivum in the southern portion of the state. Oberholser (1918) concluded that 3 races of California Thrasher existed: T. r. redivivum (southern California); T. r. sonomae (nortKern and central California); and T. r. Kelvum (Baja California) . C. Synonomies of scientific nomenclature Hellmayr (1934), Harpes rediviva; Harporhynchus redivivus Pasadenensis ; Toxo stoma rediviva helva; T. recLTvivum helvolum; T. r. redivivum. Grinnell and Miller (1944) list the previous names, with the addition of T. redivivum pasadenense. Toxostoma redivivum D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Curve-billed Thrush; California Mocking Bird; California Thrush; Sickle-bill Thrush; Calif- ornia Mocking Thrush; Bowbill Thrush; California Sickle- bill Thrush; Sickle-bill Thrasher; Pasadena Thrasher. II DESCRIPTION A. External morphology of adults Ridgway (1907) gives detailed account of adult and subadult plumages; "above plain deep grayish brown, the upper tail coverts and tail more. . .brown. " Peterson (1961), "A large dull gray-brown thrasher, with pale cinnamon belley and under tail coverts; tail long, bill sickle- shaped. The eye is dark brown." Robbins et al. (1966) --"note the eye stripe and dark brown body, pale rusty below." Oberholser (1918), "Brown of upper parts decidedly grayish; white of throat with little or no tinge of buffy..." B. External morphology of subadult age classes. Ridgway (1907) noted young were "essentially like adults but browner above. .. sometimes only slightly different." C. Distinguishing characteristics Interspecific - Peterson (1961), speaking of the California Thrasher, "This is the only thrasher of this type in Calif- ornia west of the desert divides." Intraspecif ic - Ridgway (1907) "Sexes alike; male: wing 102.6 mm, length 284 mm, tail 129.7 mm and female: wing 100.6 mm, length 278 mm, tail 127.2 mm." Oberholser (1918) gives detailed analysis of male and female characteristics of several races. ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) gives distribution of T. redivivum as, "Northern California south to northern Baja California. " AOU (1957) gives distribution of T. r. redivivum as, "Resi- dent from central California (Point Lobos, Paicines, El Portal, San Joaquin Valley) south to southwestern California and northwestern Baja California (El Rosario, San Fernando, western slopes of the Sierra San Pedro Martir)." ♦ ♦ Toxo stoma r. redivivum (con't.) Ridgway (1907) gives range of T. rediviyum as, "coast and interior valleys of California and northern Lower California; northward to Shasta Co., southward to San Quintin Bay, San Fernando, and San Pedro Martir Mountains." B. California distribution of the species Peterson (1961), "Resident in California (west of Sierra, deserts) from head of Sacramento Valley to N. Baja Calif- ornia." Grinnell and Miller (1944) give California range as--"coastal district from Monterey and San Benito counties south to Mexican boundary, including east slopes of mountains of southern California to limits of chaparral. .. locally on floor of San Joaquin Valley; rediyivum and sonomae inter- grade in Amador County." Small (1974), "generally west of the Sierra-Cascade crest and west of the deserts; north to Humboldt and Shasta counties; breeds." Dawson (1923) gives California range as foothills and valleys west of the Sierra Nevada. Grinnell (1917) concluded that the range of the California Thrasher in California is determined by a narrow phase of conditions in the chaparral association and within the Upper Sonoran life- zone. C. California desert distribution Grinnell and Miller (1944) give several desert sightings, including: near Hesperia, San Bernardino Co. ; San Gorgonio Pass, and near Dos Palmas. Santa Rosa Mtns. , Riverside Co. Grinnell and Swarth (1913) called them fairly common in the foothills near Banning and Cabezon, but were never seen out in the brush of the lower valleys. Found breeding near Colton, San Bernardino Co. (Willett (1953). Although little mention was given of this species desert distribution, it is apparently resident in the Little San Bernardino Mountains, with records from May (Willett 1951). A sparse population occurs on the western half of Joshua Tree National Monument, centering in the scrub oak and manzanita thickets of the Little San Bernardino Mtns. and extending east to Pinyon Wells; also noted in juniper and willow thickets of Little Morongo Canyon (Miller and Stebbins 1964). The California Thrasher has been found nesting on the desert side of the San Gabriel, San Bernardino, and San Jacinto Mountains (Bent 1948). Hanna (1936) recorded a rare nesting of this thrasher on the desert side of the San Bernardino Mountains: on 3 May 1936 near Hesperia, San Bernardino County. Pemberton (1916) found this species nesting near LeConte's Thrashers near Cabezon, Riverside Co. D. Seasonal variations in distribution Grinnell and Miller (1944) call this species a permanent resident throughout its range in California. Toxo stoma r. redivivum (con't.) IV HABITAT A. Biotopic affinities * Peterson (1961) reported chaparral, foothills, valley thickets, parks, gardens, as normal habitat. Grinnell and Miller (1944;, "Chaparral of various types; chamise, ceanothus, baccharis and sages. .utilization of informally kept gardens which offer cover." Small (1974), "lowland and coastal chaparral, riparian woodland thickets." Grinnell (1908) found the species over much of the Upper Sonoran Chaparral belt of the San Bernardino Mtns. Grinnell (1917) concluded that the California Thrasher is best adapted to life in the Upper Sonoran Zone (chaparral) of California. B. Altitudinal range "Altitudes of occurrence from near sea level... up to 5,500 ft. in the San Bernardino Mtns. (Grinnell and Miller 1944)." Dawson (1923), " a fairly uniform distribution up to about 6,000 ft." Seen at 4,900 ft. in the San Jacinto Mtns. (upper limit) by Grinnell and Swarth (1913). Noted in the scrub oak belt between 3,500 and 5,500 ft. in the San Bernar- dino Mtns. (Grinnell 1908). Willett (1933) noted this thrasher up to 5,000 ft. in southern California mountains. Grinnell (1917), "While sharply delimited. . .at the upper edge of Upper Sonoran, the California Thrasher is not so closely restructed at the lower edge of this zone." 0 C. Home range size Sargent (1940) found that thrashers defended a 0.75 acre territory all year long (Los Angeles Co.). D. Territory requirements Perch sites - Dawson (1923), "Song requires the topmost bough of ceanothus or scrub oak." Although it spends much time on the ground, this bird perches on the highest bush or tree to sing. (Martin et al. 1951). Male thrashers seen singing from palms, radio towers, rooftops, and tall trees by Sargent (1940) in Los Angeles County . Courtship and mating sites - Bent (1948) states that the top of trees and bushes are common song posts. Nest sites - Peterson (1961), "nest a twiggy cup in a bush." Dawson (1923), "nest. . .placed at moderate heights in bushes or trees, or well concealed in thickets." Nests are usually placed within a few feet of the ground, well inside a large bush or scrubby tree, according to Bent (1948). Hanna (1936) found a nest on the Mohave Desert (near Hesperia) 2 ft. high in Artemisia tridentata. Grinnell (1917), 'The nests... are located in dense masses of foliage, from 2 to 6 ft. above ^ 9 0 Toxo stoma r. redivivum (con't.) the ground, in bushes which are usually part of its typical chaparral habitat. In onl}^ exceptional cases is the nesting site located in ac..tree." E. Special habitat requirements Engels (1940) states the redivivum is rather strictly limited to the upper Sonoran life zone; occupies the chaparrel. Grinnell (1917), "The California Thrasher is unquestionably delimited in its range in ultimate analysis by temperature conditions. " F. Seasonal changes in habitat requirements V FOOD A. Food preferences Dawson (1923) lists beetles, ants, grubs, berries, and seeds. Engels (1940) notes the taking of spiders, grubs, and crickets The animal diet consists primarily of beetles, ants and other Hymenoptera, moths and caterpillars, and spiders and myriapods; plant food includes poison-oak, laurel sumac, elderberry and various other berries, buckthorn, oak, wheat, and sorghum (Martin et al. 1951). Bent (1948) states the vegetable matter slightly exceeds animal matter in the diet. Grinnell (1917) stated that 59% of the diet was plant food and 41% animal food. B. Foraging areas Dawson (1923), "it seeks its food chiefly on the ground... among the leaves." Engels (1940), "all species of Toxo stoma do much of their foraging on the ground"; gives detailed account of foraging behavior. Martin et al. (1951) also described the usually feeding area as the ground around manzanito and other chaparral on hill slopes. California Thrashers, "dig and whish the bill in leaf litter and humous layers beneath or at the edge of chaparral" (Miller and Stebbins 1964). In a Los Angeles County study, Sargent (1940) noted all foraging on the ground except for trips to a balcony feeder. Grinnell (1917) stated that over two- thirds of the foraging is done on the ground. C. Foraging strategies "When feeding on the ground, this species. . .holds their tail. .. erect. . .digs with curved beak rather than scratching with its feed (Robbins et al. 1966). "Engels (1940) states that the feet are not used for scratching; redivivum digs with the bill, using it like a pick, or as a tool with which to whish litter from side to side. Bent (1948) states that most of its animal food is obtained by raking away fallen Toxo stoma r. redivivum (con't.) leaves or by digging in the soil." Salt (1953) described this thrasher as a member of the ground-insect foraging guild in Los Angeles County. Cander (1931) notes that "during the ten minutes or so that I watched (feeding), it tried some 15 or 20 different spots, all within the radius of 4 or 5 feet... the beak served... for digging in the soft sand..." Grinnell (1917) noted that, "...the long curved bill, is used to whish aside litter, and also to dig..." D. Feeding Phenology The percentage of plant food and animal food in this species' diet is nearly equal in winter, summer and fall; in spring, however, animal matter accounts for 97% of the diet (Martin et al. 1951). E. Energy requirements Moist food, and possibly at times berries, make unnecessary the seeking of water... has made it possible for this thrasher to penetrate the marginal type of chaparral of the Monument (Joshua Tree) (Miller and Stebbins 1964). Dawson (1965) notes that California Thrashers may loose 4.7% of their body weight per day through evaporative water loss. VI REPRODUCTION A. Age at first breeding B. Territorial behavior "Members of rival pairs faced each other bill to bill... occasionally rising in an attack. .. chases varied from a few feet in length to a complete circuit of the yard." (Sargent 1940) C. Courtship and mating behavior "Song includes a great variety of phrases, many repeated" (Robbins et al. 1966). The birds apparently remain paired throughout the year (Bent 1948). Male thrashers were ob- served singing and chasing females in November: male singing continued all year (Sargent 1940). Lack (1942) states that California Thrashers maintain a loose pair-bond during winter and may thus mate for life. D. Nesting phenology Dawson (1923) gives season as March to June, with 1 or 2 broods raised. In southern California, breeds mainly in March and April; set taken in December (Los Angeles County) - 0 f I # Toxo stoma r. redivivum (con't.) (Willett 1933) . Breeding season of December to May given for interior southern California by Wheelock (1904;. In Los Angeles Co. , breeds mainly in March and April (Grinnell 1898) ; he also noted a set taken in January. Egg- laying in Joshua Tree National Monument given as March and April (Miller and Stebbins 1964). Bent (1948) gives California egg dates as 15 December to 27 June, with the height of the season in April. Sharp (1907) gives the breeding season as 18 February to 13 June, with 2 or 3 broods being raised ( San Diego Co. ) . E. Length of incubation period Wheelock (1904) gives incubation period is 14 days; both adults assist in incubation and feeding of young. Bent (1948) also gives a 14 day incubation period. F. Length of nestling period "The young thrashers leave the nest when 12 to 14 days old, but are fed by the adults for some time after (Bent 1948). G. Growth rates Wheelock (1904) summarizes general development; are fed regurgitated food until fourth day, whole items thereafter. H. Post-breeding behavior First young of the year are forced out of the nesting terri- tory by adults when a new nest rs constructed (Sargent 1940) VII POPULATION PARAMETERS A. Clutch size Eggs (2-4) pale blue, speckled (Peterson 1961). Reed (1904) gives clutch of 3-4 eggs. Dawson (1923), eggs 3 or 4. Bent (1948) cites clutch as 2-4, usually 3. In San Bernardino County, Hanna (1936) gives an average clutch as 3.07, with 83% of all nests containing 3 eggs (range = 2-4). B. Fledging success In Los Angeles County, Sargent (1940) reported the fledging of 5 young from 4 nests. C. Mortality rates per age class Sargent (1940) noted the taking of nestlings by house cats. Toxostoma r. redivivum (con't.) D. Longevity Linsdale (1949) recaptured a California Thrasher 6 years after it was banded in California. E. Seasonal abundance F. Habitat density figures California Thrashers are most abundant in the foothill and mesa regions of southern California (Willett 1933) . Jehl (1978) reported a breeding population of 2 territorial males on a 20 ha (49.42 acre) scrub oak-desert chaparral study area in Imperial Co., California. Gaines (1975) found a population of 3 territorial male thrashers on a 13.70 ha study area in "serpentine chaparral" in Napa Co. , California. Ill INTERSPECIFIC INTERACTIONS A. Predation Bent (1948) recounts the taking of a California Thrasher by a Sharp- skinned Hawk. He also notes the loss of eggs and young by skunks, banded racers, lizards, cats, and per- haps, the Scrub Jay. House cats were the chief enemies of this species in a study in Los Angeles County by Sargent (1940). Allen (1943) noted the attack of a Sharp-skinned j± Hawk on a thrasher near Berkeley in November. Edwards (1919) describes the taking of thrasher eggs by jays in southern California. B. Competition "Only the. . .LeConte' s (Thrasher) overlaps any part of this bird's U.S. range" (Robbins et al. 1966). Bent (1948) feels that the California Thrasher is able to drive most other species from a food source, including the Scrub Jay. California Thrashers were able to successfully compete with Mockingbirds for nesting sites in a study in residential Los Angeles County (Sargent 1940). C. Parasitism Friedmann (1963) does not list this thrasher as a victim of cowbird parasitism. IX STATUS A. Past population trends "Common resident below the Transition Zone in Southern Calif- ornia" (Grinnell 1915). Earlier, Grinnell (1898) called the species a common resident in Los Angeles County. Called, "one gp of our common residents," by Sharp (1907) in Escondido, San Diego Co. Toxostoma r. redivivum (con't.) B. Present population status Grinnell and Miller (1944) reported them permanently resi- dent; common under favorable conditions in many parts of range. Small (1974) called this species a common resident in California. Miller and Stebbins (1964) describe a resi- dent, but sparse, population at Joshua Tree National Monu- ment. C. Population limiting factors "In general, both high mountains and deserts constitute effective barriers to its spread" (Bent 1948). Grinnell (1917), "An explanation of this restricted distribution (of the California Thrasher) is probably to be found in the close adjustment of the bird... to a narrow range of environ- mental conditions." D. Environmental quality: adverse impacts Grinnell and Miller (1944) note that--"informally kept gardens. .. compensate in limited fashion for some of the reduction in natural habitat brought about by clearing of chaparral." Storer (1933) also felt that clearing of chaparral had reduced needed thrasher habitat in Calif- ornia. E. Potential for endangered status 10 To xo stoma r. redivivum (con't.) XI LITERATURE CITED Allen, A. S. 1943. Additional notes on the birds of a Berkeley hillside. Condor 45:149-157. American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bent, A. C. 1948. Life histories of North American nuthatches, wrens, thrashers, and their allies. U.S. Nat. Mus. Bull. 195:1-475. Davis, J. 1952. A second November nest of the California Thrasher. Condor 54:116. Dawson, W. L. 1923. The birds of California. Vol. 2. South Moulton Co. , San Francisco. Dawson, W. R. 1965. Evaporative water losses of some Australian parrots. Auk 82:106-108. Edwards, H. A. 1919. Losses suffered by breeding birds in Southern California. Condor 21:65-68. Engels, W. L. 1940. Structural adaptations in thrashers (Mimidal: Genus Toxo stoma) with comments on interspecific relationships. Univ. California Publ. Zool. 42:341-400. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233. 276 pp. Gaines, D. A. 1975. Thirty-ninth breeding bird census. Am. Birds 29:1129-1130. Gander, F. F. 1931. Thrasher psychology. Condor 33:73. Grinnell, J. 1898. Birds of the Pacific slope of Los Angeles County. Pasadena Academy Sci. No. 11:1-52. Grinnell, J. 1898. The biota of the San Bernardino Mountains. Univ. California Publ. Zool. 5:1-170. Grinnell, J. 1915. A distributional list of the birds of California. Pacific Coast Avifauna No. 11. 217 pp. Grinnell, J. 1917. The niche-relationships of the California Thrasher. Auk 34:427-433. Grinnell, J. 1921. The "Pasadena" Thrasher not a recognizable race. Condor 23:165. 11 Toxo stoma r. redivivum (con't.) Grinnell J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna. No. 27. 608 pp. Grinnell, J. and H. S. Swarth. 1913. An account of the birds and mammals of the San Jacinto area of southern California. Univ. California Publ. Zool. 10:197-406 Hanna, W. C. 1936. California Thrasher nesting on Mohave Desert. Condor 38:220. Hellmayr, C. E. 1934. Catalogue of birds of the Americas Part 7. Field Mus. Nat. Hist. Zool. Ser. Publ. 330, Vol. 13. Jehl, J. R. , Jr. 1978. Forty-first breeding bird census. Am. Birds 32:105. Lack, D. 1940. Pair- formation in birds. Condor 42:269-286. Linsdale, J. M. 1949. Survival in birds banded at the Hastings Reservation. Condor 51:88-96. Martin, A. C. , H. S. Zim, and A. L. Nelson. 1951. American wildlife and plants. McGraw-Hill Book Co. , New York. 500 pp. Mayr, E. and J. C. Greenway, Jr. Editors. 1960. Checklist of birds of the world. Vol. 9. Mus. Comp. Zool., Cambridge, Mass. 506 pp. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Oberholser, H. C. 1918. A revision of the races of Toxo stoma redivivum (Gambel). Auk 35:52-61. Pemberton, J. R. 1916. Nesting of the LeConte Thrasher. Condor 18:219-221. Peterson, R. T. 1961. A field guide to western birds. 2nd Edition Houghton Mifflin Co., Boston. 366 pp. Reed, C. A. 1904. North American birds eggs. Doubleday, Page & Co., New York. 356 pp. Ridgway, R. 1907. The birds of North and middle America. Part 4. Bull. U. S. Nat. Mus. No. 50. Robbins, C. S. , B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. 12 Toxostoma r. redivivum (con't.) Salt, G. W. 1953. An ecological analysis of three California avifaunas. Condor 55:258-273. Sargent, G. T. 1940. Observations on the behavior of color- banded California Thrashers. Condor 42:49-60. Sharp, C. S. 1907. The breeding birds of Escondido. Condor 9:84-91. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Storer, T. I. 1933. Relations between man and birds in Calif- ornia. Condor 35:55-59. Wheelock, I. G. 1904. Birds of California. A. C. McClurg and Co. , Chicago. 578 pp. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna. No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles Co. Mus. Zool. Ser. 6:1-39. Woods, R. S. 1939. The California Thrasher as a mimic. Condor 4i:30. I COMMON NIGHTHAWK Chordeiles minor » • I TAXONOMY A. Type description AOU (1957), Chordeiles virginianus hesperis Grinnell, Condor 7, no. 6, Nov. 22, 1905, p. 170 (Bear Lake, 6700 feet, San Bernardino Mountains, California). B. Current systematic treatments Selander (1954) recognizes five subspecies, giving detailed description of morphology and ranges (minor, hesperis, henryi , howelli, sennetti) . Peters (1940), recognizes four species in the genus Chordeiles, C. minor composed of 8 subspecies (minor, hesperis, sennetti, howelli, henryi , aserriensis, chapmani , vicmus , gundlachii) . Caprimalgiformes: Caprimalgidae. C. Synonomies of scientific nomenclature . AOU (1957) Chordeiles virginianus hesperis Grinnell D. Synonomies of vernacular nomenclature Dawson (1923), Bull-bat. Grinnell and Miller (1944) Pacific Virginia Nighthawk. II DESCRIPTION A. External morphology of adults Peterson (1961), "slim-winged, gray or gray-brown. . .broad white bar across pointed wing. . .male has white bar across notched tail; white throat." Ridgway (1914) detailed des- cription of adult, including plumage, soft parts and measurements. Dawson (1923), "Mottled, black, gray, and ochraceous and with white in patches; above, black pre- dominating, especially on crown and back, mottling falling into indistinct bars on upper tail-coverts and tail... a large inverted V-shaped throat patch white, the chest, in sharp contrast, chiefly black." Adult female similar but lacking white band, possessed by male, on notched tail. Selander (1954), in areas where night hawks necessarily are restricted to one or a few habitats, .. .a correspondingly narrow range of variation, while more environmentally diverse regions are. . .able to support a wider range of color and pattern types." Ghordeiles minor ( con ' t . ) ^^ B. External morphology of subadult age classes ^ Ridgway (1914), "Much like the adult female but without a wall defined (if any) white throat-patch, the chin and throat being buffy barred or transversely spotted with dusky- -usually, however, with more or less of an indication of the throat-patch of adults in the form of a less heavily spotted or barred (sometimes immaculate) buffy or whitish A- shaped area across middle of throat; gentle cast of upper parts decidedly paler, on account of more numerous and smaller pale markings, the wing-coverts especially having pale grayish or buffy grayish largely predominating, and barring of under parts less sharply defined." C. Distinguishing characteristics Interspecific - Peterson (1961), larger than lesser night- hawk. White in wing further away from tip. Flies high in the air. Intraspecif ic - III GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) "Breeds from northern Washington (east of the Cascade Mountains) and southeastern British Columbia (Trail, Cranbrook) south to northwestern California (rarely to Humboldt Bay) , in interior of California from the Sierra Nevada to the San Bernardino Mountains, and through western Montana, northwestern Wyoming (Yellowstone Park) , and Idaho to central Nevada (Sharp) and central Utah." B. California distribution of the species Small (1974), "Cascades, Sierra Nevada, and in the Transi- tion Ranges, the San Bernardino Mountains." Dawson (1923), "Summer resident in high Transition and Boreal zones in northern California from the Warners to the Coast, and south through the Sierras and adjacent highlands to Tulare County. Also in the San Bernardino Mountains. C. California desert distribution Miller (1951) San Bernardino region. Grinnell and Miller (1944) San Bernardino Mountains; Lone Pine, Cottonwood Lakes. Death Valley (Inyo County); Pasadena, Los Angeles County. • ♦ • Chordeiles minor (con't.) D. Seasonal variations in distribution AOU (1957): "Winter range unknown; presumably in South America. Recorded in migration in Colorado (Estes Park), Kansas (Hamilton), New Mexico (Tres Piedras), Texas (Brown- wood), Louisiana, Campeche, and Nicaragua." Small (1974), "summer visitor (California) and transient, April to end of October." IV HABITAT A. Biotopic affinities Peterson (1961), "Treeless plains to mountains, open pine woods." Small (1974), "coniferous forest of Transition and lower Canadian Life Zones." Dawson (1923). "high Boreal and Upper Transition zones." Miller (1951) Transition, Canadian, and Hudsonian zones. Grinnell and Miller (1944), "open type of coniferous forest with exposed, usually rocky or gravelly ground for 'nest sites. ' Most frequent asso- ciated trees: yellow pine, white fir, and lodge-pale pine." B. Altitudinal range Dawson (1923) "July 5, 1911, charging above over the melting snowbanks at the Cottonwood Lakes (el. 11,000 ft.)... Dr. Grinnell took eggs at an altitude of 9000 feet on San Gorgorio Peak." Selander (1954) "altitudinally from tree line down to the lower limits of the Upper Sonoran Zone." C. Home range size Armstrong (1965) thirteen neighboring nighthawk breeding home ranges in the center of Detroit, Michigan included on the average 10.4 ha total area. . .variation in home range size seems best explained by birds settling thickly where flat roofs are numerous. . .and by birds not settling at all where roofs are scarce, and by home ranges next to such unoccupied areas expanding into them and/or at the expense of neighbors who must defend their entire boundaries. D. Territory requirements Perch sites - Rust (1947) "When mated, the^ male selects a roost in a nearby tree." Courtship and mating sites - Dawson (1923), description of aerial courtship flight of male. Nest sites - Dawson (1923)"... on bare ground, often among rocks, sometimes upon a flat rock, or on the gravel roof of a tall building. .. eggs. . .practically invisible to the Chordeiles minor (con't.) searching eye even though they rest upon the bare ground or upon an exposed and lichen- covered rock ledge." Rust (1947) "low foothills or the extreme ends of the lower ridges or benches in opening not far from trees... on low flats or pasture land free from dense grass or thick weed beds... female invariably selects the nesting area." E. Special habitat requirements Gaccamise (1974), "feeding is generally done on or near the territory. . .an effective means of minimizing. .. time and energy required to travel to distant feeding sites, pro- viding that territories with sufficiently high concentra- tions of food were available." Cowles and Dawson (1951), "The fact that insects are more abundant near sources of water may serve to restrict Nighthawk populations to nearby areas, thus indirectly limiting them to nesting sites within flying distance to water. F. Seasonal changes in habitat requirements V FOOD A. Food preferences Dawson (1923), "One Nighthawk stomach under examination gave up seventeen species of beetles at one time. Another, nineteen entire grasshoppers. Another, parts of thirty- eight. But if the Bullbat has a speciality, it is flying ants." Caccamise (1974), "often one or two species of insects made up 90-100% of the total food weight. .. flying ants often make up a large proportion of the diet... are probably selected over most other foods. Knowlton and Harmston (1943) "Four stomachs were examined; one contained nine winged grasshoppers." Blake (1941) "known to feed on termites." B. Foraging areas Small (1974), "forages over lakes, valleys, meadows, and rivers." Grinnell (1944) "broad, open fly-ways, over moun- tain meadows, lakes, larger stream courses, and lower valleys adjacent to mountains." C. Foraging strategies Caccamise (1974), "opportunistic feeders, taking that food which is most abundant and most easily captured (on the wings). ...may seek... areas where there are high concentrations of insects..." Armstrong (1965) "active, catching flying insects, mostly during twilight and night." ♦ Chordeiles minor ( con ' t . ) D. Feeding Phenology- Rust (1947) "The gathering of the nesting Nighthawks from the various nesting locations from all directions for the evening feeding was found to be remarkably regular. . . shortly after males leave for feeding, they are followed by incubat- ing females, which leave their eggs for a brief period and join the feeding group... if a large swarm of insects is found, all the nighthawks present over the area will con- centrate in a close group and move in small circles in a rather slow flight. . .when insufficient food has been obtained in the air, they will do some feeding on the ground or in the vicinity of their nesting sites. E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Weller (1958), "the territory. .. seemed well defined and clearly outlined by his flight pattern during the hen's I period of incubation. . .another male frequented an adjacent area, and some chasing occurred when either male strayed into the other's territory." C. Courtship and mating behavior Dawson (1923) "After much preliminary shifting and many emphatic bayards he suddenly casts himself head long down the air in a great parabola of flight. As he turns sharply and at break-neck speed, he produces a bud booming' daw-w' . " D. Nesting phenology Dawson (1923), June, one brood. Weller (1958), reports that second clutches occur. "The male assumed the respon- sibility for feeding the young of the first brood while the female incubated the second clutch." E. Length of incubation period Rust (1947), 18-19 days. F. Length of nestling period ♦ Rust (1947), young are able to move around in nesting area after latching. "At the age of 18 days they are able to fly short distances and can fly well at the age of 25-30 days, although the primaries are not yet fully developed." Chordeiles minor (con't.) G. Growth rates Rust (1947), measurements of primaries and total length of young up to age 30 days. H. Post-breeding behavior Hansen (1950) observed flocks of up to 75 individuals from 20 initially (July through September) , discusses daily east-west movements in mornings and evenings (Hovenweep Nat. Monument, Colorado) ... feeding flocks, not migrants. Rust (1947) "as soon as the young nighthawks are able to fly well, they begin to appear among the adult birds at feeding time... at certain times in the summer... the young congregate in a large flock in fairly close formation and exercise and feed just above the ground. . .adults also have a group flight, in which they engage several evenings before the migration flight. .. similar to that of the young but at much greater heights." VII POPULATION PARAMETERS A. Clutch size Rust (1947), mostly 2 eggs, sometimes one egg. B. Fledging success 4 C. Mortality rates per age class D. Longevity E. Seasonal abundance Grinnell and Miller (1944), "Summer resident within breeding ranges, elsewhere detected sparingly as a transient, chiefly in September and October." F. Habitat density figures Dawson (1923), "While not at any time strictly gregarious, favorable conditions are likely to attract considerable numbers... to a given spot... seen dozens of birds at one time winging noiselessly. . .over the tranquil waters of an inland lake, and on several occasions companies from one to two hundred. .. over a well-watered pasture." Evidence that large numbers are not limited to migration. Snyder (1950), reports density of breeding birds in coniferous forest in Colorado as 5 per 40 ha. (average) . ♦ Chordeiles minor (con't.) Selander and Preece (1951), "In desert areas where trees or other such roosting sites are not available. . .birds do not congregate in large roosting flocks. In such regions ...feed in small groups and at sunset have been observed to fly low over the ground and scatter before alighting to roost for the night." Rust (1947), "four sets of eggs or nests were found in one pasture of twenty acres; two sets were found on a low ridge 210 yards apart and two nests were found on a low hillside 52 yards apart." VIII INTERSPECIFIC INTERACTIONS A. Predation B. Competition Caccamise (1974), "the breadth of habitat utilization of C. minor is decreased within the sympatric distribution while that of C. acutipennis seems unchanged. .. the presence of C. acutipennis precludes use of lowland habitats by C. minor within sympatric distribution. . .C. minor spends more time excluding C. acutipennis from its territories than excluding members of its own species. .. the divergence in #food niches between sexes is greater for C. minor than for C. acutipennis." Detailed discussion of competitive re- la tTolisT:iips~~wTth acutipennis. C. Parasitism IX STATUS A. Past population trends Grinnell and Miller (1944) "Summer resident within breeding range; elsewhere detected sparingly as a transient, chiefly in September and October. In metropolis, common; even 'abundant' in some favored places." B. Present population status C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status ♦ Chordeiles minor ( con ' t . ) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Armstrong, J. T. 1965. Breeding home range in the Nighthawk and other birds. Ecology 46:619-629. Bent, A. C. 1940. Life histories of North American cuckoos, goatsuckers, hummingbirds and their allies. U.S. Nat. Mus. Bull. No. 176. Blake, C. H. 1941. Termites taken by birds. Auk 58:104. Caccamise, D. F. 1974. Competitive relationships of the Com- mon and Lesser Nighthawks. Condor 76:1-20. Cowles, R. B. and W. R. Dawson. 1951. A cooling mechanism of the Texas Nighthawk. Condor 53:19-22. Dawson, W. L. 1923. The birds df California. Vol. II. South Moulton Co., San Francisco. Grinnell, J. and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. Hansen, C. G. 1950. Notes on flights of the Nighthawk. Condor 52:40-41. Knowlton, G. F. and F. C. Harms ton. 1943. Grasshoppers and crickets by Utah birds. Auk 60:589-591. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. 50: 531-624. Peters, J. L. 1940. Checklist of birds of the world. Vol. IV. Mus. Comp. Zool., Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. 309 pp. Ridgway, R. 1914. The birds of North and Middle America. Part VI. Bull. U.S. Nat. Mus. No. 50. Rust, H. J. 1947. Migration and nesting of Nighthawks in northern Idaho. Condor 49:177-188. Selander, R. K. 1954. A systematic review of the booming nighthawks of western North America. Condor 56:57-82. Chordeiles minor (con't.) Selander, R. K. and S. J. Preece. 1951. Cock roosts of Night- hawks. Condor 53:302-303. Small, A. 1974. The birds of California. Macmillan Co., New York. Snyder, D. P. 1950. Bird communities in the coniferous forest biome. Condor 52:17-27. Weller, M. W. 1958. Observation on the incubation behavior of a common Nighthawk. Auk 75:48-59. • f # ♦ DOWNY WOODPECKER (Picoides pubescens turati) I TAXONOMY A. Type description Picus turati - AOU (1957) Malherbe, Monogr. Picidees, vol. 1, 1860, P. 125 (vol. 3, pi. 29, figs. 5-7). (California . . .non loin de Monterey = near Monterey, California.) B. Current systematic treatments AOU (1957) calls this species Dendrocopos pubescens turati (Malherbe) and a subspecies of the Downy Woodpecker. Fisher (1902) called it Dryobates pubescens turati , founded on Picus turati of Malhebe. This species was synonymized to Picoides by Morony, et al. (1975; after the genus Dendrocopos recognized by Peters (1948). C. Synonomies of scientific nomenclature Grinnell and Miller (1944) in describing Dryobates pubescens turati , "Picus gardineri ; Picus gairdneri; Picus meridionalis ; Picus turati; Dryobates turati ; Picus pubescens gairdneri, part; Picus pubescens ; Dryobates pub"escens; Dendrocopus pubescens; Dendrocopus gairdneri; Dryobates pubescens oreoecus, part; Dryobates pubescens gairdneri, part. Peters (1948), "Dendrocopos pubescens turati." D. Synonomies of vernacular nomenclature Grinnell and Miller (1944) in describing the Willow Downy Woodpecker, "Gairdner Woodpecker, part; Little Georgian Woodpecker; Downy Woodpecker; Batchelder Woodpecker; part; Willow Woodpecker." II DESCRIPTION A. External morphology of adults Peterson (1969), "Note the white back, small bill... clear white back. .. spotted with white on wings; males with a small red patch on back of head; females, without." Udvardy (1977), "Black forehead, crown, and bridle across the eyes contrast with white face, underparts, and central part of back; wings checkered black and white. Male has red patch on nape." Dawson (1923), reports similar to D. villosus orius but smaller with darker underparts - reTer to that description. Length 146-158 (5.75-6.25); tail 55 (2.165); bill 16 (.63); tarsus 16.1 (.63). B. External morphology of subadult age classes Picoides pubescens turati (con't.) C. Distinguishing characteristics Interspecific - Peterson (1969) reports Ladder-backed Wood- pecker has black and white striped back while Downy has a white back. Hairy Woodpecker is a larger bird, especially the bill. Hairy has no spots on outer tail feathers. Robbins, Bruun, Zim (1966;, "Barred outer tail feathers when sizable are diagnostic (they are rarely unbarred like Hairy' s). May be mistaken for a sapsucker, whose white stripe is on the wing, not the back." Udvardy (1977), "A smaller version of the Hairy Woodpecker, with bill propor- tionately shorter and more slender and with barred outer tail feathers." Intraspecific - Bent (1939), "Smaller than D. p_. gairdneri, with smaller feet; underparts lighter; the elongated super- ciliary patch and rectal stripe extending over sides of neck, pure white, instead of smoky white of gairdneri ; tertials always more or less spotted with white. .. differs from (D. £. pubescens) in having much less white on the wings, tKe coverts and tertials of pubescens being conspicuously and often heavily marked with white." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) in describing P. pubescens, "From southeastern Alaska, southwestern Mackenzie, northern Alberta, central Saskatchewan, northern Manitoba, James Bay, southern Quebec, Anticosti Island, and Newfoundland south to southern Calif- ornia, central Arizona, northern New Mexico, south-central Texas, and the Gulf coast from Louisiana to Florida. Recorded in England (Dorset, 1836; Gloucester, 1908)." In describing P. p_. turati , "Breeds from north-central Washington (Okanagan County) southward along the east slopes of the Cascades through southwestern Oregon (Josephine, Jackson, and Klamath counties), the greater part of Calif- ornia west of the Sierra divide (except the humid coast belt from Mendocino County northward), including the deserts, and west-central Nevada in the valleys of the Treckee, Carson, and Walker Rivers." B. California distribution of the species Grinnell and Miller (1944), "Life-zone, characteristically Upper Sonoran, but at margins of general range. . .Transition. " Lists numerous site and specimen records throughout the birds' California rctnge. Small (1974), "Length of state except eastern slope of Sierras from Lake Tahoe south and entire eastern and southeastern desert areas." Miller (1951) gives various California area locations. Grinnell (1915) gives California locations, also. Dawson (1923), » # ♦ Picoides pubescens turati (con't.) "resident in Upper Sonoran and Transition zones of California, except in extreme northwestern and northeastern sections and in the desert mountains." Mailliard (1918) found them in Yosemite Valley. C. California desert distribution Small (1974) says they are NOT found in eastern and south- eastern desert areas. Grinnell and Miller (1944) give the life-zone as "characteristically Upper Sonoran." Grinnell (1902), "Breeds chiefly in Upper Sonoran zone west of the Sierran divide, except in the extreme northwest humid coast belt." Various sites are given. Willett (1933) also gives locations. D. Seasonal variations in distribution Grinnell (1915) reported it as being characteristically associated with willow growths of the valleys in breeding season. Also, that there is a more widely distributed winter population, locally. Grinnell (1902) also reported it as breeding chiefly in Upper Sonoran west of the Sierras. Dawson (1923), "...in winter it may make. .. excursions into the desert." IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), "Markedly restricted to riparian soft-woods, willow and cottonwood. . .Thus the lowland stream- bottoms constitute the main theaters of activity. . .Possibly, available water is a factor for presence. But there is some invasion of the oak belts, locally, even of tracts of coni- fers; and deciduous orchard trees, notably apple, satisfy the birds' needs." Small (1974), "Riparian woodlands." Miller (1951) found them in Lower Sonoran and Transition zones and in coastal forest. Bent (1939), "Downy Woodpeckers were seen most often close to streams and in orchards. ' Peterson (1969), "Broken or mixed forest, woods, willows, poplars, river groves, orchards, shade trees." Robbins, Bruun, Zim (1966), "Seen in suburbs, orchards, shade trees, and woods." Udvardy (1977), "Broken or mixed forests; often found in conifers but feeds and nests chiefly in young deciduous trees. Also frequents orchards, city parks, and suburban areas." Dawson (1923), "...chiefly confined to deciduous timber, and shows a great preference for wooded bottoms and the borders of streams. Willow trees are every- where its most natural associations." Bendire (1895), "It is partial to rather open and cultivated country, inter- spersed here and there with small woods and orchards; and to scattering trees and shrubbery of river and creek bottoms, Picoides pubescens turati (con't.) the shade trees along country roads, and along the edges of clearings. . .it does not seem to care for burnt tracts." B. Altitudinal range Grinnell and Miller (1944) give altitudes of nesting from near sea level to 6,100 feet. C. Home range size D. Territory requirements Perch sites - Bendire (1895), "In winter, they dig shallower excavations in dead trees, old stumps, or fence posts in some sheltered situation, in which they spend the nights, and to which they retire in stormy weather." Courtship and mating sites - Bendire (1895) reported that males drum on resonant dry limbs to attract females. Nest sites - Grinnell and Miller (1944), "Markedly restricted to riparian soft-woods, willow and cottonwood. . . some inva- sion of oak belts. .. tracts of conifers, and deciduous orchard trees, notably apple. . .Branches of boles of these trees must be far advanced in decay to be excavatable for nest or shelter purposes." Small (1974), ". . .nest. . .on the trunks ...of small trees." Grinnell (1915) reported them as being associated with willow growths in the breeding season. Peterson (1969), "In hole in tree." Udvardy (1977), "... nests chiefly in young deciduous trees... in a hole in a dead tree." Dawson (1923), "A hole excavated by the birds in tree, usually deciduous, as willow, cottonwood, alder, and the like; at moderate heights." Bendire (1895) reported nest at 4-20 feet from ground and usually no higher. Prefers apple, cherry, pear oak, maple poplar, alder, linden, ash, willow and magnolia, especially in dead limbs. E. Special habitat requirements Grinnell and Miller (1944), "possibly, available water is a factor for presence." Bendire (1895), "Its breeding sites seem to be confined to deciduous trees, preferably dead ones, or old stumps." Ligon (1970) reports that they need standing dead timber to breed. F. Seasonal changes in habitat requirements Grinnell (1915) reported them as being associated with willow growths during breeding. Dawson (1923) reported that areas of increased insect density were required to feed the young birds during nestling season since the adults do not have a large foraging range then. t 0 Picoides pubescens turati (con't.) V FOOD A. Food preferences Bendire (1895) reported that the food was similar to the Downy Woodpecker's diet, i.e., larvae and eggs of insects, occasionally berries and seeds. He also reported that they eat ants and spiders and raw meat. B. Foraging areas Small (1974), "Forage. . .on the trunks... of small trees." In Bent (1939), "Their forage places included the limbs or small trunks of willow, alder, cottonwood, sycamore, valley oak, blue oak, digger pine, and yellow pine trees." Udvardy (1977), ".. .feeds. . .chief ly in young deciduous trees. ' Dawson (1923), "Foraging expeditions are regularly undertaken into neighboring groves of live oak or pine, and... to apple orchards." C. Foraging strategies Udvardy (1977), "...the male is larger than the female and has a longer, stronger bill and chisels deep into wood, whereas the female pries under the bark with her shorter bill. Thus, a pair shares the food resource without com- peting with one another." Bendire (1895), "It begins near the roots and carefully scans every cranny as it hops along, looking now at one side and then on the other." Kisiel (1972) discusses how Hairy and Downy Woodpeckers divide the resources by feeding on different species of trees. D. Feeding phenology E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Bendire (1895), "Each pair of birds lay claim to a certain range, and intruders on this are driven away." Kilham (1962) describes defense of territories against others of the same species. t Picoides pubescens turati (con't.) C. Courtship and mating behavior Bendire (1895) reported that males drum on limbs and attract females. Both sexes build nest and care for young. Kilham (1962) also described drummings and tapping as well as displays used in courtship. Both sexes take part in nest building and incubation. He also describes preening and other courtship-related activities (1972), as well as saying they maintain year-round pair bonds. D. Nesting phenology Willett (1933) reported breeding to start in April and May. Dawson (1923), "Nesting - April-May; one brood. Young are hatched some time in May." Bendire (1895) reports nesting starts in mid-April in southern California. E. Length of incubation period Dawson (1923), "12 days." Bendire (1895), "about 12 days." F. Length of nestling period G. Growth rates H. Post-breeding behavior Dawson (1923), "One brood." Bendire (1895) reported one brood, normally. Young are also cared for after they leave the nest. VII POPULATION PARAMETERS A. Clutch size Willett (1933) reports 5 and 7 egg clutches. Bent (1939) reports 3-6 eggs, more commonly 4 or 5, sometimes 7. Peterson (1969; reports 4-7, as does Udvardy (1977). Dawson (1923) reports 4 or 5, 7 of record. Bendire (1895), "Four or five eggs... one laid daily." B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abundance Neff (1928) describes them as being more abundant within a given area in winter than in summer, presumably because they tend to associate only in pairs in the other seasons. » Picoides pubescens turati (con't.) F. Habitat density figures Koplin (1969) reports that density changes as the amount of prey items change due to fire and floods. E.g., there is a fifty-fold increase in response to insect increase after a fire. Short (1971) states that these birds need smaller territories than Hairy Woodpeckers, and thus have denser populations. VIII INTERSPECIFIC INTERACTIONS A. Predation B. Competition Ligon (1973) reports competition for food with White-headed Woodpeckers in Idaho, and (1970) competition for nesting sites with the Red-cockaded Woodpeckers. C. Parasitism IX STATUS A. Past population trends w Grinnell (1902) reported this species as a "common resident in suitable localities almost throughout the State," and (1915) as a "common resident locally, chiefly in Upper Sonoran Zone west of the Sierran divide except in the ex- treme northwest humid coast belt." Willett (1933) reported it as a common resident in willow regions of lower country. B. Present population status Grinnell and Miller (1944) reported it as permanently resi- dent. Locally common with about normal marginal vagrancy in autumn. Small (1974) reported it as a resident. Ligon (1970) feels that there are more of this species in open pinelands now than previously. C. Population limiting factors Grinnell and Miller (1944) and Ligon (1970) both report that if diggable wood (especially standing dead timber) is reduced, so is the bird population. t D. Environmental quality: adverse impacts Grinnell and Miller (1944), "Repeatedly, elimination of all such diggable wood is a given neighborhood has been observed to be followed by disappearance of the birds." Ligon (1970) reports that they need dead standing timber to breed, and re- peated fired reduce this. Picoides pubescens turati (con't.) E. Potential for endangered status • Picoides pubescens (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957." Checklist of North American Birds. 5th Edition. American Ornithologists' Union. The Lord Baltimore Press, Inc. Baltimore, Mary- land. 691 pp. Bendire, C. 1895. Life histories of North American birds. Volume 2. Smithsonian Contributions to Knowledge #985. Smithsonian Institution. Washington, D.C. 518 pp. Bent, A. C. 1939. Life histories of North American Wood- peckers. Smithsonian Institution. United States National Museum Bulletin #174. U.S. Gov't. Printing Office, Wash- ington. 334 pp. Dawson, W. L. 1923. The birds of California. Volume Two. South Moulton Company. San Diego. 1432 pp. Fisher, W. K. 1902. The Downy Woodpeckers of California. The Condor. 4(3): 68-70. Grinnell, J. 1902. Checklist of California birds. Pacific Coast Avifauna #3. Cooper Ornithological Club. Santa Clara, California. 98 pp. Grinnell, J. 1915. A distributional list of the birds of California. Pacific Coast Avifauna #11. Cooper Ornith- ological Club. Hollywood, California. 217 pp. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna Number 27. Cooper Ornithological Club. Berkeley, California. 608 pp. Kilham, L. 1962. Reproductive behavior of Downy Woodpeckers. Condor 64:126-133. Kisiel, D. S. 1972. Foraging behavior of Dendrocopos villosus and D. pubescens in Eastern New York State. Condor 74: 393-399. Koplin, J. R. 1969. The numerical response of woodpeckers to insect prey in a subalpine forest in Colorado. Condor 71:436-438. Ligon, J. D. 1970. Behavior and breeding biology of the Red- cockaded Woodpecker. Auk 87:255-278. Ligon, J. D. 1973. Foraging behavior of the White-headed woodpecker in Idaho. Condor 90:862-869. 10 Picoides pubescens (con't.) Mailliard, J. 1918. Early autumn birds in Yosemite Valley. Condor 20:11-19. Miller, A. 1951. An analysis of the distribution of the birds of California. University of California Publications in Zoology. Vol. 50, #6, pp. 531-644. Morony, J. J. Jr., W. J. Bock, J. Farrand, Jr. 1975. Reference list of the birds of the world. The American Museum of Natural History, New York. 207 pp. Neff, J. A. 1928. A study of the economic status of the common woodpeckers in relation to Oregon Horticulture. Free Press Print, Marionville, Mo. 68 pp. Peters, J. L. 1948. Checklist of birds of the world. Vol. VI. Harvard University Press, Cambridge. 259 pp. Peterson, R. T. 1969. A field guide to western birds. Houghton Mifflin Company. Boston. 366 pp. Ridgway, R. 1914. The birds of North and Middle America. Part VI. Bull, of the U.S. Nat'l. Museum. Gov't. Print- ing Office. Washington, D.C. 882 pp. Robbins, C. S. , B. Bruun, H. S. Zim. 1966. Birds of North America. Western Publishing Company, Inc. Racins, Wiscon- sin. 340 pp. Short, L. L. 1971. Systematics and b avior of some North American woodpeckers, Genus Picoides (Aves) . Bull, of the Am. Mus. of Nat'l. Hist. vol. 145: Article 1, pp. 1-118. Small, A. 1974. The birds of California. Winchester Press. New York. 310 pp. Udvardy, M. D. F. 1977. The Audubon Society Field Guide to North American Birds. Alfred A. Knopf, Inc. New York. 855 pp. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna #21. Cooper Ornitholo- gical Club, Los Angeles, California. 204 pp. t 0 $ FOX SPARROW Passerella iliaca I TAXONOMY A. Type description AOU (1957), Passerella iliaca: Passerella Swainson, Nat. Hist. Class. Birds, vol. 2, July 1, 183/, p. 288. Type by monotypy, Frinqilla iliaca Merrem. Passerella iliaca zaboria Oberholser, Journ. Washington Acad. Sci., Jb, no. 11, Nov. 15, 1946, p. 388. (Circle, Alaska. ) P. i. sinuosa Grinnell, Univ. California Publ. Zool., 5, no. 12, Mar. 5, 1910, p. 405. (Drier Bay, Knight Island, Prince William Sound, Alaska.) P. i. schistacea described as, P. schistacea Baird, in B"aird, Cassin, and Lawrence, Rep. Expl. and Surv. R. R. Pac, vol. 9, 1858, pp. xl, 488, 490. (Head of the Platte = South fork of Platte River, about 25 miles east of the northeastern corner of Colorado, in Nebraska.) P. :L. canescens Swarth, Proc. Biol. Soc. Washington, 31, no. 40 . , Dec . 30 , 1918, p. 163. (Wyman Creek at 8250 feet altitude, east slope of White Mts., Inyo County, California.) P. i. megarhyncha described as, P. megarhyncha Baird, Cassin and Lawrence, Rep. Expl. and Surv. R.R. Pac. , vol. 9. 1858, pp. xl, 925. (Fort Tejon, [Kern County, California].) P. i. monoensis J. Grinnell and T. I. Storer, Condor, 19, no. 5, Sept. 25, 1917, p. 165. (Mono Lake Post Office, altitude 6500 feet, Mono County, California.) P. i. stephensi Anthony, Auk, 12, no. 4, Oct. 1895, p. 348. "CJTahquitz ValleyJ San Jacinto Mts., California.) B. Current systematic treatments AOU (1957) places the species P. iliaca in the Order Passeri- formes, Family Frinqillidae, Subfamily Emberizinae, with 18 subspecies. Mayr and Short (1970): "The Fox Sparrow is highly variable. Its variation has been treated by Linsdale (1928a, b), by Oberholser (1946), and by Behle and Selander (1951). Distinctive races include the insular unalaschensis and insularis, as well as various continental races. The Fox Sparrow seems closely related to P. melodia." Martin (1977) discusses Fox Sparrow relationships to other emberizids according to song. Linsdale (1928) suggests that Passerella and Melospiza properly belong in the same genus, as does Paynter (,1964) while Parkes (1954) maintains they should be separate. Passerella iliaca (con't.) C. Synonomies of scientific nomenclature AOU (1957) lists the two synonomies as above. Grinnell and Miller (1944): for sinuosa, P. i. townsendi, part; P. i. unalaschensis, part; P. i. insuTaris, part; P. ^L. meruToides, part; for me g" ar hync hu s , P. schistacea, part; P. townsendi var. megarhynchus , part; P. schistacea var. megarhynchus ,' part; P. i. mariposae; P. i. monoensis, parti for cane sc ens, P. _i. schistacea: for stepKensi, P. schistacea, part; P. townsendi var. schistacea, part;_F. townsendi var. megarhyncha, part; P. megarhyncha, part; P. stephensi, part: ana for several others they say, "Inability to verify racial identity of many early records of Fox Sparrows renders a complete listing of names futile." D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), sinuosa: "Oregon Finch, Townsend Sparrow, Shumagin Fox Sparrow, Kodial Fox Sparrow, Yakutat Fox Sparrow." Schistacea, monoensis, "Inability to verify racial identity. . . " Megarhynchus : "Large-beaked Sparrow, Slate-colored Sparrow~ Thick-billed Sparrow, Thick-billed Fox Sparrow, Yosemite Fox Sparrow, Mono Fox Sparrow." Canescens: "Slate-colored Fox Sparrow, Inyo Fox Sparrow, StepheniT: "Slate-colored Sparrow, Thick-billed Sparrow, ^k Stephens ' Sparrow." II DESCRIPTION A. External morphology of adults Dawson (1923), P. _i. sinuosa, "Similar to P. I. insularis, but still darker (as compared with unalascKensis) and less rufescent." P. i. schistacea, "Somewhat similar to P. _i. _i. but rufous spots somewhat smaller with tail longer - nearly equal to wing; rufous element in plumage greatly reduced; pattern of upper plumage entirely blended; streaking of underparts about equal in quantity but slightly dusky or brownish instead of red. Color of upperparts, brownish gray; more rufuscent, dull cinnamon brown, in upper-tail coverts and exposed surfaces of wings and tail; below white, sharply streaked, especially on the chest and sides with spots of dark brown; streaks tend to confluence on sides of throat; those of the sides are prolonged and enlarged posteriorly. Bill slightly smaller and darker, feet darker than iliaca. " "P. i, canescens, "From schistacea, canescens may be dit terentTated by ics decidedly more grayish colora- tion. A dubious candidate for nomenclatural recognition, albeit the tendency toward grayishness does exist." P. _i. monoensis, "Similar to P. i. schistacea, but slightly grayer and with much stouter bill - comparable in this regard to ^^ Passerella iliaca (con't.) P. i_. fauva, which is a much browner bird. Monoensis is possibly the lightest of the recognizable forms of iliaca. ' The affinities of monoensis are with mariposae, and it pro- bably does not deserve nomenclatural distinction from it." P. i. stephensi, "Similar to P. i^. mariposae in coloration, "But size averaging slightly larger and bill at maximum of development, relatively enormous. Bent (1968) in a description of the western mountain sub- species of P. iliaca says, "In these nine races the tail is at least (rarely)" equal to and usually longer than the wing. Grays predominate in their coloration, increasingly so from north to south, and the rather pale uniform gray head and back contrasts with the dull reddish-brown wings and tail. The spots and streaks of the underparts are dull. The bill is large and somewhat swollen, increasingly so from east to west in the California forms. ' Baird et al . (1905): "General aspect of upper parts foxy-red the ground- color and the sides of the neck being ashy; the interscapular feathers each with a large blotch of fox-red; this color glossing the top of the head and nape; sometimes faintly, sometimes distinctly; the rump unmarked; the upper coverts and surface of the tail continuous fox-red. Two narrow white bands on the wing. Beneath with under- tail coverts and auxillars, clear white, the sides of the head and throat, the jugubum, breast, and sides of body, conspicuously blotched with fox-red. Sometimes the entire head above is continuously reddish." B. External morphology of subadult age classes C. Distinguishing characteristics Interspecific - Robbins et al. (1966) comments that Western Fox Sparrows are deeper brown or gray-brown than eastern races. Peterson (1961): "The many races can be divided into three types: (1) bright rusty Fox Sparrows; (2) dark- brown headed with darker bills; (3) gray-headed with large yellowish bills. The only race identified readily is the Yukon Fox Sparrow (zaboria) ." Ridgway (1915) provides a key to some of the races. ' Phillips et al . (1964) state that the study of the variation of the races has been thrown off track by failure of investigators to take into account seasonal wear, which causes color variations. Wolf son (1955) mentions Linsdale's study (1928) in which individual varia- tion in bone size was found to be slight when compared to geographic variation. Gabrielson and Jewett (1940) state that trying to identify races in the field is hopeless due to the variation, and close relation of subspecies. Passerella iliaca (con't.) Intraspecific - Robbins et al. (1966): "This may be confused with Hermit Thrush except for the yellow lower mandible and slightly notched tail." Peterson (1961): "Larger than the House Sparrow. Hermit Thrush has a similar reddish tail, but is thin-billed and spotted rather than stripped." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) Passerella iliaca: "Northern Alaska, northwestern and central eastern Mackenzie, northern Manitoba, northern Ontario, northern Quebec, and northern Labrador south on the Pacific coast to northwestern Washington; in the moun- tains to southern California, central Nevada, central Utah, and central Colorado; and to central Alberta, central Saskatchewan, southern Manitoba, central Ontario, southern Quebec, and Newfoundland." P. i. zaboria: "Breeds from northwestern and interior Alaska, northern Yukon, northwestern and central eastern Mackenzie, and northern Manitoba south to northern British Columbia, central Alberta, and central Saskatchewan, and southern Manitoba." P. i. sinuosa: "Breeds in the Kenai Peninsula and Prince William Sound districts (25 miles north of Valdez, Cordova) and on Middleton Island, south central Alaska." P. i_. schistacea: "Breeds from southeastern British Columbia and southwestern Alberta south through the mountains of northern Idaho, north-central and eastern Oregon, and western Montana, to north-central and northeastern Nevada, south- western Wyoming, and central Colorado." P. _i. canescens: "Breeds in central Nevada and extreme central eastern California (White Mountains). P. i. megarhyncha: "Breeds in mountains from southwestern Uregon south through central and northern California and the Sierra Nevada of California to lat. 37° N. ; locally to west-central Nevada in the Tahoe district." P. i. monoensis : "Breeds in the Mono district on the east "Flank of the central Sierra Nevada in California; locally in adjoining Mineral County, Nevada." P. i. Stephen si : "Breeds in the southern Sierra Nevada of "CalTfornia ana in the high mountains in southern California (Mount Pinos, San Gabriel, San Bernardino, and San Jacinto mountains. " f # Passerella iliaca (con't.) Phillips et al. (1964): "Fox Sparrows nest clear across the northern part of the continent and extend southward in the west to the Rockies of Colorado and Utah and to the high mountains of southern California." They consider P. i^. zaboria an eastern bird due to tail size and coloration, but list Alaska as its breeding range. P. i^. schistacea is the only race regularly occurring in Arizona. Banks (1970) lists three subspceies that nest in Oregon; megarhyncha, fulva and schistacea. He reported megarhyncha and fulva both breeding in one locality. Gabriel son and Jewett (1940) list these races for Oregon; altivagans, unalaschcensis , insularis, sinuosa, annectens, townsendi, fuliginosa, " schi s tac ea , ""rul va , mariposae. B. California distribution of the species Small, (1974) lists P. iliaca as breeding in Klamath Moun- tains, Cascades, Warner Mountains, Sierra Nevada, northern inner Coast Range, higher Basin and Ranges Mountains, Mount Pinos in Ventura County, Transverse and Peninsular Ranges to Mount San Jacinto, Riverside County. Grinnell and Miller (1944): P. i^. sinuosa, "In winter, all sections of the state except areas east of Sierran brushlands; not yet reported in mid-winter from northern humid coastal strip; found in migration in northeastern plateau district." P. i. megarhynchus , "As breeding, Siskiyou Mountains, southern Cascade range, and Sierra Nevada south to Kings River Canyon, Fresno County, and Kearsarge Pass, Inyo County, but exclu- sive of Mono Lake Basin. Summer residents of Trinity Alps of northern Trinity County and southern Siskiyou County and of Siskiyou Mountains are, so far as known in varying degree intermediate toward P. jL. brevicauda. In winter chiefly southern districts west of deserts, from Tehachapi Mountains southward; extends to Santa Cruz and Santa Catalina islands; also occurs commonly northward as far as Shasta County, but not east of Sierra Nevada nor in humid coastal belt north of Marin County." P. i. schistacea, "In winter chiefly southern California west of deserts, But also sparsely north along Sierra Foothills to Tehana County; recorded like- wise from San Francisco Bay region. Migrates along Sierra Nevada and through Modoc and Inyo regions." P. i. monoensis, "Breeds along eastern flank of Sierra Nevada, extending from northern Alpine County south through Mono County to southern rim of Mono Lake Basin. In winter, known from vicinity of Coulterville, Mariposa County, in western foothills of the Sierra and from scattered localities in coastal southern California, including Santa Catalina and San Clemente Islands." P. _i. canescens, "As breeding, White Mountains of Mono and Tnyo Counties, from 8000 fo 9000 feet. In winter, known from Santa Barbara and Los Angeles counties; once recorded from the Colorado River valley." P. i. stephensi, "As breeding, Passerella iliaca (con't.) Pacific drainage of southern Sierra Nevada from southern Fresno County, south of Kings River, south through Tulare County; Mount Pinos in Kern and Ventura counties; and San Gabriel, San Bernardino and San Jacinto Mountains. In winter, detected occasionally in Santa Barbara and Los Angeles Counties in foothills and lower mountains." Dawson (1923): P. i. sinuosa, "Winter resident, apparently well distributed, But no records from southeastern portion of the state." P. i. schistacea, "Scattered records of occur- rence in fall aricl winter in interior and southern California await differentiation from those attributable to P. i. fulva." P. i. megarhyncha, "Winters commonly in the San DTegan dis- trict north to Fort Tejon, Kern County, and west to Santa Barbara." P. i. canescens, "Breeds in the White Mountains of California. Winter range undefined." P. i. monoensis, "Breeds in high transition in Mono Lake region. Winter range unknown." P. i. stephensi, "Breeds in the higher mountains of soutHern California from about latitude 36° in the Sierras. Winter range unknown, presumably the mountains of Lower California." Grinnell (1928) discusses the distribution of the races in lower California. C. California desert distribution Grinnell and Miller (1944): P. i. sinuosa, does not breed. In winter reported in Kern County, Los Angeles County, San Bernardino County, Riverside Valley in San Jacinto Mountains, Riverside County. P. i. schistacea, migrant and winter visitant. Reported in Kern, Los Angeles, San Bernardino, San Diego, Inyo and Riverside Counites. P. i. megarhynchus , breeds in Inyo County. Winter records from Kern, Los Angeles , Riverside, San Diego and San Bernardino Counties. P. i. monoensis, does not breed in the desert. Winter records from Los Angeles, Inyo, Riverside Counties. P. i^. stephensi breeds mostly to the north in California. Winter records from Los Angeles and Kern Counties. Willett (1951) does not list Fox Sparrows in this publication on the birds of the southern California deserts. D. Seasonal variations in distribution AOU (1957), P. i. zaboria, "Winters chiefly east of the Great Plains from eastern Kansas and southern Iowa south to southern Texas, Louisiana, Mississippi, Alabama, and northern Georgia; rarely west to Washington, central and southern California, southern Arizona and Colorado." P. i_. schistacea, "Winters from northern interior California, central Arizona and north- ern New Mexico south through southern California to northern t Passerella iliaca (con't.) Baja California, southern Arizona and western Texas." P. i_. sinuosa, "Winters from southwestern British Columbia south through western Washington, western Oregon and Cal- ifornia to northwestern Baja California." P. ±. canescens, "Winters in southern California, northern Baja California, and southern Arizona." P. i_. megarhyncha, "Winters in low- lands of central and southern California and northwestern Baja California." P. i^. monoensis, "Winters in central interior and southern coastal California and northwestern Baja California." P. i. stephensi, "Winters at lower eleva- tions in southern California. " Stewart et al . (1974) did a study on age ratios of migrating Fox Sparrows in central California. IV HABITAT A. Biotopic affinities Bent et al. (1968), "schistacea seems to prefer willows and rose thickets along the streams in more open country, but in general most abundant close to the foothills of the moun- tains," in Oregon. In Montana the same race prefers "the thickest and most impenetrable willow thickets in the valleys. In northern Nevada. . .common in the Transition Zone, especially on rocky slopes..." megarhynchus inhabits "tracts of Ceanothus cordulatus and manzanita, either in. . . large brush fields or in large clumps... in broken forest. To less extent. . .aspen thickets and stream side willow and alder tangles in the mountains..." Monoensis " prefers brush composed of Manzanita and ceanothus . . . stream side thickets of willow and wildrose and low aspen scrub with associated forbs about springs and meadows." Stephessi "occupies in summer, chin apin and ceanothus brush; less commonly brakes, willow thickets, and gooseberry brushes about moun- tain streams and spring." Grinnell and Miller (1944); sinuosa, "wide variety of chaparral cover or underbush of forest and woodland, but preference is shown for in land areas, and hence the. . .birds occupy semi-arid chaparral of lower Mountain slopes." Schistacea, "inland chaparral, prevailingly of somewhat arid character as with other races that winter in the interior." Megarhynchus , "tracts of ceanothus cordulatus and manzanita. . .aspen thickets and streamside willow and alder tangles in the mountains." monoensis, "in summer brush composed of manzanita and ceanothus ...streamside thickets of willows and wild rose and low aspen scrub. . .about springs and wet meadows." Canescens, "thickets of aspens and birches, with dense ground cover of rose, gooseberry or alder, along streams..." Stephensi, "in summer, chinquapin and ceanothus brush; less commonly brakes, willow | thickets and gooseberry about mountain streams and springs." Passerella iliaca (con't.) B. Altitudinal range • Bent et al. (1968), canescens - above 8,000 feet. Schistacea - breeds in lowlands and at higher altitudes. C. Home range size D. Territory requirements Perch sites - Courtship and mating sites - Nest sites - Bent et al. (1968), "Nest locations are either above ground in the rugged, thorny bushes or sunk in the ground at their bases. Schistacea "prefers to nest in willow thickets, next in dense wild rose bushes. . .Their nests are generally placed some little distance above ground, rarely. . .greater than 3 feet, and are invariably well hidden." Megarhyncha nests were found on the ground near Lake Tahoe and some were 2-3 feet up in Ceanothus bushes. E. Special habitat requirements Oberholser (1974) describes one essential condition for Fox Sparrow breeding; a good supply of dense shrubs for cover. Southwestern racer often find this in Ceanothus. F. Seasonal changes in habitat requirements Peterson (1961): "In winter, woodland under growth, chaparral, parks, gardens." Oberholser (1974) reports Fox Sparrows to inhabit wooded bottomlands along rivers and creeks after migrating south in the fall. V FOOD A. Food preferences Bent et al . (1968) refer to all races eating insects. Gabrielson and Jewett (1940) write that Fox Sparrows feed largely on seeds. Oberholser (1974) lists food items as: ragweed, smartweed, and other seeds, and berries. B. Foraging areas Bent et al . (1968) states that a requirement of all Fox Sparrows is leaf litter in which to forage. Gabrielson and Jewett (1940): "They feed largely on the ground." * ^ Passerella iliaca (con't.) C. Foraging strategies Robbins et al. (1966): "It feeds by scratching, towhee- fashion, with both feet." Gabrielson and Jewett (1940) write that they feed by scratching vigorously on the ground to uncover seeds. D. Feeding phenology E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Martin (1977) states that song appears to function more as a distant threat. Close threats consisted of "chirping calls" and posturing, followed by vigorous winging after the intruder is driven away. t C. Courtship and mating behavior Martin (1977) describes males as being extremely vociferous and singing throughout spring and summer. Females may, at times, produce song but softer and more imcomplete. The messages encoded in the songs are believed to be sex, location, possession of territory, aggressive and sexual, individual identity. D. Nesting phenology E. Length of incubation period Bent et al. (1968), schistacea - 12 to 14 days. F. Length of nestling period G. Growth rates H. Post-breeding behavior VII POPULATION PARAMETERS A. Clutch size Peterson (1961) - 4 to 5. Gabrielson and Jewett (1940) - 3 to 4. A B. Fledging success 10 Passerella iliaca (con't.) C. Mortality rates per age class D. Longevity Kennard (1975) in a study of band returns found the oldest recorded Fox Sparrow to be 9 years, 9 months. E. Seasonal abundance F. Habitat density figures Fill INTERSPECIFIC INTERACTIONS A. Predation B. Competition C. Parasitism Friedmann (1963), "Fox Sparrow is an infrequent victim of the Brown-headed Cowbird. Only in one place has anyone considered it a common host... in Montana. IX STATUS A. Past population trends Wolf son (1955) reports finding Fox Sparrows in Pleistocene deposits in California. B. Present population status Hayward et al . (1976) note a decline in the population of Fox Sparrows in Utah from the 1920 ' s and 30' s. C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status 11 Passerella iliaca (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union. Baltimore, Maryland. 691 pp. Baird, S. F. , T. M. Brewer and R. Ridgway. 1905. A history of North American land birds. Vol. II. Little, Brown, and Co. , Boston. Banks, R. C. 1970. The Fox Sparrow on the west slope of the Oregon Cascades. Condor 72:369-370. Bent, A. C. and collaborators. 1968. Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows and allies. Part three. Smithsonian Inst. U.S. Natl. Mus. Bui. No. 237. Dawson, W. L. 1923. The birds of California. Vol. 1. South Moulton Co., San Francisco Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bui. 233. | Gabrielson, I„ N. and S. G. Jewett. 1940. Birds of Oregon. " Oregon State College, Corvallis. 650 pp. Grinnell, J. 1928. A distributional summation of the ornith- ology of lower California. Univ. Calif. Publ. Zool. Vol. 32. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna. No. 27. 608 pp. Hayward, C. L. , C. Cottam, A. M. Woodbury and H. H. Frost. 1976. Birds of Utah. Great Basin Naturalist Memoirs, No. 1. Hines, J. Q. 1963. Birds of the Noatak River, Alaska. Condor 65:410-425. Kennard, J. H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. Linsdale, J. M. 1928. The species and subspecies of the fringillid genus Passerella Swainson. Condor 30:349-351. Martin, D. J. 1977. Songs of the Fox Sparrow. I. Structure of song and its comparison with song in other Emberizidae. Condor 79:209-221. | Mayr, E. and L. L. Short. 1970. Species taxa of North American F birds. Publ. Nuttal Ornithol. Club 9:1-127. 12 Passerella iliaca (con't.) Oberholser, H. C. 1974. The bird life of Texas. Vol. 2. Univ. of Texas Press, Austin. Parkes, K. C. 1954. Notes on some birds of the Adirondack and Catskill mountains, New York. Ann. Carnegie Mus. 33:149-178. Paynter, R. A. 1964. Generic limits of Zonotrichia. Condor 66:277-281. Peterson, R. T. 1961. A field guide to western birds. Houghton Mifflin Co., Boston. 366 pp. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. of Ariz. Press, Tucson. 212 pp. Ridgway, R. 1915. A manual of North American birds. Fourth Edition. J. B. Lippincott Co., Philadelphia. 653 pp. Robbins, C. S., B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Stewart, R. M. , L. R. Mewaldt and S. Kaiser. 1974. Age ratios of coastal and inland fall migrant passerines in central California. Bird-Banding 45:46-57. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. Wolfson, A., Ed. 1955. Recent studies in avian biology. Univ. of 111. Press, Urbana. 479 pp. * GRAY FLYCATCHER Empidonax wrightii I TAXONOMY A. Type description Empidonax wrightii - AOU (1957) Baird, in Baird, Cassin, and Lawrence, Rep. Expl. and Surv. R. R. Pacific, vol. 9, 1858, p. 200. (El Paso, Texas.) B. Current systematic treatments AOU (1957) describes the Gray Flycatcher as a member of the avian Order Pas serif ormes, Suborder Tyranni, Superfamily Tyrannoidea, and Family Tyrannidae; this species is mono- typic. This species was called Empidonax griseus in the fourth edition of the AOU Check-list (1931), while the name E. wrightii was used for the Dusky Flycatcher, which is called E. oberholseri in the fifth edition. Hellmayr (1927) felt that E. wrightii, E. griseus, E. pulverius, E. fulvipectus, and E. trepidus were alT races of tHe same species; did not want to employ trinominals- until more breeding information was gathered. He called E. griseus the "Gray Flycatcher," and E. wrightii the "Wright's Fly- catcher." Johnson (1963) concluded that griseus is synonymous with wrightii, with the former being dropped from useage. He stated that a complex and sometimes bewildering nomenclature has surrounded these flycatchers. For years, wrightii and oberholseri were considered the same species (E. obscurus) . C. Synonomies of scientific nomenclature Hellmayr (1927) gives Empidonax obscurus. Grinnell and Miller (1944) add E. canescens. D. Synonomies of vernacular nomenclature Hellmayr (1927), Wright's Flycatcher. Dawson (1923) adds Little Gray Flycatcher. II DESCRIPTION A. External morphology of adults Ridgway (1907) gives detailed description of plumages; | above plain olive, tail deep grayish brown, two distinct " wing bands, lower mandible pale, iris brown, legs and feet Empidonax wrightii (con't.) brownish black, has a dull white eye ring. Peterson (1961), "...the lower mandible is more abruptly flesh-colored and ...the back is gray with scarcely a hint of olive or brown." Johnson (1963) gives a detailed description of plumages, molts, and age determination in Gray Flycatchers. Russell and Woodbury (1941), "The long narrow bill, almost com- pletely yellow mandible, nearly completely white belly, and the... almost obsolete eye ring help in identification." B. External morphology of subadult age classes "Young essentially like adults, but wing bands more buffy ...and under parts more whitish" (Ridgway 1907). Johnson (1963) discussed methods of age determination in this species; "the tips of the juvenile rectrices in wrightii differ in shape from those of the adult in being pointed or rounded." Russell and Woodbury (1941) found that, "In young birds... the white outer web of the outer tail feathers is distinctive." C. Distinguishing characteristics Interspecific - Hellmayr (1907), "Similar to E. hammondii, but... bill much longer, and coloration of anterior under ^^ parts paler." Peterson (1961) states that this species is similar to Dusky and Hammond Flycatchers. . .can be safely identified on the breeding grounds by habitat." Phillips et al. (1964) describes methods of distinguishing this species from other small f lycatchers--"This species does not jerk the tail, but dips it slowly and evenly downward ...This in combination with its white wing-bars, pale gray color, and frequent occurrence in open country, makes identification possible in the field." Intraspecific - Ridgway (1907), sexes alike; adult male-- length 129 mm; wing 69.5 mm; tail 62.6 mm and adult female-- length 130 mm; wing 67.4 mm; tail 60.6 mm. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species A0U (1957), range of species "Breeds from central Oregon, southwestern Idaho, southwestern Wyoming, northeastern Utah, and central Colorado, south to central eastern Calif- ornia (Inyo Mountains), southern Nevada, central Arizona, and central western New Mexico." Hellmayr (1927) gives range of E. wrightii as "Western United States, breeding from soutHern British Columbia and southwestern Saskatchewan south to southern California (San Gabriel, San Bernardino, San Jacinto, and Santa Rosa Mountains), Arizona, New Mexico, and western Texas, and east to eastern base of Rocky Moun- tains, wintering from northern to southern Mexico." • Empidonax wrightii (con't.) B. California distribution of the species Grinnell and Miller (1944) gives the California distribu- tion of the Gray Flycatcher as "In general, as breeding, higher Mountain masses of the State; at north, from Warner Mountains, Modoc County, west through Shasta, Siskiyou and Trinity regions as far as south Fork Mountain, on Trinity-Humboldt county line... south from Mount Shasta... over entire Sierra Nevada to their southern terminus near Tulare-Kern County line; to eastward, on White Mountains, in Mono and Inyo counties; recurs on various isolated, higher ranges of southern California; Mount Pinos, San Gabriel, San Bernardino, San Jacinto, and Santa Rosa moun- tains." Small (1974) lists this species California range as "breeds in northeastern Basin and Ranges Region from Modoc County south to Inyo County; some of population winters in southern California." Willett (1933) describes this species as a summer resident of upper Transition and Boreal zones of mountains, south to San Jacinto and Santa Rosa ranges. C. California desert distribution Grinnell and Miller (1944) list records of transient Gray Flycatchers, which include--Death Valley (26 April); near Needles, San Bernardino Co. (19 February); Palm Springs and Cottonwood Springs, Riverside County (April). Johnson et al, (1948) found Gray Flycatchers only as late spring migrants in the Providence Mountains. Grinnell (1914) collected a male Gray Flycatcher near Needles (lower Colorado River Valley) on 19 February; he seldom saw the species in this area. Wauer (1964) found Gray Flycatchers breeding in the pinon- juniper woodlands of the Panamint Mountains in Death Valley (5,000-6,000 feet elevation). Van Rossem (1922) states that the Gray Flycatcher, after passing through the San Diegan district on spring migration, breeds in the desert mountain ranges of California (lists several speci- mens taken in the White Mountains, Mono and Inyo counties). Van Rossem (1911) noted Gray Flycatchers wintering near the Sal ton Sea (January-March). Miller and Stebbins (1964) called this species a spring migrant (only) in Joshua Tree National Monument. Willett (1951) found Gray Flycatchers migrating and wintering on the deserts of southern Calif- ornia. Hollister (1908) noted a single Gray Flycatcher near Needles in April in a study of the birds of that region, D. Seasonal variations in distribution A0U (1957) states that Gray Flycatchers migrate, in winter, to southern California (Ventura, Needles), central Arizona, southern Coahuila, and central Tamaulipas south to southern Empidonax wrightii (con't.) Baja California, Jalisco, Michoacan--in migration to western Texas. In California, Grinnell and Miller (1944) give the seasonal status of this species as "on breeding ground, summer resident, April to September. . .elsewhere, a spring transient, sparse; in autumn apparently passes over the southward lowlands nearby or quite unobserved." Small (1974) described seasonal status as "transient and summer resident, April to October." Bent (1963) stated that Gray Flycatchers are found north to southern California and south to Central America during winter. He gives date of fall departure (for much of California population) as 5 November, and early April as date of spring arrive!. IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), "Most characteristic, green chaparral with trees scattered through it; in other words, mixed brushland and trees, either deciduous or coniferous ones... green manzanita and chinquapin, with scrub black- oaks, or scattering red or white firs, or lodgpole pines, or Jeffery pines. .. there is no apparent attraction to water." Small (1974) gives breeding habitat in California as "pinon- juniper woodland, mixed Great Basin sagebrush and pines, arid forests." Van Rossem (1936) found that the summer distribution of Gray Flycatchers in Nevada closely coincides in altitude with that of the yellow pine. In Arizona, Swarth (1904) found this species most abundant below 5000 feet, favoring the foothill regions covered with scrub oak, madrona, and manzanita. Grinnell and Swarth (1913) found Gray Flycatchers breeding between the lowest edge of the Transition Zone up to the higher slopes of the San Jacinto Mountains of California. Johnson (1965) found these flycatchers in "pinon-juniper where scattered ponderosa pine and clumps of mountain mohogany were subdominant" (breeding) . B. Altitudinal range Grinnell and Miller (1944) give altitudes of occurrence in California as from 4,000 to 11,300 feet. Van Rossem (1936) notes the regular occurrence of this species from 7,500 to 10,000 feet in Nevada. Willett (1933) found two species from 5,500 to 9,000 feet in California. Johnson et al. (1948) found Gray Flycatchers between 5,000 and 6,400 feet during spring migration (May) in the Providence Mountains, California. Grinnell (1908) noted this species breeding at 10,000 feet in Mono County, California. £ I ♦ Empidonax wrightii (con't.) C. Home range size Russell and Woodbury (1941) found that during the breeding season, Gray Flycatchers usually stayed within 100 yards of the nest tree. D. Territory requirements Perch sites - Hoffmann (1924) noted Gray Flycatchers singing from small pines in dry, open woodland of Oregon. Bent (1963) recounts the use of small twigs as perch sites while feeding. Courtship and mating sites - Johnson (1963) describes court- ship sites as "the male on a horizontally placed branch 5-20 feet above the ground. The female perches nearby." Nest sites - Dawson (1923), "placed in upright crotch in bushes, or settled upon branch of evergreen sapling." Grinnell (1908) gave an average nest height of 7.5 feet in the San Bernardino Mountains. Nest sites included willow, Cottonwood, black oak, incense cedar, tamarack pine, fir, buckthorn, manzanita, and mountain mahogany; nest heights ranged from 2 to 40 feet. Johnson (1963;, "the nests of this species are often placed on horizontal branches of trees as high as 20 feet above the ground (mean height of 17 nests, 12.5 feet)." Walker (1914) found Gray Flycatchers nesting in sagebrush in Oregon. E. Special habitat requirements Grinnell and Miller (1944), "The essential elements appear to be low-growing thickets for nesting and much of the foraging, and near by high singing posts and lookout stations." Grinnell (1908) found this species was confined to the less arid parts of the San Bernardino Mountains, but were not dependent upon a nearby water source for breeding. In southern Nevada, Johnson (1965) found that considerable open ground characteristically occurred on occupied terri- tories of this species. F. Seasonal changes in habitat requirements Peterson (1961), "Breeds in sagebrush, pinon, junipers. In winter, willow thickets, brush." In winter, Small (1974) states that Gray Flycatchers move into riparian woodlands from their woodland and sagebrush breeding grounds. Russell and Woodbury (1941) state that after nesting, Gray Flycatchers move into sagebrush habitat (August and later). Empidonax wrightii (con't.) V FOOD A. Food preferences Russell and Woodbury (1941) found that in Arizona and Utah, the food consisted entirely of insects. It varied in size from tiny beetles to large butterflies, and included grass- hoppers, wasps, moths, and ant-lions. B. Foraging areas In the San Bernardino Mountains of California, Grinnell (1908) found Gray Flycatchers foraging from willow thickets of canyon bottoms, all the way up into the upper reaches of tall pines. Hollister (1908) noted a Gray Flycatcher feeding 'among the higher creosote bushes along a dry wash" during April near Needles, California. C. Foraging strategies Oberholser (1974) states that in Texas "It frequently perches atop a bush or low tree from where it flycatches." Salt (1953) lists the Gray Flycatcher as a member of the "air" foraging guild. Bent (1963) recounts the taking of insects from beneath leaves of trees. D. Feeding phenology Bent (1963) stated that very little information is available on food habits and phenology, which "probably does not differ materially from that of other western Empidonaces. " E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Oberholser (1974), "Song on the breeding territory is vigorous..." Johnson (1963) stated that males of wrightii defend territories both intra- and interspecifically. In disputes between wrightii and oberholseii, the former was usually the dominant bird. C. Courtship and mating behavior Wheelock (1944) describes courtship, which lasts for about 2 weeks before nest-building begins. Grinnell (1908) des- cribes the singing of this species during breeding ^^ Empidonax wrightii (con't.) "jumble of twitters, with rising and falling inflection... which reminded me of... the Black Phoebe." Johnson (1963) gave a detailed account of courtship and mating behavior, which includes a male solicitation display, a female soli- citation display (wing- fluttering prior to copulation), and extensive flight songs. D. Nesting phenology Wheelock (1904) gives California breeding season as 15 June to 15 July. Russell and Woodbury (1941) found that 2 broods are usually raised in a season (Utah and Arizona); nesting season extends from mid-May until August. Bent (1963) gives California egg dates as: 65 records, 27 May to 18 July; 33 records, 14 June to 24 June, indicating the height of season. E. Length of incubation period Dawson (1923) gives a 13 day incubation period. Wheelock (1904) states that incubation is shared by both adults, and lasts 13-14 days. Johnson (1963) found the incubation period of wrightii to be 14 or 15 days, with the female performing all duties of incubation. Russell and Woodbury (1941) list a 14 day incubation. F. Length of nestling period Wheelock (1904) states that young are ready to leave the nest after about 2 weeks from hatching. Russell and Wood- bury (1941) found that young usually fledge in 16 days; young are then fed an additional 14 days after fledging by their parents. G. Growth rates Wheelock (1904) found that young are fed by regurgitation for the first few days after hatching. Russell and Wood- bury (1941) reported that at one week of age, nestlings are about one- third grown and that major feather development has begun. They found that the feathers were near complete growth by 11 days of age. H. Post-breeding behavior Following breeding, much of the California population of Gray Flycatcher migrates to Mexico (Bent 1963); birds do winter in southern California. Empidonax wrightii (con't.) II POPULATION PARAMETERS A. Clutch size Peterson (1961), "Eggs (3-4) white." Wheelock (1940) lists a clutch size of 3-5 eggs. Bent (1963) gives an average clutch as 3 or 4 eggs, sometimes 2. B. Fledging success Johnson (1963), "The fates of 25 eggs from. . .nine nests were as follows: 12 hatched, 10 stolen by predators, and 3 infertile" (California). C. Mortality rates per age class Bent (1963) reported that "There is a high mortality among the young... due to sudden and severe wind and storms during the nesting season." D. Longevity E. Seasonal abundance Peterson (1961) called the Gray Flycatcher a "sparse" winter visitor in southern California. Grinnell and Miller (1944), "On breeding ground. . .common, even abundant for a flycatcher, Elsewhere, a spring transient, sparse." F. Habitat density figures Wheelock (1904) reports finding 4 nests within a radius of a quarter mile or less in California pine forest. Willett (1933) calls this species "most plentiful between 6,500 and 9,000 feet" in California. Grinnell (1908) stated that there were "not less than 3760 Gray Flycatchers in the San Barnardino Mountains" during breeding season; called their abundance "remarkable." About 8 breeding territories of Gray Flycatchers were found in an 800 x 600 yard plot in Nevada Co., California; the area was dominated by sagebrush and scattered yellow pine (data calculated from Johnson 1963). Haislip (in Friedmann et al . 1977) found a breeding population of about 25 pairs per 100 hectares in Oregon. a Empidonax wrightii (con't.) VIII INTERSPECIFIC INTERACTIONS A. Predation Grinnell (1908) felt that chipmunks and jays destroyed nests in the San Bernardino Mountains. Pierce (1916) also noted the taking of eggs by chipmunks in these mountains. Bent (1963) recounts the destruction of eggs by chipmunks, snakes, weasels, and other predators. B. Competition Johnson et al. (1948) found that Gray and Hammond flycatchers occupy the same habitat (pinon- juniper) during spring migra- tion in the Providence Mountains of California. In areas of sympatry, Johnson (1963) concluded that Gray and Dusky (E. oberholseri) flycatchers avoided direct competition tKrough ecological separation (different foraging and nest- ing sites). Beaver and Baldwin (1975) feel, however, that "It remains to be demonstrated that competition for food between E. wrightii and E. oberholseri is eliminated by habitat cTif terences when in sympatry." C. Parasitism Friedmann et al. (1977), in recounting the first published records for this species as a cowbird host--"It appears that the Gray Flycatcher is a regular host choice of the Brown-headed Cowbird in central Oregon, and probably is more affected elsewhere than the absence of published records would indicate." They noted that 20 to 30% of Gray Fly- catcher nests were parasitized in an Oregon study. IX STATUS A. Past population trends Grinnell (1908) found this species to be very abundant as a breeder in the San Bernardino Mountains. In the San Jacinto Mountains, Grinnell and Swarth (1913) called Gray Flycatchers "abundant breeders." B. Present population status Johnson and Garrett (1974), "A major recent southwestward extension of breeding range in California, into formerly unoccupied woodland of mature single-leaf pinyon. . .from. . . Tulare County, and from Clark Mountain, eastern San Bernar- dino County." • • 10 Empidonax wrightii (con't.) C. Population limiting factors Bent (1963) felt that the Gray Flycatcher is "confined mainly to the foothills and slopes of the various mountain ranges, at elevations varying with latitude." D. Environmental quality: adverse impacts E. Potential for endangered status 11 Empidonax wrightii (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. 5th edition. American Ornithologists' Union, Baltimore, MD. 691 pp. Beaver, D. L. and P. H. Baldwin. 1975. Ecological overlap and the problems of competition and sympatry in the Western and Hammond's flycatchers. Condor 77:1-13. Bent, A. C. 1942. Life histories of North American flycatchers, larks, swallows, and their allies. U.S. Nat. Mus. Bull. 179:1-555. Dawson, W. L. 1923. The birds of California. Vol. 2. South Moulton Co., San Francisco. Dickey, D. R. and A. J. Van Rossem. 1922. The Gray Flycatcher in the White Mountains of California. Condor 24:137. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the parasitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Grinnell, J. 1908. The biota of the San Bernardino Mountains. Univ. California Publ. Zool. 5:1-170. Grinnell, J. 1914. An account of the mammals -and birds of the lower Colorado Valley. Univ. California Publ. Zool. 12: 51-294. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp. Grinnell, J. and H. S. Swarth. 1913. An account of the birds and mammals of the San Jacinto area of southern California. Univ. California Publ. Zool. 10:197-406. Hellmayr, C. E. 1927. Catalogue of birds of the Americas and the adjacent islands. Part 5. Field Mus. Nat. Hist. Zool. Ser. Publ. 242, Vol. 13. Hoffmann, R. 1924. Song of the Gray Flycatcher. Condor. 26:195 Hollister, N. 1908. Birds of the region about Needles, Cal- ifornia. Auk 25:455-462. Johnson, N. K. 1963. Biosystematics of sibling species of flycatchers in the Empidonax hammondii-oberholseri-wrightii complex. Univ. California Publ. Zool. 66: 79-238. 12 Empidonax wrightii (con't.) Johnson, N. K. 1965. The breeding avifaunas of the Sheep and Spring ranges in southern Nevada. Condor 67:93-124. Johnson, D. H. , M. D. Bryant and A. H. Miller. 1948. Verte- brate animals of the Providence Mountains area of California. Univ. California Publ. Zool. 48:221-376. Johnson, N. K. and K. L. Garrett. 1974. Interior bird species expand breeding ranges into southern California. Western Birds 5:45-56. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Moore, R. T. 1940. Notes on middle American Empidonaces. Auk 57:349-389. Oberholser, H. C. 1920. Empidonax griseus in Nevada. Auk 37:133. Oberholser, H. C. 1974. The bird life of Texas. Vol. 2. Univ. Texas Press, Austin. Peterson, R. T. 1961. A field guide to western birds. Houghton Mifflin Co., Boston. 366 pp. Phillips, A. R. 1939. The type of Empidonax wrightii. Auk 56:311-312. Phillips, A. R. 1944. Some differences between Wright's and Gray Flycatchers. Auk 61:293-294. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. 212 pp. Pierce, W. M. 1916. More bird notes from Big Bear Valley, San Bernardino Mountains. Condor 18:177-182. Ridgway, R. 1907. The birds of North and Middle America. Part 4. Bull. U.S. Nat. Mus. No. 50. Rowley, J. S. 1939. Breeding birds of Mono County, California. Condor 41:247-254. Russell, H. N., Jr. and A. M. Woodbury. Nesting of the Gray Flycatcher. Auk 58:28-37. Salt, G. W. 1953. An ecological analysis of three California avifaunas. Condor 55:258-273. 13 Empidonax wrightii (con't.) Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Swarth, H. S. 1904. Birds of the Huachuca Mountains, Arizona. Pacific Coast Avifauna No. 4. 70 pp. Swarth, H. S. 1924. Notes upon certain summer occurrences of the Gray Flycatcher. Condor 26:195-197. Van Rossem, A. 1911. Winter birds of the Salton Sea region. Condor 13:129-137. Van Rossem, A. J. 1936. Birds of the Charleston Mountains, Nevada. Pacific Coast Avifauna No. 24. 65 pp. Walker, A. 1914. Nesting of the Gray Flycatcher in Oregon. Condor 16:94. Wauer, R. H. 1962. A survey of the birds of Death Valley. Condor 64:220-233. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Wheelock, I. G. 1904. Birds of California. A. C. McClurg and Co. , Chicago. 578 pp. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. Yaich, J. A. and E. J. Larrison. 1973. Nesting record and behavioral observations on the Gray Flycatcher in Washing- ton. Murrelet 54:14-16. GREAT HORNED OWL Bubo virginianus I TAXONOMY A. Type description AOU (1957) B. v. pacificus Cassin, Illustr. Birds California, Texas, etc., pt. 6, (Sept. 12) 1854, p. 178. (The West - Sacramento, California.) B. v. pallescens Stone, Amer. Nat., 31, no. 363, Mar. 1, 1897, p. 237. ("Watson Ranch, 18 miles southwest of San Antonio , Texas . ) B. Current systematic treatments Peters (1940), recognizes eleven species in the genus Bubo; sixteen subspecies of the species virginianus. Order: Strigiformes; Family: Strigidae. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), B. y. pacificus: Strix virginiana; Bubo magelannicus ; B. y. arcticus; B. y. subarcticus; B. subarcticus; Asio magellanicus ; A. m. pacificus; A."""m. icelus; B. y. icelus; Bubo horriEilis; B. y. elacKistus. B. y. pallescens: B. y. subarcticus; B. y. pacificus; Asio magellanicus pallescens. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), B. y. pacificus: Pacific Horned Owl; Western Great Horned Owl; Western Horned Owl; Horned Owl; Dusky Horned Owl; California Horned Owl. B. y. pallescens Western Horned Owl; Pacific Horned Owl; Desert Horned Owl. II DESCRIPTION A. External morphology of adults Ridgway (1914), detailed description of adults and young of B. v. virginianus and comparisons with pallescens and pacificus, including plumage, soft parts! and measurements. Peterson (1961), "the only large N. American owl with ear tufts, or 'horns. ' Heavily barred beneath; conspicuous white throat-collar. In flight, as large as our largest hawks; dark (most races), looks neckless, large-headed." Dawson (1923), B. y. pacificus: "Adult: Ear tufts conspi- cuous, two inches or more m length, black, bordered with I ochraceous; entire upperparts dusky or blackish, finely barred and mottled with prevailing whitish and ochraceous, Bubo virginianus (con't.) the latter color predominant on each feather basally; wing- quills and tail faintly broad-barred; facial disc ochraceous, sharply bordered by blackish laterally, feathers whitish and black-tipped centrally, borders before and over eye blackish; a broad white space on chest; feathers of remaining under- parts tawny or ochraceous tawny at base, changing to white on terminal portions (in very variable amount;, finely and heavily barred with dusky brown; the sides of breast spotted with the same color; the toes pale tawny, nearly immaculate; iris bright yellow. Bill and toe-nails bluish black." B. y. pallescens: "Similar to B. y. pacificus, but much paler, the ochraceous tawny element largely replaced by white, sometimes nearly wanting below, the barring of underparts usually narrower and finer." B. External morphology of subadult age classes Ridgway (1914), detailed description of plumage and soft parts. Dawson (1923), "Young: Above and below ochraceous, barred with dusky. Chicks are covered with white down." C. Distinguishing characteristics Interspecific - Peterson (1961), "Long-eared Owl is much smaller. . .with lengthwise, streakings, rather than cross- wise barrings, beneath. 'Ears' closer together." Intraspecific - Ridgway (1914), B. y. pacificus: "Similar to B. y. pallescens but darker throughout, the feet more heavily mottled with dusky, the face usually with more decided tinge or suffusion of tawny; slightly smaller." II GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), "America, exclusive of West Indies, from the limit of trees in the Arctic to the Straits of Magellan." B. y. pacificus: "California west of Great Basin and desert areas (exclusive of northern humid coast belt) south to lat. 30° N. in northwestern Baja California and east to extreme western central Nevada (Tahoe area)." B. y. pallescens "Arid regions of southeastern California (from Inyo district) , southern Nevada (Clark County), southern Utah (Virgin River), northern New Mexico, and north-central Texas south to extreme northeastern Baja California, northern Sonora (Hermosillo) , Chihuahua, Durango, Coahuila, Nuevo Leon, and northern Tamaulipas. " • • f Bubo virginianus (con't.) B. California distribution of the species Grinnell and Miller (1944), B. v. pacificus: "In general, that major portion of State lying west of the Great Basin and southeastern deserts, and east of the northern and central humid coast belt; north from Mexican line in San Diego County to Oregon line in central Siskiyou County; at extreme north, specimens of this race at hand... from South Fork Mountain and Weaverville, Trinity County, and from Boggs Creek and near Weed, Siskiyou County. Range includes all of Sierra Nevada, Great Central Valley and enclosing foothills, and southern coast range belt northwest on the seacoast through Monterey County and interiorly to Alameda and Contra Costa counties." B. y. pallescens: "In general, Colorado and Mohave deserts. North from Mexican line in Imperial County to Argus and Panamint Mountains, in Inyo County... and even, apparently, to Benton, Mono County... West from valley of Colorado River, Needles to Pilot Knob. . . to south end of Sal ton Sea, Imperial County... and to Victor- ville, San Bernardino County." Dawson (1923), B. v. pacificus "(chiefly contained within California). — California, except the southeastern portion, the humid coastal strip (narrowly) north of Latitude 35, and (possibly) the extreme northeastern portion, north into south-central Oregon, east to San Fran- cisco Mountains, Arizona, south to northern Lower California." B. y. pallescens: "Resident along the Colorado River, in the Imperial Valley, and in wooded portions of the Colorado and Mohave Deserts, To a limited degree also in the desert ranges." C. California desert distribution Grinnell and Miller (1944), B. y. pacificus: reported from Escondido and Sorrento, San Diego County. B. y. pallescens: reported from Death Valley; Yermo and Twentynine Palms, San Bernardino County; San Fernando, Pasadena, and San Antonio Canyon, Los Angeles County; Buena Vista Lake, Kern County. Also, "west from valley of Colorado River, Needles to Pine Knob... to south end of Salton Sea, Imperial County... and to Victorville, San Bernardino County." D. Seasonal variations in distribution AOU (1957), no seasonal variations noted. IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), B. y. pacificus: "Of wide variety; perhaps most usual, woodland especially of oaks, or broken type of forest, with open ground included or adjacent. But Bubo virginianus (con't.) also, cliff- sided canyons; broad washes if with trees such as cottonwood and sycamore containing old hawks' nests; in fact, almost any locality affording sheltered daytime roosting places and nesting sites up from the level ground, whether in trees or in rock walls." B. v. pallescens: "In different places: rock-walled canyons; pmon- and juniper- clothed mountain sides; riparian lowlands where grow cotton- woods and willows of large size; desert washes with bluff - like sides; desert mesas supporting large-sized tree-yuccas." Small (1974), "broken woodland of oaks or coniferous-deciduous forest, thickly-wooded canyons, desert, riparian woodland." Miller (1951), Upper and Lower Sonoran, Transition and Canadian life zones. B. Altitidinal range Grinnell and Miller (1944), B. y. pacificus: "occurs from near sea level up regularly, at least m summer, to 7000 feet, exceptionally to 10,500 feet." B. y. pallescens: "from 200 or more feet below sea level, in Death Valley and around Salton Sea, up to at least 6200 feet, in Pana- mint Mountains, Inyo County." C. Home range size Fitch (1947) "Several times a pair was seen at dusk making a flight of a quarter of a mile or more across open fields to hunt on a wooded ridge opposite the one where they had roosted for the day." Baumgartner (1939), concerning birds in New York: "In no case did the size of the feeding range have a radius exceeding one- fourth of a mile in any direc- tion from the nest, but obviously the individual character- istics of the topography and the availability of food in the immediate vicinity are important factors determining the range." Craighead and Craighead (1956), report ranges of four nesting pairs in Wyoming, 1947: 0.62 sq. mi. (1.8 mi. max. diam.); 0.45 sq. mi. (1.4 mi. max. diam. ) ; 1.10 sq. mi. (1.6 mi. max. diam.); 1.11 sq. mi. (1.6 mi. max. diam. ) . D. Territory requirements Perch sites - Cushing (1939), "was seen at night perched upon a telephone pole." Fitch (1947), "Horizontal limbs of larger Digger pines provide perch sites during the night hours of activity. . .The perches used in actual hunting are lower, so that prey may be more readily detected and pur- sued at close range... Such perches atop rock piles. .. fence posts, stumps, and logs." Bent (1938), "A favority perch of the bird is the roof of a building." Courtship and mating sites - • f Bubo virginianus (con't.) Nest sites - Fitch (1947), reports sites of six nests: "25 feet above ground, in depression on top of digger pine stub... 15 feet above ground, on bole of cottonwood growing in stream bed... 45 feet above ground and about 25 feet out on horizontal limb; an old gray squirrel nest taken over... 50 feet above ground in Digger pine, in a shallow depression of trunk where a large limb had broken off. . . 65 feet above ground in crotch of main trunk of Digger pine. . .On ground, sheltered by edge of a large boulder." Dawson (1923), "A cranny or inaccessible ledge of cliff, or a deserted nest of Swainson Hawk, Western Redtail, Yellow-billed Magpie, or Western Crow. . .Rarely in hollow trees." Baumgartner (1938), "In the deserts of the South- west cactus plants take the place of trees and horned owls often occupy old nests among the thorny branches." E. Special habitat requirements Grinnell and Miller (1944), "the requisite elements of the habitat seem to be shaded shelter and places for nesting, out of reach of terrestrial marauders --niches in cliffs, or other birds' nests in trees." F. Seasonal changes in habitat requirements V FOOD A. Food preferences Cunningham (1960), Examination of pellets collected on the U. of California campus, Los Angeles and in the Santa Monica Mountains showed the following prey items: Neotoma fuscipes, Thomomys bottae, Mus musculus , Micro tus calif ornicus, Reithrocfontomys megalotis, Perognathus sp., Dipodomys agilis, Peromyscus sp . , Notiosorex crawfordi, Sylvilagus sp . , Sorex ornatus, Scapanus latimanus , Rattus sp. , and un- identified birds. Fitch (1947), lists remains of mammals, birds, reptiles, amphibians, and invertebrates found in 654 pellets collected in Madera County, California. Craig- head and Craighead (1956), "In 1942 mammals were 40.5 per- cent and birds 59.6 percent of the Horned Owl diet; in 1948 mammals were 62.1 percent and birds 29.7 percent." B. Foraging areas Craighead and Craighead (1956), "Their food is largely crepuscular or nocturnal animals. . .Are present in all types of country that support their prey... The large mature wood- lots which furnished more extensive and perhaps better hunting grounds, and were thus intimately related to food availability. " Bubo virginianus (con't.) C. Foraging strategies Bent (1938), "While this owl usually remains hidden during the day and does most of its hunting at night, it can see well enough to do some by day, if necessary." Rhodes and Duke (1977), examination of gastric motility and pellet for- mation. "The muscular stomach of the Great Horned Owl appears to be the site of initial proteolysis; chemical separation of soft tissues from hair and bone is completed there. . .Gastric motility is also essential for evacuating fluid from the stomach after chemical digestion is complete, and for ferming and egesting the pellet." D. Feeding phenology Craighead and Craighead (1956), "The increased activity of pheasants at the time of dispersion from protective winter roosting areas to crowing territories, when protective cover is at a minimum, made the Ring-necked Pheasant more vulnerable to the Horned Owl at this period. It is signi- ficant that this increased vulnerability of adult Ring- necked Pheasants occurs at a time when other prey popula- tions are at or near a seasonal low." E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Miller (1930), B. y. pacificus: "Bubo hoots from a point within his chosen territory. Within that territory he gen- erally responds quickly to the note of a supposed invader. Calls from without his estates do not bring him to the spot though they may rouse him to send out his own challenge. The male bird is the more aggressive and is recognized by the deeper voice and more regular cadence." Baumgartner (1939), "holds a definite territory throughout the nesting season. .. In many cases the male takes up his station... before the period of courtship and mating begins." C. Courtship and mating behavior Bent (1938), "So little is known of the courtship of these big birds." Baumgartner (1938), "Hooting of the males becomes conspicuous about a month before mating begins. Active courtship and mating apparently last less than two weeks. .. Hooting of the males has a three-fold function--to express physical vigor and vitality; to warn other males of their territorial rights; and to attract a mate... The hooting of the female is chiefly limited to the mating and nesting season." • • • t Bubo virginianus (con't.) D. Nesting phenology- Davis (1933), reports, in Butte County, California, the first date as 8 February; the last date as 1 March; the average date 18 February. Dawson (1923), "February- April; one brood." Baumgartner (1938), reports average dates of completed first sets of eggs throughout the U.S. and Canada. E. Length of incubation period Hoffmeister and Setzer (1947), report 34 to 35 days for four observed. Baumgartner (1938), "normally begins with the laying of the first egg... No indisputable data on the exact length of the incubation period has been found. . . At least twenty-six and probably nearer thirty days." F. Length of nestling period Hoffmeister and Setzer (1947), "By the forty-fifth day, the young owls are able to fly short distances and thus are able to leave the site of the nest permanently. At this time they are about three- fourths grown." I G. Growth rates Hoffmeister and Setzer (1947), regularly recorded weights of 4 developing young (graph included). ' During the first four weeks of postnatal growth, each owl gained in weight, daily, an average of 33-1/3 grams or an increase of 11.1 per cent... From the beginning of the fifth week until the time the young left the nest, the three owls gained on the average only 12.7 grams or approximately 1.6 percent in weight daily." H. Post-breeding behavior Craighead and Craighead (1956), "young of the previous year were a very small proportion of the spring population. As nesting patterns became fixed, immature ... owl s were haras- sed constantly and buffeted from one territory to another. . . Once settled, they developed a range that often was limited by those of other neighbors." Errington (1932), "were apt to station themselves in the fall in the near neighborhood of old stick nests (hawk or crow) which they would appro- priate in the spring." VII POPULATION PARAMETERS A. Clutch size | Fitch (1947), reports three nests with three eggs; also three nests with one, two, and three nestlings. Dawson (1923), "2 or 3, rarely 4; rounded ovate, white, luster- less, granular." Bubo virginianus (con't.) B. Fledging success Craighood and Craighood (1956), report in Michigan 50% (1942) and 27% (1948) fledgling success (fledglings per eggs laid). In Wyoming: nest success was 89% (fledglings per eggs laid) in 1947. C. Mortality rates per age class Craighead and Craighead (1956), report from studies in Michigan: 33% (1942) and 21% (1948) of the clutches were incomplete and nests receiving no eggs; 55% (1948) of the eggs were destroyed, infertile, or failed to hatch; there was 50% (1942) and 40% (1948) mortality in the nest after hatching. In Wyoming in 1947: 25%, of the clutches were incomplete or nests failed to receive eggs; 11% of the eggs were destroyed, infertile, or failed to hatch; no mortality of nestlings was observed. D. Longevity Kennard (1975) reports a record age of 12 years, 8 months in 1939. Age and sex unknown when banded in 1927. E. Seasonal abundance ^P Baungartner (1939), reports observed nesting populations (one to three pairs per square mile) with winter populations seemingly equally dense, since he observed that resident birds generally remain in the nesting vicinity throughout most of the year. F. Habitat density figures Franzreb (1975), reports 14.3 breeding pairs per 100 hectares at Thomas Creek, White Mountains, Arizona, summer, 1973. Fitch (1947), reports census of individuals in 2000 acre area, Madera County, California. Seven counts from 1938 to 1947 revealed from 14 to 25 individuals. Baumgartner (1939), "In optimum range the decided territorial require- ments of the males probably determine the nesting density. Populations in such areas seem to average from one to three pairs of nesting owls to the square mile. Over most of the range of the species the nesting density is much lighter." m Bubo virginianus (con't.) VIII INTERSPECIFIC INTERACTIONS A. Predation Hoechlin (1976), reports the remains of two adults at one nest of the California Golden Eagle. Miller (1952), re- corded the reactions of a number of species (prospective prey) to imitated hoots of this owl. Killpack (1951), found the following remains in a nest in Uintah County, Utah: Short-eared Owl, young muskrat, adult jackrabbit, Ring-necked Pheasant, Black-billed Magpie, Morning Dove, domestic pigeon, American Coot. Placed emphasis upon large size of these items. Fox (1948), reports a young owl of this species feeding on a garter snake (Thamnophis sirtalis inf ernalis) . Carnie (1954) reports remains of seven indivi- duals in nests of Golden Eagles, 1947-1952, in central California. Wiley (1975), reports predation on young Red- shoulder Hawks. B. Competition • • Wiley (1975), discusses interactions between this species and other raptors nesting in close proximity with Horned Owls. Cooper's Hawks vigorously attacked the adult owls. Red- shoulder Hawks were not observed to attack the owls, but the young hawks were preyed upon. American Kestrels regularly attacked the owls. "A pair of Cooper's Hawks, Accipiter cooperi, attempted to use a Great Horned Owl nest after the owl nest had failed. The owl began nesting activity in a stick nest that Cooper's Hawks had built the previous year." C. Parasitism Fitch (1947), reports the half-grown young in one nest were attacked by small blood -sucking flies (Eusimulium clarum) . IX STATUS A. Past population trends B. Present population status Small (1974), "resident." C. Population limiting factors Baumgartner (1939), "Horned Owl populations are limited chiefly by human molestation and man-made changes in their environment that result in a scarcity of cover and less 10 3ubo virginianus (con't.) ^A frequently a lack of nesting sites and sufficient food." Craighead and Craighead (1956), "Lack of extensive wooded areas, rather than food supply, apparently was the factor limiting the Horned Owl population." D. Environmental quality: adverse impacts E. Potential for endangered status • 11 A Bubo virgin! anus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Baumgartner, F. M. 1938. Courtship and nesting of the Great Horned Owls. Wilson Bull. 50:274-285. Baumgartner, F. M. 1939. Territory and population in the Great Horned Owl. Auk 56:274-282. Bent, A. C. 1938. Life histories of North American birds of prey. Part 2. Bull. U.S. Nat. Mus. No. 170. Carnie, S. K. 1954. Food habits of nesting Golden Eagles in the coast ranges of California. Condor 56:3-12. Craighead, J. J. and F. C. Craighead, Jr. 1956. Hawks, Owls and Wildlife. Stackpole Co., Pennsylvania. Cushing, J. E. , Jr. 1939. The relation of some observations upon predation to theories of protective coloration. Condor 41:100-111. # Cunningham, J. D. 1960. Food habits of the Horned and Barn Owls. Condor 62:222. Davis, W. B. 1933. The span of the nesting season of birds in Butte County, California, in relation to their food. Condor 35:151-154. Dawson, W. L. 1923. The birds of California. South Moulton Co. , San Francisco. Errington, P. L. 1932. Studies on the behavior of the Great Horned Owl. Wilson Bull. 44:212-220. Fitch, H. S. 1947. Predation by owls in the Sierran foothills of California. Condor 49:137-151. Fox, W. 1948. Horned Owl feeding on Garter Snake. Condor 50:46. Franzreb, K. E. 1975. Avian densities in a mixed-coniferous forest, Thomas Creek, White Mountains, Arizona. Western Birds 6:101-105. Grinnell, J. and A. H. Miller. 1944. The distribution of the ^ birds of California. Pacific Coast Avifauna, No. 27. 12 Bubo virginianus (con't.) Hoechlin, D. R. 1976. Development of Golden Eaglets in south- ern California. Western Birds 7:137-152. Hoffraeister, D. F. and H. W. Setzer. 1947. The postnatal development of two broods of Great Horned Owls (Bubo virginianus) . Univ. Kansas Publ., Mus. Nat. Hist"I 1: 157- 1737 Kennard, J. H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. Killpack, M. L. 1951. Short- eared Owl eaten by Horned Owl. Condor 53:262. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. Vol. 50, No. 6. Miller, L. 1930. The territorial concept in the Horned Owl. Condor 32:290-291 Miller, L. 1952. Auditory recognition of predators. Condor 54:89-92. Peters, J. L. 1950. Checklist of birds of the world Vol. IV. Mus. Comp. Zool., Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. Rhoades, D. D. and G. E. Duke. 1977. Cine radio graphic studies of gastric motility in the Great Horned Owl (Bubo virginianus) . Condor 79:328-334. Ridgway, R. 1914. The birds of North and Middle America. Part 6. Bull. U.S. Nat. Mus. No. 50. Small, A. 1974. The birds of California. Macmillan Co., New York. Wiley, J. W. 1975. Relationships of nesting hawks with Great Horned Owls. Auk 92:157-159. f GREEN- TAILED TOWHEE Pipilo chlorurus I TAXONOMY A. Type description AOU (1957), Fringilla chlorura Audubon, Orn. Biogr. , vol. 5, 1839, p. 336. (No locality given = about 20 miles south- west of Blackfoot, Idaho.) B. Current systematic treatments Sibley (1955), discussion of the characteristics illustrating the close relationship with both P. ocai and P. erythrophthalmus (color pattern, ecological preferences, pattern of song, coloration and pattern of markings of the eggs), concluding that C. chlorura and P. ocai are congeneic and that chlorura should" be placed in tHe genus Pipilo. Paynter (1970), recognizes chlorurus as a monotypic species in the genus Pipilo, which is divided into seven species. Passeriformesl Emberizidae (Emberizinae) . C. Synonomies of scientific nomenclature ► Dawson (1923), Oberholseria chlorura. AOU (1957), Chlorura chlorura; Fringilla chlorura. Ridgway (1901), Oreospiza chlorura. Grinnell and Miller (1944), Embernagra blandingiana; E. chlorura; Atlapes chlorurus; Oberholseria chlorura zapolia. D. Synonomies of verncular nomenclature Dawson (1923), Green-tailed Finch; Blanding's Finch. Grinnell and Miller (1944), Blanding Finch; Green Finch; Green-tailed Bunting. II DESCRIPTION A. External morphology of adults Dawson (1923), "Sparrow size; chestnut crown, white throat; greenish coloration of upper parts, especially tail and wings. . .Adults (sexes alike): Crown and occiput rich chest- nut; forehead blackish gray, with whitish loral spot on each side; cheeks mingled gray and white; a short malar streak white, and a narrow, sharply defined sub-malar streak dark gray; remaining upperparts olive-gray, tinged more or less with bright olive-green. Wings and tail with brighter greenish edgings. .. ;bend of wing, axillars, and under coverts yellow; chin and throat white, sharply defined and with con- j^ vex posterior outline; sides of head and neck and remaining P underparts neutral gray, clearing to white on abdomen, tinged Pipilo chlorurus (con't.) with buffy or brownish on sides, flanks, and crissum; under tail-coverts clear cream-buff. Bill blackish above, paler below; legs brown, toes darker; irides cinnamon." Peterson (1961), "rufous cap and conspicuous white throat ...plain olive-green back, gray breast." Ridgway (1901), detailed description of adult male and female, including plumage, soft parts, and measurements. B. External morphology of subadult age classes Dawson (1923) "Immature birds are brown above, tinged with greenish and streaked with dusky, but with wings and tail much as in adult. Nestlings show greenish on wings alone, and are otherwise finely streaked above and below." Ridgway (1901), detailed description of plumage. C. Distinguishing characteristics Interspecific - Dawson (1923), "chlorura possesses no color character not found in at least one other member of the genus Pipilo; and the very fact that this bird has these characters in common with the others would seem to designate it as a typical and central member of the genus, rather than an aberrant form" Peterson (1961), "Brown Towhee is browner, has buff throat." ^ Intraspecific - I GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species Dawson (1923), "Western United States and northern Mexico; breeding from central Oregon and south central Montana to western Texas and southern California." AOU (1957), "Breeds from southwestern and central Oregon. . . southeastern Washing- ton (Blue Mountains), southern Idaho, southwestern Montana... and northwestern, central, and southeastern Wyoming (Yellow- stone Park, Wheatland) south through the interior mountains to southern California (San Jacinto Mountains), southern Nevada (Charleston Mountains), central Arizona (San Fran- cisco Mountains, White Mountains), and southern New Mexico (Black Mountains, Sacramento Mountains) .. .Casual north to Saskatchewan. .. and east to Massachusetts. . .New Jersey... Virginia. .. South Carolina. . .and Louisinna." Ridgway (1901) "Mountain districts of Western United States, from more eastern Rocky Mountain ranges to Coast Range of California; north to central Montana and Idaho and eastern Washington; south at least in winter, Lo States of Guanajuato, Durango . . . , and Sinaloa. . .middle Mexico, and to southern extremity of Lower California." Pipilo chlorurus (con't.) B. California distribution of the species Dawson (1923), "Summer resident in high Transition, chiefly east of the Sierran divide, from the Warner Mountains south to the desert ranges and the San Jacinto Mountains. Also breeds, northwesterly, at least to Sissons..., and south- westerly to Mt. Pinos..., and south centrally along the western slopes of the Sierras. Abundant during migrations easterly; and recorded variously in the northern Coast Range south to Mendocino County, Sierra Nevada south through Mt. Pinos and Transverse Ranges to Mt. San Jacinto in Penin- sular Ranges; Great Basin south through mountains of Inyo County." Grinnell and Miller (1944), "As breeding, northern coast ranges, west to interior Humboldt County and south to northern Mendocino County; Cascade Mountains, Sierra Nevada, and high ranges of southern California west to Mount Pinos and southeast to Mount San Jacinto; mountains and high plateaus of Great Basin region from Modoc County south through Inyo County." C. California desert distribution Grinnell and Miller (1944), recorded at the following localities: Palm Springs, Riverside County, Mount Water- man, Los Angeles and Pasadena, Los Angeles County; Watch Creek, San Diego County. D. Seasonal variations in distribution Dawson (1923) "Has occurred in winter in the San Diegan district. . .wintering from southern portion of its breeding range south to Cape San Lucas and Guanajuato." AOU (1957), "Winters from southern California (Los Angeles, Casually), southern Arizona (Fort Mohave, Gila River Valley), and western and southern Texas (Sierra Blanca, Brownsville) south to southern Baja California (San Jose del Cabo), Jalisco, Guanajuato..., Morelos (Cuernavaca) , Nuevo Leon (Galeana) , and Hidalgo (Metztitlan) ; occasionally north to central California (Marysville) ; in migration to western Kansas and western Oklahoma (Cimarron County)." Small (1974), "winter visitor in small numbers in southern Calif- ornia." Grinnell and Miller (1944), "In winter, chiefly Pacific slope north to Los Angeles County, exceptionally as far as Sacramento Valley." Willett (1912), 'Summer resident of the mountains from 5000 to 9000 feet altitude. Occurs occasionally along the base of the mountains during migrations. Winters in small numbers at least as far north as San Bernardino." Pipilo chlorurus (con't.) IV HABITAT A. Biotopic affinities Peterson (1961), "dry brushy mountain slopes, low chaparral, open pines, sage, manzanita." Small (1974), "for breeding, mountain chaparral, otherwise, lowland thickets and oases." Grinnell and Miller (1944), "Chaparral types occurring in the Transition and Boreal zones. Most commonly this essen- tial cover is composed of snow bush (Ceanothus cordulatus) and manzanita, or, eastwardly, of Artemisia tridentata and Purshia. Forest is avoided; only scattered trees within the brushland are tolerated, but they may be used as song posts. The brush cover is typically low (2 to 4 feet) and spreading, affording runways between plants and underneath the foliage. Within forested areas, the places occupied are comparatively dry and well insulated; in the Great Basin region the lower, warmer flats are avoided even though grown to sage brush." Miller (1951), Transition and Canadian life zones. B. Altitudinal range Grinnell and Miller (1944), "breeding localities range from 2500 feet, as at Nevada City, Nevada County, .. .up to 10,000 feet in the white Mountains, Mono County." C. Home range size Austin (1968) reports that no information is available. D. Territory requirements Perch sites - Grinnell and Miller (1944), "scattered trees within the brushland. . .may be used as song posts." Courtship and mating sites - Nest sites - Dawson (1923). "Low in bushes, especially sage (Artemsia tridentata) , often well concealed, .. .of twigs, weed-stems, pine needles, etc. ; lined with rootlets, grasses, or, rarely, horse hair." E. Special habitat requirements F. Seasonal changes in habitat requirements ? Pipilo chlorurus (con't.) f V FOOD A. Food preferences Grinnell, Dixon, and Linsdale (1930), "when berries of amelanchier bushes. . .were turning reddish but were not yet at all ripe, the green- tailed towhees were seeking these eagerly and eating them" Austin (1928) reports them feed- ing on weed seeds, insects, alfalfa weevil, third-instar Mormon crickets, cracked corn, bread crumbs, birdseed, rolled oats. B. Foraging areas Grinnell and Miller (1944) "The sphere of activity is low, foraging taking place on the ground in the leaf litter and in the tangle of branches." C. Foraging strategies Austin (1969) "scratching not unlike that of other kinds of towhees." Grinnell and Storer (1924), "the combination of conical bill, long tail, short wings, and stout legs and feet, proclaim the Green- tailed Towhee to be adapted for foraging beneath brush patches." ^ D. Feeding phenology E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior C. Courtship and mating behavior D. Nesting phenology Dawson (1923), "Season: May- July; two broods." E. Length of incubation period F. Length of nestling period G. Growth rates Austin (1968), "Almost no information is available on parental' care or development of nestlings." Pipilo chlorurus (con't.) H. Post-breeding behavior Austin (1968), "Prior to fall migration proper, there is an up-mountain scattering of birds after the breeding season, and immatures are prevalent among these wanderers. . .There is also evidence of downshape scattering of individuals in late summer." VII POPULATION PARAMETERS A. Clutch size Dawson (1923), "3 or 4; palest bluish or grayish white, finely and almost uniformly sprinkled or spotted with light reddish brown... and purplish gray." B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abundance Huey (1942), "perhaps the most generally distributed winter ^^ visitor. While never in concentrated numbers, it was found singly in almost every place where vegetation was dense enough to give it shelter" (Oregon Pipe Cactus National Monument, Arizona). F. Habitat density figures VIII INTERSPECIFIC INTERACTIONS A. Predation Austin (1968), "while no evidence of predation has come to my attention, probably adults as well as eggs and young of this low-nesting bird occasionally fall prey to mammalian predators. " B. Competition C. Parasitism Henshaw (1875), recorded a cowbird egg in a nest of this species in Fort Garland, Colorado. Rockwell (1908), re- corded this species as a host of Molothrus ater obscurus in Mesa County, Colorado. Mitchell (1898), reports this species as parasitized in San Miguel County, New Mexico. t Pipilo chlorurus (con't.) !X STATUS A. Past population trends Grinnell and Miller (1944), "Present in three seasonal roles common summer resident from May to early September in moun- tains, especially those of the interior; winter visitant rarely, in coastal southern section; transient there and elsewhere, except along northwest coastal strip; migrants are most numerous in the interior." B. Present population status Small (1974), "Transient and summer visitor, April to October." C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status Pipilo chlorurus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Austin, 0. L. , Jr. 1968. Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows, and allies Part 1. U.S. Natl. Mus. Bull. No. 237. Dawson, W. L. 1923. The birds of California. South Moulton Co., San Francisco. Grinnell, J., J. Dixon and J. M. Linsdale. 1930. Vertebrate natural history of a section of northern California through the Lassen Peak region. Univ. California Publ. Zool. Vol. 35. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. Grinnell, J. and T. I. Storer. 1924. Animal life in the Yose- mite. Contr. Mus. Vert. Zool. Univ. California. Henshaw, H. W. 1875. Report upon the ornithological collec- tions. U. S. Geographical Surveys West of the 100th Meri- dian. Vol. V., Chap. III. Huey, L. M. 1942. A vertebrate faunal survey of the Oregon Pipe Cactus National Monument, Arizona. Trans. San Diego Soc. Nat. Hist., vol. 9, pp. 353-376. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool., Vol. 50, No. 6. Mitchell, W. I. 1898. The summer birds of San Miguel County, New Mexico. Auk 15:309. Peters, J. L. 1970. Checklist of birds of the world. Vol. 10. (R. A. Paynter, Jr., ed.) Mus. Comp. Zool., Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. Ridgway, R. 1901. The birds of North and Middle America. Part 1. U.S. Natl. Mus. Bull. No. 50. Rockwell, R. B. 1908. An annotated list of the birds of Mesa Co., Colorado. Condor 10:169. e ~ t Pipilo chlorurus (con't.) Sibley, C. G. 1955. The generic allocation of the Green- tailed Towhee. Auk 72:420-423. Small, A. 1974. The birds of California. Macmillan Co., New York. Willett, G. 1912. Birds of the Pacific slope of southern California. Pacific Coast Avifauna No. 7. ~ • HAIRY WOODPECKER Picoides villosus leucothorectic I TAXONOMY A. Type description Dryobates villosus leucothorectis - AOU (1957) Oberholser, Proc. U.S. Nat. Mus . , 40 , June 3 , 1911, P.. 597 (in key), 608. (Burley, New Mexico) B. Current systematic treatments AOU (1957) calls this species Dendrocopos villosus leucothorectic (Oberholser) and a subspecies of the Hairy Woodpecker. Oberholser (1911) called it Dryobates villosus leucothorectic. Morony, et al. (1975) synonymized this species to Picoides after Dendrocopos, the genus recognized by Peters (1948;. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), "Dryobates villosus hyloscopus, part.", in describing Dryobates villosus leucothorectis . Grinnell (1902), describing Dryobates villosus hyloscopus, "Dryobates villosus harrisi, part, Picus harrisi, Picus # villosus, Picus villosus harrisi, Dendrocopus harrisi." Peters (1948), "Dendrocopos villosus leucothorectic." D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), "Cabanis Woodpecker, part.; White-breasted Woodpecker; Hairy Woodpecker, part.", in describing the White-breasted Hairy Woodpecker. Dawson (1923), "Southwestern Hairy Woodpecker. Arizona Hairy Woodpecker." II DESCRIPTION A. External morphology of adults Dawson (1923), "Males average: wing 126.8 (4.99); tail 79.4 (3.126); bill 30.8 (1.21); tarsus 21.5 (.846). Females smaller." In describing D. v. orius, a similar race differ- ing only by being slightly larger than D. y. leucothorectis, which also has pure white underparts, "Adult male: Above , in general, black, glossy (at least) on head and nape, paling, brownish dusky, on quills; nuchal feathers slightly lengthen- ed, the anterior ones scarlet-red, forming a short nuchal band; nasal tufts dingy white; a narrow white superciliary and a broad white rictal stripe, curving upward and some- times nearly meeting fellow on hind nape (rarely connecting with white of back) ; a black area included on side of head » Picoides villosus leucothorectic (con't.) continuous with nape; a black malar stripe broadening behind; a lengthened white patch down middle of back, connecting with sides of rump, or not; one to several rounded spots of white on middle wing-coverts, or not; primaries (except usually the first) and the outer secondaries marked with angular white spots on outer webs and with large rounded spots on the inner webs, the spots tending to fall into bars on the closed wing; the two outer pairs of tail-feathers white on exposed portion, and the succeeding pair chiefly white on outer web and tip. Bill and feet plumbeous; iris reddish brown. Adult female: Like male, but without red on head." Peterson (1969), "Note the white back, large bill... clear white back. .. spotted with white on wings; males with a small red patch on back of head; females, without." Udvardy (1977), "White head with black crown, eyemask, and 'whiskers. ' Male has red patch at base of crown; light underparts; white back; black wings with white spots. Tail black with white outer tail feathers. Female similar, but lacks red patch." B. External morphology of subadult age classes Dawson (1923) in describing D. v. orius, a similar race, "Like adult, but crown, instead of nape, red (scarlet, grenadine red, grenadine, or even yellowish) ; the forehead and often the crown finely spotted with white." C. Distinguishing characteristics Interspecific - Peterson (1969), "Other woodpeckers have white rumps or white bars on the back, but the Downy and the Hairy are the only common woodpeckers with clear white backs... The Hairy is like a magnified Downy: bill is especially large in relation to Downy' s little bill. Downy at close range shows spots on outer tail feathers. Northern Three- toed Woodpecker of boreal forests may have white back." Robbins, Bruun, Zim (1966), "Easily confused with. . .Northern Three- toed Woodpecker, which has barred sides and a much narrower white eye stripe." Intraspecific - In Bent (1939), "...much like D. v. monticola but decidedly smaller; wing coverts practically always with- out white spots." Dawson (1923), "Adults: Similar to D^ y. orius, but slightly smaller; the underparts pure white. A very dubious race. Bendire (1895), "...it is distinguish- able from the former (D. villosus) by its plain back or much less spotted wing coverts and tertials, and from D. v. harrisii by its lighter-colored underparts and somewKat smaller size. " • * # # Picoides villosus leucothorectis (con't.) I GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) in describing P. villosus, "Central Alaska, middle Yukon, central Mackenzie, northern Manitoba, James Bay, south- central Quebec, and Newfoundland south to north- ern Baja California, Mexico, central Texas, the Gulf coast, southern Florida, the Bahama Islands, and through the moun- tains of Central America to western Panama." In describing P. y. leucothorectis, "Resident in the White Panamint, Coso, Grapevine, and Clark mountains in south- eastern California, the higher mountains in southern Nevada and southern Utah, Arizona (except southwestern deserts, and mountains in southeastern part) western and central New Mexico, and the Guadalupe Mountains in western Texas." B. California distribution of the species Grinnell and Miller (1944), "Life-zones, Upper Sonoran to Hudsonian." Small (1974), "Length of state except Central Valley and deserts of the eastern and southeastern portions." Miller (1951) found them in Inyo Mountains. Grinnell (1915), gives various California locations and found this to be the representative race in the White and Panamint mountains, in Mono and Inyo Counties, and gives additional locations (1918). Mailliard (1918) found them in Yosemite Valley. Willett (1953) also gives various locations. Dawsbn (1923), "...at least the White and Panamint Mountains, ... the bird is decidedly more abundant in the northern and more elevated portions of its range." C. California desert distribution Small (1974) says that this species is not found in eastern and southeastern deserts. Grinnell (1902) says it is found "chiefly in Transition south and east of the northern humid coast belt." Miller (1940) found them at Clark Mountains. Wauer (1962) found them in Death Valley during winter. D. Seasonal variations in distribution Small (1974), if the winters are not too severe, "Resident species such as... Hairy Woodpeckers can remain in the mon- tane forests in considerable numbers." Grinnell (1915) reported as "more widespread throughout winter through the interior valleys west of the Sierras." Willett (1933) reported as "quite numerous in oak regions during severe winters..." In Bent (1953), "Breeds commonly throughout the pine belt, often ascending higher in summer. . .About Picoides villosus leucothorectic (con't.) the middle of June, the young leave their nests, and soon make a partial migration downward towards the lower border of the pine belt.1 Peterson (1969), "...mainly in moun- tains in southwest United States. .. Some down-mountain drift in winter." Dawson (1923), "In summer the bird ranges up to timberline, a little above the normal breeding level; and in winter it visits the live oaks and the sycamores or even takes a turn through the chaparral." Bendire (1895), "It is practically a resident wherever found, and its breed- ing range is coextensive with its geographical distribution. In winter it is often met with in the valleys adjacent to mountain ranges, to which it retires in summer to breed; but these vertical migrations, if they may be called so, are never very extended." IV HABITAT A. Biotopic affinities. Grinnell and Miller (1944), "Broken or scattering forest. Has been found associated with pinon, juniper, white fir, foxtail, limber and hickory pines, mountain mahogany, cotton- wood and aspen." Also gives life-zones as Upper Sonoran to Hudsonian. Small (1974), "Montane forest to Transition Life Zone; also broken and mixed coniferous and deciduous forest. Two Hairy Woodpeckers are also found in relatively pure stands of Black Oak (Oak Woodland) in dry valley floors and on small mesas. Miller (1951) found these in Upper Sonoran, Transition, Canadian, and Hudsonian Zones, pinon- juniper formations, riparian woodlands, coastal forest, montane forest, and subalpine forest. Peterson (1969), "Montane forests, woodlands, river groves." Robbins, Bruun, Zim (1966), "Fairly common, especially in mature deciduous or mixed woods." Udvardy (1977), "Deciduous trees; coniferous stands, especially in montane forests and river groves." Dawson (1923), "...favorate resorts are old burns and the edges of clearings, logged-off areas, open, rangy woods, and interrupted groves. B. Altidudinal range Grinnell and Miller (1944) reported 6200 to 9000 feet as altitudes of capture of specimens. Bendire (1895), reported it up to 10,000 feet. C. Home range size D. Territory requirements » Perch sites - • Picoides villosus leucotherectic (con't.) Courtship and mating sites - Bendire (1895) reported that males drum on resonant dry limbs to attract females. Nest sites - Peterson (1969), "In holes in tree stub." Udvardy (1977), "...eggs on wood chips in a previously used tree hole or newly excavated cavity. Dawson (1923), says nests are excavated in trees such as dead firs or pines and sometimes living alders. The nest height is from 4 to 80 feet from the ground and about 10 inches deep. E. Special habitat requirements Ligon (1970) reports that they need standing dead timber to breed. F. Seasonal changes in habitat requirements V FOOD A. Food preferences In Bent (1939), reports of "small black beetles. . .wood ants. . .woodbo ring larvae, caterpillars, moth pupae, other insects and mast." Dawson (1923) reports worms and larvae from trees. Nearly half of the food is larvae of wood- boring beetles (Cerambycidae and Buprestidae) , the rest being caterpillars, wild raspberries and blackberries, cornel berries, acorns, pits of the evergreen cherry. Bendire (1895), "...food, which consists principally of injutious larvae and eggs of insects, varied occassionally with a diet of small berries and seeds, ... .pinon nuts, pine seeds, and acorns." Also, around slaughterhouses, small bits of meat and fat. B. Foraging areas Bendire (1895) and Dawson (1923) both give examples of the trees upon which these birds feed and which include apple trees, oaks, willows, etc. C. Foraging strategies Udvardy (1977), "Woodpeckers secure their food by hammer- ing holes through bark and then extracting grubs with their extremely long, flexible tongues." Bendire (1895) describes the feeding behavior of these birds (chiseling at trees with bill while hanging on with sharp claws and using tail as support), and the use of the tongue. Kisiel (1972) discusses how Hairy and Downy Woodpeckers divide the resources by feeding on different species of trees. Neff (1928), reports that they tunnel for insects and probe with their tongues for the larvae. Picoides villosus leucothorectic (con't.) D. Feeding phenology ^^ Dawson (1923) reports wild blackberries and raspberries are eaten in summer and acorns, cornel berries, and pits of the evergreen cherry are eaten in winter. Bendire (1895) reports the birds eating pinon nuts, pine seeds, and acorns in winter and insect eggs and larvae and berries at other times. Also, some fat and meat from slaughtered animals in winter. E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Dawson (1923) reports strong defense of the nest, especially by the male. Bendire (1895; reports that they drive other species of woodpeckers from their feeding grounds. Kilham (1960) reports that males and females have separate fall and winter territories, and "mark" them by drumming. C. Courtship and mating behavior Bendire (1895) described the male drumming which he believed was to attract a female. He thought they remained paired for life. The female incubates the eggs as well as the male, and both build the nest. Carpenter (1919) believes they remain mated for a number of years as well as Willard (1918). Kilham (1960) reports that the female may attract the male by drumming in her fall and winter territory and join him in display flights. D. Nesting phenology Willett (1933) reported as breeding mostly in April and May. Dawson (1923) reported incubation to begin from the last week in March to the last of May. Bendire (1895) reported that mating season begins in March (latter part). Eggs are laid in April -May. E. Length of incubation period Bendirc (1895), "2 weeks." F. Length of nestling period Bendire (1895) "about 3 weeks." G. Growth rates Picoides villosus leucothorectic (con't.) H. Post-breeding behavior Dawson (1923) reported only one brood is raised per season. Bendire (1895), reported that they care for the young for some time after they have left the nest. VII POPULATION PARAMETERS A. Clutch size Willett (1933) reported clutches of 3 and 4 eggs. Bent (1939) reported clutches of the same amount. Peterson (1969), "Eggs (3-6)." Udvardy (1977), "3-6 eggs." Dawson (1923) reported 4 or 5. Bendire (1895), 3-6, commonly, 4. B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abundance Neff (1928) found them more abundant in a given area in winter. During the other seasons, they tend to associate ^ only in pairs or singly. F. Habitat density figures Koplin (1969) reports that density changes as the amount of prey items change due to fire and floods. For example, there is a 50-fold increase in response to insect increase due to a fire. Neff (1928), "The Hairy Woodpeckers are not especially companionable and seem to prefer the more secluded timber or the wooded mountain sides. . .Generally, they work in pairs... Only during the winter months do they venture in any numbers." Short (1971), "The Hairy Woodpeckers re- quire much larger territories. . .hence their populations are less dense than those of pubescens and nuttallii." VIII INTERSPECIFIC INTERACTIONS A. Predation B. Competition Bendire (1895), "It does not live in harmony with smaller species of its own kind, and drives them away, when they • encroach on its feeding grounds." Ligon (1970) reports competition for nesting and foraging sites with the Red- cockaded Woodpecker. Picoides villosus leucothorectic (con't.) C. Parasitism IX STATUS A. Past population trends Grinnell (1902), reported it as "a common resident in suit- able localities throughout the State." Grinnell (1915) reported it as a common resident in the Canadian, Transition, and high Upper Sonoran zones except in northwest humid coast belt. Willett (1933) reported it as a common resident of mountains and less common in lower country. B. Present population status Grinnell and Miller (1944) reported it as permanently resi- dent. Numbers usually small and individuals wisely scatter- ed. Small (1974) reported it as a resident. Ligon (1970) believes the numbers are now greater in open pine land than previously. C. Population limiting factors Ligon (1970) reports that reduced standing dead timber decreases the population. D. Environmental quality: adverse impacts Ligon (1970) reports that they need dead standing timber to breed, and repeated fires reduce this. E. Potential for endangered status ♦ Picoides villosus (con't.) FXI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American Birds. 5th Edition. American Ornithologists' Union. The Lord Baltimore Press, Inc. Baltimore, Mary- land. 691. pp. Bendire, C. 1895. Life histories of North American birds. Volume 2. Smithsonian Contributions to Knowledge #985. Smithsonian Institution, Washington, D.C. 518 pp. Bent, A. C. 1939. Life histories of North American wood- peckers. Smithsonian Institution. United States National Museum Bulletin #174. U.S. Gov't. Printing office. Washington. 334 pp. Carpenter, N. K. 1919. Evidence that many birds remain mated for a number of years. Condor 21:28-30. Dawson, W. L. 1923. The birds of California. Volume Two. South Moulton Company. San Diego. 1432 pp. Grinnell, J. 1902. Checklist of California birds. Pacific Coast Avifauna #3. Cooper Ornithological Club. Santa Clara, California. 98 pp. Grinnell, J. 1915. A distributional list of the birds of California. Pacific Coast Avifauna #11. Cooper Ornith- ological Club. Hollywood, California. 217 pp. Grinnell, J. 1918. Seven new or noteworthy birds from east- central California. Condor 20:86-90. Grinnell, J. and A. H. Miller, 1944. The distribution of the birds of California. Pacific Coast Avifauna Number 27. Cooper Ornithological Club. Berkeley, California. 608 pp. Kilham, L. 1960. Courtship and territorial behavior of hairy Woodpeckers. Auk 77:259-270. Kilham, L. 1972. Reproductive behavior of White-breasted Nuthatches. Auk 89:115-129. Kisiel, D. S. 1972. Foraging behavior of Dendrocopos villosus and D. pubescens in eastern New York State. Condor 74: 393-399. Koplin, J. R. 1969. The numerical response of woodpeckers to insect prey in a subalpine forest in Colorado. Condor 71: 436-438. 10 Picoides villosus (con't.) Ligon, J. D. 1970. Behavior and breeding biology of the Red- cockaded Woodpecker. Auk 87:255 278. Mailliord, J. 1918. Early autumn birds in Yosemite Valley. Condor 20:11-19. Miller, A. H. 1940. A transition island in the Mohave Desert. Condor. 43:161-163. Miller, A. 1951. An analysis of the distribution of the birds of California. University of California Publications in Zoology. Vol. 50, #6, pp. 531-644. Morony, J. J. Jr., W. J. Bock, J. Farrand, Jr. 1975. Reference list of the birds of the world. The American Museum of Natural History. New York. 207 pp. Neff, J. A. 1928. A study of the economic status of the com- mon woodpeckers in relation to Oregon Horticulture. Free Press Print, Marionville, Mo. 68 pp. Oberholser, H. C. 1911. A revision of the forms of the Hairy Woodpecker (Dryobates villosus CLinnaeusj) . Proc. U.S. Nat . Mus . , vol. 40, pp. 595-621 . Peters, J. L. 1948. Checklist of birds of the world. Vol. VI. Harvard University Press. Cambridge. 259 pp. Peterson, R. T. 1969. A field guide to western birds. Houghton Mifflin Company. Boston. 366 pp. Ridgway, R. 1914. The birds of North and Middle America. Part VI. Bull, of the U.S. Nat'l. Museum. Gov't. Print- ing Office. Washington, D. C. 822 pp. Robbins, C. S. , B. Bruun, H. S. Zim. 1966. Birds of North America. Western Publishing Company, Inc. Racins, Wiscon- sin. 340 pp. Short, L. L. 1971. Systematics and behavior of some North American Woodpeckers, Genus Picoides (Aves). Bull, of the Am. Mus. of Nat'l. Hist, vol"! 145: Article 1, pp. 1-118. Small, A. 1974. The birds of California. Winchester Press. New York. 310 pp. Udvardy, M. D. F. 1977. The Audubon Society Field guide to North American birds. Alfred A. Kropf, Inc. New York. 855 pp. 11 Picoides villosus (con't.) Wauer, R. H. 1962. A survey of the birds of Death Valley. Condor. 64:220-233. Willard, F. C. Evidence that many birds remain mated for life. Condor 20:167-170. Willett, G. 1933. A revised list of the birds of Southwestern California. Pacific Coast Avifauna #21. Cooper Ornithol- ogical Club. Los Angeles, California. 204 pp. * ♦ ♦ t HOUSE FINCH Carpodacus mexicanus I TAXONOMY A. Type description AOU (1957), Fringilla frontalis, in Long, Exp. Rocky Moun- tains, vol. 2~, 1823, p. 40 (note). (Arkansas River near the mountains = near Colorado Springs, Colorado.) B. Current systematic treatments Howell, Paynter, and Rand (1968), recognize twenty-one species of the genus Carpodacus ; twelve subspecies of the species mexicanus . Order: Pass eri formes; Family: Fringillidae (Carduelinae) . C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Fringilla frontalis; Erythrospiza frontalis; Carpodacus frontalis; Carpodacus familiaris; C. rhodocolpus; C. jE. rhodocolpus; C. IT. frontalis; C. dementis; C. mexicanus obscurus; C. m. dementis; C. m. solitudinus ; C. m. grinnellii. V D. Synonomies of vernacular nomenclature Dawson (1923), Crimson-fronted Finch; Burion; California Linnet. Grinnell and Miller (1944), Crimson-necked Finch; Crimson- fronted Purple Finch; Purple House Finch; California Purple Finch; Domestic Purple Finch; Red Linnet; House Linnet; Linnet; Red-fronted Linet; California House Finch; Crimson House Finch; San Clemente House Finch; Grinnell House Finch; Desert House Finch. II DESCRIPTION A. External morphology of adults Dawson (1923), "Adult male in highest spring plumage: Head and neck all around, throat, and breast, broadly, and rump, rich red (carmine, light carmine, or napal red), or, rarely, tinged with orange; upper back more or less tinged with the same shade...; remaining upperparts, wings, and tail brownish gray, or fuscous; margins of feathers vaguely paler; remain- ing underparts whitish finely streaked with brownish gray. . . Bill horn-color; feet and legs dark brown. In autumn, the reds duller (grayer), more blended, and more widely diffused; the intensity of red, especially, reduced on crown, where varied by darker centers to feathers (pure only on forehead) ; Carpodacus mexicanus (con't.) the wings with many edgings of pinkish, or brownish buffy, not present in spring. In this plumage the appearance of C. m. frontalis very closely approximates that of C. purpureus . . .Adult female in spring: Above dull grayish brown, streaked with darker; below dull white, sharply and finely streaked with grayish brown or dusky; wings and tail grayish brown without distinguishing marks. Adult female in fresh fall plumage: Above, plumage more blended; wings with some mar- ginings of lighter (buffy gray); below, streaks broader and less distinct by reason of buffy edgings." Ridgway (1901), detailed description of C. m. mexicanus with comparison with frontalis, including plumage, soft parts, and measure- ments. Michener and Michener (1931), discussion of color variation in the plumage of males--based upon observations during banding activities. Peterson (1961;, "Male: Near size of House Sparrow, brownish with bright red breast, forehead, stripe over eye, and rump. . .Female: Sparrow-like; gray-brown above; underparts streaked with dusky; face with- out strong stripings, bill stubby." B. External morphology of subadult age classes Dawson (1923), "resemble the female parent, but are more finely streaked with dusky below, and more heavily margined by brownish buffy, especially on wing-coverts and tertials." C. Distinguishing characteristics Interspecific - Dawson (1923), "red never so widely diffused above as in C. purpureus californicus) . . .Female not certainly distinguishable from that ot Purple Finch in autumn, but upper plumage rather more blended and grayer, less olivaceous." Peterson (1961), male: "Resemble males of Purple and Cassin's Finches (which do not nest about buildings); is brighter red. Some are almost orange. Narrow dark stripes on flanks and belly are best distinction." Intraspecific - Ridgway (1901), "Smaller than C. m. mexicanus and C. m. rhodocolpus, but larger than C. m. sonoriensis and C. m. ruberrimus ; in coloration, the adult male intermediate "Between the first named and the rest in extent of the red, this being less restricted and less sharply defined and less intense than in C. m. mexicanus, the crown, occiput, and back often tingecl with red, but rarely to the same extent as in C. m. rhodocolpus; C. m. sonoriensis, and C. m. ruber- rimus; female rather grayer and more distinctly streaked above than that of C. m. mexicanus." ♦ t Carpodacus mexicanus (con't.) I GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species Dawson (1923), "Western United States from Oregon, southern Idaho, and southern Wyoming, east upon the plains to Kansas, and south throughout Lower California and to southern border of the tableland of Mexico." C. m. frontalis: As above, excepting the southern half of Lower California and the southern portion of old Mexico." AOU (1957), "Breeds, and largely resident, from southwestern and south-central British Columbia (Victoria, Williams Lake, Okanagan Landing), central western and southern Idaho (Moscow, Boise, Pocatello), central northern and southeastern Wyoming (Big Horn Valley, Tarring - ton), and western Nebraska (Kimball County, Haigler) south through California, including the northern Channel Islands, to central Baja California (Todos Santos Islands, Cedros Island, Santana) , central Sonora (Tiburon Island, San Pedro Martir Island, Oposura) , northwestern Chihuahua (Chihuahua), and western and south-central Texas (Boquilla, Somerset, Austin). Introduced in Hawaii, and on Long Island, New York, where now (1956) breeding in southern Nassaw and southwestern Suffolk counties; breeding also in Greenwich Township, Fairfield County, southwestern Connecticut." B. California distribution of the species Dawson (1923), "Abundant resident throughout the State below Transition." Grinnell and Miller (1944), "Breeds in all sections of State, exclusive of high montane areas and coastal islands from Santa Barbara Island southward, where replaced by the race dementis; of but scattered occurrence within northwest coastal belt. Life-zones, Lower Sonoran and Upper Sonoran; locally in Transition." Keeler (1890), "In California it resorts chiefly to the valleys, both of the coast and interior region, but it occurs in the mountains to the height of at least three thousand feet." C. California desert distribution Smyth and Coulombe (1971) report this species frequenting desert springs for drinking, Upper Carrizo Spring, Riverside County. D. Seasonal variation in distribution AOU (1957), "In winter to the Gulf coast of southern Texas. Casual north to Alberta (Topaz Lake) and Montana (Santon Lake), east to northeastern Texas (Fort Worth), and south to southern Sonora (Chinobampo) ." Grinnell and Miller (1944), Carpodacus mexicanus (con't.) "Wanders to some degree, especially in late summer, but definite migratory movements not apparent. Evidently de- parts in winter from some higher points in breeding range, especially along eastern flank of Sierra Nevada." Salt (1952), "Throughout much of their range house finches move up into the mountain valleys in the late summer after the breeding season and return to the lowlands with the onset of colder weather." Keeler (1890), "Its distribution in winter does not differ essentially from its summer range, as its migrations are caused merely by local influences, such as scarcity of food or a cold spell." IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), "Open places and sunshine are favored and in the foothill districts, great interior valleys and coastal plains the House Finch is the predominant avian species in fields and orchards, and about scattered trees and ranch buildings." Small (1974), "open woodland, edges of forest, woodland, and chaparral; desert cities, towns, suburbs, gardens, parks, farms, ranches, agricultural land, savannah." Miller (1951), Upper and Lower Sonoran and Transition life zones. B. Altitudinal range Grinnell and Miller (1944), "Altitudes of nesting range from -200 feet as in Death Valley, Inyo County, up rarely to 8000 feet, as at Mammoth, Mono County. . .May occur even higher in late summer." C. Home range size Gullion (1960), "highly mobile species, capable of moving considerable distances from one food supply to another." D. Territory requirements Perch sites - Salt (1952), "Any structure will do: the ridge pole of a house, a telephone pole, or the top of a tree." Courtship and mating sites - Nest sites - Thompson (1960a), "in dense foliage and often build in ivy under the eaves of a building, if such a site is available. In the absence of dense foliage or a man-made structure, they may nest in crannies on cliffs." Robertson (1931a), "The loose bark of the blue gum seems to have been designed especially for Linnets ... to nest in. They build m Carpodacus mexicanus (con't.) i behind slabs of bark on the trunks or larger limbs, or in accumulations of bark in the crotches." Dawson (1923), "nest almost anywhere ... Caught in vines, or placed on timbers, under cornices, in bird-boxes, mail boxes." Bergtold (1913), "in vines about houses, in sheltered corners and awnings of buildings. . .in any place of vantage about a building ...In globes, when partly broken, surrounding incandescent lamps. E. Special habitat requirements Grinnell and Miller (1944), "Habitat--Remarkably varied, the following apparent requirements being met by a great diversity of situations: (l) water, at least within a fairly wide daily cruising radius, fruits perhaps forming a satis- factory substitute; (2) open ground of limited or great extent thus affording growths of low seed-producing plants, especially composites; (3) sources of fruits and berries during part of year (possibly not essential); (4) trees, cliffs and earth banks, or man-made structures for roosting and placement of nests above ground in sites often partly enclosed. These requisites are not met in forest associa- tions or continuous chaparral, although they may be found in woodland formations, in forest and chaparral edges and on treeless plains and deserts; low temperatures in summer i and high rainfall and heavy wet fogs either hold low the number of individuals or seem to account for the absence of the species in some areas." F. Seasonal changes in habitat requirements V FOOD A. Food preferences Thompson (1960a) "primarily seedeaters. . .but they also eat fruit, and are considered a pest by fruit growers. . .Ripe thistle. . .other composites." Fisk and Steen (1976), report this species feeding on nectar (at feeders in California). Bergtold (1913), "will eat almost anything vegetable, though it prefers seeds." B. Foraging areas Thompson (1960a) "Large numbers. . .are attracted to fields of blooming and fru and radi sh( Raphanus C. Foraging strategies of blooming and fruiting wild mustard (Brassica campestris) sativus) in the spring." # Salt (1952), "either forage directly on the ground, or they may pick the seeds and flowering heads from the plants while hanging onto the stems or branches." Carpodacus mexicanus (con't.) D. Feeding phenology- Salt (1952), "rely throughout the year more on ground feed- ing...During the breeding season about three-fourths of their food consists of seeds of annual grasses and forbs...As in some other fringillids, the food preferences of this species changes from one species of plant to another during the course of the growing season, depending upon the time at which the seeds develop." Bergtold (1913), "In winter when the ground is unusually deeply covered by snow, these birds wander far and wide over the prairie and vacant city lots, eating weed seeds." E. Energy requirements Partin (1933), detailed study of daily and seasonal fluctua- tions in body weight; adult males and females and young. VI REPRODUCTION A. Age at first breeding B. Territorial behavior Thompson (1960a), 7!In early spring when pairs are forming, aggressive behavior reaches a peak. Increasingly, males ^^ become intolerant of other males perched near them. Males, when they have secured a mate, defend the area around the female... The peak of aggressive activity continued through the selection of a nest site and the construction of the nest, but it begins to wane by the time the nest is com- pleted. The area around the nest is defended rather sporadi- cally and weakly. Vigorous displays are rarely observed in territorial defense. Usually the defender merely flies to a perch near the intruder and sits until the latter moves away." Thompson (1960b), detailed discussion of agressive behavior. C. Courtship and mating behavior Thomspon (1960a), "The first evidence of pair formation in captive House Finches is billing, accompanied by soft twittering. . .Later the male accompanies this mock feeding with regurgitating movements of the throat, but no food passes into the female's open mouth... The female usually begins to big from the male. . .At about the time of nest building, the male actually feeds the female regurgitated material .. .Copulation in the House Finch normally occurs at the invitation of the female." ^ • Carpodacus mexicanus (con't.) D. Nesting phenology Davis (1933), reports in Butte County, California the first date as 16 April; the last date as 9 May; the average date as 28 April. Dawson (1923), "March to July; 2 or 3 broods." E. Length of incubation period Evenden (1957), "The average incubation period for the 11 nests was 13.27 days. . .Extremes of 12 and 14 days." Berg- told (1913), "The average length of incubation is 14 days." F. Length of nestling period Evenden (1957) "residence of individual young varied from 11 to 19 days within one nest, with nest averages ranging from 13.2 to 17.0 days; the overall average was 15.1 days." Bergtold (1913), "The young remained about fourteen days in the nest." G. Growth rates Evenden (1957), "it was noted that growth rates varied from young to young, nest to nest, month to month, and year to year." Keeler (1890), "The growth of the young bird is # rapid and constant. In ten days the chord of the culmen had grown from four to eight millimeters, the gape had increased from five and a half to eleven millimeters, and the tarsus from five to fourteen millimeters." H. Post-breeding behavior Thompson (1960a), "It is not known what happens to the young just after they leave the nest, but they probably do not join large feeding flocks during the several weeks when they are fed by both parents. Later on juveniles and adults may assemble where food is plentiful..." Austin (1968), "With the close of the nesting season in late summer, house finches of all ages begin to gather in flocks and search out the larger tracts of maturing weeds, whence they flush and circle in clouds." VII POPULATION PARAMETERS A. Clutch size Evenden (1957), "completed clutches averaged 4.4 eggs." Thompson (I960), "The nests examined in Strawberry Canyon averaged 4.7 eggs per clutch, with a range of three to • six." Carpodacus mexicanus (con't.) B. Fledging success Evenden (1957), "There was a 52 per cent fledging success based on 110 eggs laid, and a 70 per cent fledging success based on 80 young hatched." C. Mortality rates per age class Bergtold (1913), "Over forty per cent of the eggs laid were ultimate failures, the largest factor in the loss being destruction of the eggs and young by the English Sparrow ...About ten per cent loss is caused by late spring storms, climatic conditions lasting but a short time." D. Longevity Michener and Michener (1933), report ages of birds based upon banding records. Of known-age individuals when first banded, recaptured individuals, 7 males were 4 years and 8 months old; two were 5 years and 7 months old; one female was 6 years and 8 months old. Of individuals whose ages were not known when first banded (as adults), five were at least 5-1/2 years old; one was at least 6-1/2 years old; two were at least 8-1/2 years old. E. Seasonal abundance Austin (1968), "Even in the mildest regions of coastal California, the numbers of the house finch are distinctly less in winter, though some remain throughout the year in almost all localities." F. Habitat density figures Gaines (1974), reports 35 territorial males per square kilo- meter in clumped cottonwood and willow woodland, Glenn and Butte Counties, California. IIII INTERSPECIFIC INTERACTIONS A. Predation Bond (1936), reported two pellets of the Prairie Falcon containing remains of this species, San Luis Obispo, Calif- ornia. Evenden (1957), "Neighborhood cats accounted for almost the entire loss of young." Sumner (1928), reports a headless immature in the nest of Screech Owls." • Carpodacus mexicanus (con't.) B. Competition Evenden (1957), "Competition between House Finches and House Sparrows for nesting sites was particularly strong early in the season." (Sacramento, California). Thompson (1960a), "It is more often the somewhat larger and heavier House Sparrow which wins fights between the two species." Berg- told (1913), "The loss of nests, eggs and young of the House Finch through direct destruction by the English Sparrow is very large. It was 16% in some of the nests studied... the English Sparrow overcomes, and is superior to, the House Finch in the biologic struggle." C. Parasitism Hanna (1933), reports on incident of the nest of this species containing 3 eggs of the finch and one of the Dwarf Cowbird. The nest was deserted. A nest of a Black Phoebe contained four eggs of the House Finch and one of the phoebe; the phoebe at this time was building a new nest a few feet away. Robertson (1931b), reports finding cowbird eggs in the nests of this species. Evenden (1957), "Brown-headed Cowbirds (Molothrus ater) were present but did not parasitize finch nests in this area." X STATUS A. Past population trends Grinnell and Miller (1944), "Permanent resident. Abundant generally, except in situations marginal from the standpoint of zone and habitat." B. Present population status Small (1974), "common resident." C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status 10 Carpodacus mexicanus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Austin, 0. L. , Jr. 1968. Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows, and allies. Part 1. Bull. U.S. Nat. Mus. No. 237. Bergtold, W. H. 1913. A study of the House Finch. Auk 30: 40-73. Bond, R. M. 1936. Some observations on the food of the Prairie Falcon. Condor 38:169-170. Davis, W. B. 1933. The span of the nesting season of birds in Butte County, California, in relation to their food. Condor 35:151-154. Dawson, W. L. 1923. The birds of California. South Moulton Co. , San Francisco. Evenden, F. G. 1957. Observations on nesting behavior of the House Finch. Condor 59:112-117. Fisk, L. H. and D. A. Steen. 1976. Additional exploiters of nectar. Condor 78:269-271. Gaines, D. 1974. A new look at the nesting riparian avifauna of the Sacramento Valley, California. Western Birds 5(3): 61-80. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna, No. 27. Gullion, G. W. 1960. The migratory status of some western desert birds. Auk 77:94-95. Hanna, W. C. 1933. House Finch parasitized by Dwarf Cowbird and Black Phoebe nests occupied by House Finch. Condor 35:205. Keeler, C. A. 1890. Observations on the life history of the House Finch (Carpodacus mexicanus frontalis) . Zoe 1:172- 176. Michener, H. and J. R. Michener. 1931. Variation in color of male House Finches. Condor 33:12-19. <~ T 11 Carpodacus mexicanus (con't.) Michener, H. and J. R. Michener. 1933. Ages of House Finches trapped during February, 1933, at Pasadena, California. Condor 35:183-185. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. Vol. 50, No. 6. Partin, J. L. 1933. A year's study of House Finch weights. Condor 35:60-63. Peters, J. L. 1968. Checklist of birds of the world. Vol. 10. (T. R. Howell, R. A. Paynter, Jr., and A. L. Rand, eds.). Mus. Comp. Zool., Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co. , Boston. Ridgway, R. 1901. The birds of North and Middle America. Part 1. Bull. U.S. Nat. Mus. No. 50. Robertson, J. McB. 1931a. Birds and eucalyptus trees. Condor 33:137-139. Robertson, J. McB. 1931b. Some changes in the bird life of western Orange County, California. Condor 33:204-205. Salt, G. W. 1952. The relation of metabolism to climate and distribution in three finches of the genus Carpodacus. Ecological Monographs 22:121-152. Small, A. 1974. The birds of California. Macmillan Co., New York. Smyth, M. and H. N. Coulombe. 1971. Notes on the use of desert springs by birds in California. Condor 73:240-243. Sumner, E. L. , Jr. 1928. Notes on the development of young Screech Owls. Condor 30:333-338. Thompson, W. L. 1960a. Agonistic behavior in the House Finch. Part I: Annual cycle and the display patterns. Condor 62:245-271. Thompson, W. L. 1960b. Agonistic behavior in the House Finch. Part II: Factors in aggressiveness and sociality. Condor 62:378-402. I - ♦ • LADDER-BACKED WOODPECKER Picoides scalaris cactophilus TAXONOMY A. Type description Dryobates scalaris cactophilus - AOU (1957) Oberholser, Proc. U. S. Nat. Mus., 41, June 30, 1911, P. 140 (in key), 152. (Tucson, Arizona) B. Current systematic treatments Oberholser (1911) split Dryobates scalaris into 15 sub- species, one of which was D. _s. cactophilus. AOU (1957) calls this same species Dendrocopos scalaris cactophilus (Oberholser), and a subspecies of the Ladder-backed Wood- pecker. Morony, et al. (1975) synonymized this species to Picoides after the genus Dendrocopos recognized by Peters (194SJ; C. Synonomies of scientific nomenclature Grinnell and Miller (1944) in describing Dryobates scalaris cactophilus, "Dyctiopicus lucasanus ; Picus scalaris, part; Dryobates scalaris; Dendrocopus scalaris; Dryobates scalaris bairdi ; Dryobates scalaris lucasanus ; Dendrocopus lucasanus ; Dryobates scalaris yumanensis; Dryobates scalaris mojavensis. " Grinnell (1915), "Dryobates~~Tucasanus. " Peters (1948), "Dendrocopos scalaris cactophilus." *TT" • D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), in describing the Cactus Ladder- backed Woodpecker, "Barred Woodpecker; Arizona Woodpecker; Ladder-backed Woodpecker, part; Texan Woodpecker, Mojave Ladder-backed Woodpecker." Peterson (1969), "Mexican Wood- pecker." II DESCRIPTION A. External morphology of adults Peterson (1969), "The only black and white "zebra-backed" woodpecker with a black and white striped face in the arid country. . .Males have red caps." Robbins, Bruun, Zim (1966), "Note the distinct black and white on side of head." Dawson (1923), "Adult male: Extreme forehead and nasal tufts snuff-brown, shading into sooty brown of forehead, thence through black of crown, narrowly tipped with scarlet- red and broadly subtipped with white, to nearly pure scarlet- red on sides of occiput and nape, the fore-crown thus speckled with white and red in varying proportions; cervix (narrowly), Picoides scalaris cactophilus (con't.) upper tail-coverts, and tail from above, black; back and wings sooty brown or brownish dusky, heavily and equally barred or spotted with white, the spotting of wings involv- ing flight-feathers arranged in rows, equivalent to bars when in repose; sides of head and neck, including super- ciliaries and remaining underparts, pale buffy brown fading to white on sides and crissum; included area of sides of head black, invaded by malar streaks of buffy brown or whitish; the sides of breast sharply and heavily spotted with brownish black; the sides, flanks, and crissum indis- tinctly barred with dusky; the under (outer) feathers of the folded tail equal-barred black-and-white. Bill and feet dusky horn-color; iris brown. Adult female: Like male, but without red on crown or nape, glossy black instead, shading to sooty brown on forehead; forehead sometimes sparingly speckled with white. Length of adult male: 158.75-184.2 (6.25-7.25); wing 104 (4.09); tail 60.8 (2.39); bill 22.7 (.89); tarsus 18.1 (.71). Females' average slightly less." B. External morphology of subadult age classes Bent (1939), assumes young are hatched naked (as in other woodpeckers). Juvenile plumage is acquired before young leaves the nest, and is like that of an adult male, but the sexes are not alike. Male: Forehead, sides of occiput, and nape are uniform black. Crown is scarlet, more or less dotted with white. Female: has much less scarlet on crown. In both, back is barred with dull black and grayish white. Underparts are "vinaceous-buff , " faintly spotted on the sides and flanks. Plumage is softer and markings are not as clearly defined as in adult." Dawson (1923), "Young male: Like adult male, but nape and sides of occiput black, the red carried forward and prevailing on crown; plumage softer and pattern slightly blended. Young female: Like young male, but red of crown somewhat reduced." C. Distinguishing characteristics Interspecific - Peterson (1969) ,"Nuttall ' s Woodpecker is found only in California, west of Sierra, not in the desert. There are minor differences in the amount of black on upper back, pattern on face. Downy Woodpecker has white back. Robbins, Bruun, Zim (1966), r,Told from Gila and Golden- fronted by the dark rump, finely spotted sides, and lack of white wing patch in flight." Udvardy (1977), "Zebra- backed like Nuttall1 s Woodpecker, but with slightly smaller black ear patch and face stripe, usually separated from black of nape and back of white band. Male s red cap usually more extensive than Nuttall' s." •♦ Picoides scalaris cactophilus (con't.) A Intraspecific - Bent (1939), "Much like D. _s. eremicus, but J smaller, particularly the tail and bill; lower surface lift- er, laterally almost always streaked with black; upper parts lighter - the black bars on back and scapulars narrower; wing quills with larger spots and broader bars on white; outer long rectrices with exterior webs barred throughout with black; black bars on posterior lower surface narrower." As compared with D. _s. symplectus, "slightly larger, with black bars on back, etcT, decidedly broader." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) in describing P. scalaris, "From southeastern California, southern Nevada, southwestern Utah, and southern Colorado south through Mexico (including Baja California, the Tres Marias Islands and Cozumel Island, Quintana Roo) to Chiapas and British Honduras." AOU (1957) in describing P. _s. cactophilus. "Resident in the desert areas of southeastern California, southern Nevada, southwestern Utah, central Arizona, central New Mexico, and western Texas, south to the Colorado River Delta, in north- eastern Baja California, to about lat. 20°N. in Sonora (in- a eluding Tiburon Island), Chihuahua and northern Durango." B. California distribution of the species Grinnell and Miller (1944), lists numerous site and specimen records throughout the birds' California range. States, in general, Colorado and Mojave deserts. Life- zone, Lower Sonoran, Small (1974), "Colorado and Mohave deserts." Miller (1951) gives locations. Bendire (1895) reported that a mated pair was found in San Gorgonio Pass and also some in the Colorado desert. C. California desert distribution Grinnell and Miller (1944), "Colorado and Mojave deserts" Lower Sonoran life-zone. Small (1974) also give this. Grinnell (1902) reported them as common to deserts of the southeastern corner of California, recorded west to Hesperia and San Gorgonio Pass. Grinnell (1915) reported them as a "common resident locally on the Lower Sonoran deserts of southeastern California," and goes on to give various localities. Willett (1933) gives locations, especially in the Colorado Desert. Bent (1939) reports that this species frequents the deserts or borders of deserts and lower slopes of the mountains in the Sonoran Zone. Dawson (1923), "The southeastern deserts, broadly; hence, occasionally invading Picoides scalaris cac tophi lus (con't.) the domain of nuttalli through Walker and San Gorgonio Passes." Carter (1937) reported them at Twentynine Palms. Hoffmann (1922) found them near Banning. D. Seasonal variations in distribution IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), "Almost any kind of desert terrain providing fair- sized shrubby vegetation and also diggable woody stems or trunks of sufficient diameter for nesting excavations. . .commonly by the trunks of tree-yucca ...cottonwood and willow. . .also telegraph poles." Small (1974), "Low and high deserts, pinon- juniper woodlands." Found also in desert scrub. Miller (1951) found them in the Lower Sonoran areas, desert scrub, pinon- juniper forma- tions and riparian woodlands. Peterson (1969;, "Deserts, canyons, cottonwoods, arid brush, Bruun, Zim (1966), "Fairly common mesquite, less common in cactus." and their borders; also mesquite, and scrub oaks." Bendire (1895), and river bottoms." prairie groves." Robbins, in deciduous woods and Udvardy (1977), "Deserts pinon- juniper woodland, It prefers the lowlands B. Altitudinal range Grinnell and Miller (1944) states that they are found from 200 feet below sea level to 6,000 feet and up to 6800 feet as a vagrant. Bendire (1895), "...rarely found at alti- tudes above 4000 feet." C. Home range size D. Territory requirements Perch sites Courtship and mating sites Nest sites - Grinnell and Miller (1944) state that almost any type of desert terrain containing fair- sized shrubby vegetation and diggable woody stems or trunks of sufficient diameters will do. Bent (1939) repeats findings of nests being from 2-30 feet off the ground in cavities in various wooden structures and plants. Peterson (1969), "In hole in tree, post, yucca, agave." Udvardy (1977), "...in the tall (up to 30 feet high) dry stalk of a century plant or agave; occasionally in a hole chiseled in a yucca, a cotton- wood tree, or even a fence post." Dawson (1923), "Nest: A ff • ♦ ♦ Picoides scalaris cactophilus (con't.) hole at moderate height in giant cactus, Joshua- tree, willow, or other tree." Also, the dried stalks of the agave and lesser yucca and willows, as well as mesquite and telephone poles. Bendire (1895), reported that it prefers mesquite trees. E. Special habitat requirements Dawson (1923), "...requires something of more ample girth for a nesting site (than creosote or cholla). F. Seasonal changes in habitat requirements V FOOD A. Food preferences Bent (1939) reports larvae of woodboring beetles, coddling moths, and other Lepidoptera. Udvardy (1977) reports larvae of the agave beetle. Dawson (1923) reported that they eat the ripened fruit of the giant cactus. Bendire (1895) reports this also. B. Foraging areas Grinnell and Miller (1944) state that foraging occurs in trunks of the tree-yucca, trunks or dead flower stalks of other yuccas, cottonwood and willow trunks, telegraph poles, cactus clumps, various bushes and desert trees such as mesquite, palo verde, and ironwood. Udvardy (1977) reports century plant flower stalks. Austin (1978) has found that males and females forage in different areas (on different species of plants) , and that the species they feed on change during the year. Females feed mainly on mesquite throughout the year, while males switch between cholla, mesquite, and others. C. Foraging strategies Bent (1939) reports that it gleans larvae from trunks and branches of trees, usually at low elevations on small trees, shrubs, cacti. Also, it sometimes feeds on the ground. D. Feeding phenology E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior r Picoides scalaris cactophilus ( con ' t . ) C. Courtship and mating behavior D. Nesting phenology Dawson (1923), "Season: March 25-May, rarely June." Bendire (1895), "...full sets of fresh eggs are sometimes found by the middle of April... but (usually) the first week of May." E. Length of incubation period Bendire (1895), "about 13 days." F. Length of nestling period G. Growth rates H. Post-breeding behavior Dawson (1923), "One brood." Bendire (1895), one brood, rarely two, maybe. VII POPULATION PARAMETERS A. Clutch size Bent (1939) gives clutch size as 2-6 eggs, usually 4 or 5. ^ Peterson (1969), and Udvardy (1977), say 4 or 5. Dawson (1923), usually 4. Bendire (1895), 2-5, usually 4 or 5. B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abundance Bendire (1895), reports gregariousness in winter. In December, 1885, flocks of 4-12 birds were encountered fre- quently at 3,000 feet. F. Habitat density figures Bendire (1895) reported flocks of 4-12 on plains at 3,000 feet in December, 1885. VIII INTERSPECIFIC INTERACTIONS A. Predation e Picoides scalaris cac tophi lus ( con ' t . ) | B. Competition Bent (1939) reports that in the regions where it is found, there are no other species of woodpecker. Gila Woodpeckers and Mearn's Gilded Flickers replace it in giant cactus (Saguaro) regions. Short (1971) saw conflicts between these and Nuttall's Woodpeckers. C. Parasitism IX STATUS A. Past population trends Grinnell (1902) reported them as "common resident in deserts of southeastern corner of the State." Grinnell (1915) reported them as a "common resident locally on the Lower Sonoran deserts of southeastern California." Willett (1933) reported them as a common resident of the Colorado Desert west to San Gorgonio Pass. B. Present population status ♦ Grinnell and Miller (1944) reported that they are permanently resident and common with the degree of abundance dependent on availability of nest sites. Small (1974) reported them as resident. C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status # Picoides scalaris (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American Birds. 5th Ed. American Ornithologists' Union. The Lord Baltimore Press, Inc. Baltimore, Maryland. 691 pp. Austin, G. T. 1976. Sexual and seasonal differences in forag- ing of Ladder-backed Woodpeckers. Condor 78(3) : 317-323. Bendire, C. 1895. Life Histories of North American Birds. Volume 2. Smithsonian Contributions to Knowledge #985. Smithsonian Institution. Washington, D.C. 518 pp. Bent, A. C. 1939. Life Histories of North American Woodpeckers. Smithsonian Institution. United States National Museum Bulletin #174. U.S. Government Printing Office. Washington, D.C. 334 pp. Carter, F. 1937. Bird life of Twentynine Palms. Condor 39: 210-219. Dawson, W. L. 1923. The Birds of California. Volume Two. South Moulton Company. San Diego. 1432 pp. Grinnell, J. 1902. Checklist of California Birds. Pacific Coast Avifauna #3. Cooper Ornithological Club. Santa Clara, California. 98 pp. Grinnell, J. 1915. A distributional list of the Birds of California. Pacific Coast Avifauna #11. Cooper Ornith- ological Club. Hollywood, California. 317 pp. Grinnell, J. and A. H. Miller. 1944. The distribution of the Birds of California. Pacific Coast Avifauna Number 27. Cooper Ornithological Club. Berkeley, California. 608 pp. Hoffmann, R. 1922. Field notes from Riverside and Imperial Counties, California. Condor 24:101. Miller, A. 1951. An analysis of the distribution of the birds of California. University of California Publications in Zoology. Vol. 50, #6, pp. 531-644. Morony, J. J., Jr., W. J. Bock, J. Forrand, Jr. 1975. Refer- ence list of the birds of the world. The American Museum of Natural History. New York. 207 pp. Oberholser, H. C. 1911. A revision of the forms of the Ladder- backed Woodpecker (Dryobates scalaris ^WoglerJ ) . Proc. U.S. Nat. Mus., vol. 41, pp. 139-lW. c <* Picoides scalaris (con't.) Peters, J. L. 1948. Checklist of birds of the world. "Vol. VI. Howard University Press. Cambridge, 259 pp. Peterson, R. T. 1969. A field guide to western birds. Houghton Mifflin Company. Boston. 366 pp. Ridgway, R. 1914. The birds of North and Middle America. Part VI. Bull, of the U.S. Nat'l Museum. Gov't. Printing Office. Washington, D.C. 882 pp. Robbins, C. S. , B. Bruun, H. S. Zim. 1966. Birds of North America. Western Publishing Company, Inc. Racine, Wiscon- sin. 340 pp. Short, L. L. 1971. Systematics and behavior of some North American Woodpeckers, Genus Picoides (Aves). Bulletin of the American Museum of Natural History. Vol. 145: Article 1, pp. 1-118. Small, A. 1974. The birds of California. Winchester Press. New York. 310 pp. Udvardy, M. 0. F. 1977. The Audubon Society Field Guide to North American Birds. Alfred H. Knopf, Inc. New York. 855 pp. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna #21. Cooper Ornitholo- gical Club. Los Angeles, California. 204 pp. £ « LAWRENCE'S GOLDFINCH Carduelis lawrencei I TAXONOMY A. Type description AOU (1957) Spinus lawrencei: Carduelis lawrencei Cassin, Proc. Acad. Nat. Sci. Philadelphia, no. 3^ Sept. -Oct. (Dec. 7), 1850, p. 105, pi. 5. (Sonoma and San Diego, Calif- ornia. ) B. Current systematic treatments Mayr (1968), recognizes C. lawrencei as a monotypic species in a genus in which there are twenty- four species. Passeri- formes: Fringillidae (Carduelinae) . C. Synonomies of scientific nomenclature Dawson (1923), Astragalinus lawrencei. Small (1974), Spinus lawrencei. Grinnell and Miller (1944) , Chrysomitris lawrencei; C. lawrencii; Astragalinus lawrencii. D. Synonomies of vernacular nomenclature DESCRIPTION A. External morphology of adults Dawson (1923), "Adult male in spring: General color neutral gray, paling on underparts posteriorly; pileum, face, and throat, narrowly, black; breast dark yellow..., everywhere sharply outlined against the surrounding gray; rump yellow; back touched with yellow centrally; the wings black, heavily edged with yellow; the tertials bordered with white; tail black, the three or four outermost pairs of feathers heavily blotched with subterminal white on inner web. Bill light; feet brownish. Adult male in autumn: as in spring, but back and sides of hind neck brownish olive. Adult female in spring: Like male in spring but without black on head and throat; duller. In autumn: Above brownish olive." Ridgway (1901), detailed description of adult male and female, including plumage, soft parts, and measurements. Peterson (1961), yellow wing-bars. Male: Gray-headed, with black face. . . ; some yellow on breast and rump. . .No seasonal change. Female: Lacks black face. Gray color, 2 yellow wing bars. » Carduelis lawrencei (con't.) B. External morphology of subadult age classes Dawson (1923), "Young birds are like adult female in autumn, but yellow element is almost or quite confined to wing, where also largely replaced by buffy brown edgings; breast faintly streaked. ' Ridgway (1901), "Similar to adult female, but colors duller, with yellow, especially on breast, less distinct, and under parts obsoletely streaked." C. Distinguishing characteristics Interspecific - Peterson (1961), "only U.S. goldfinch with a black chin. ..2 yellow wing-bars distinguish it (female) from other goldfinches." Intraspecific - III GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), "Breeds in California west of the Sierra Nevada (Hyampom southeast to Santa Rosa Mountains) and in northern Baja California (Sierra Juarez, Sierra San Pedro Martir) . Dawson (1923), "California and northern Lower California; in winter east to Arizona (but chiefly at Colorado Valley points) and New Mexico (Fort Bayard). ' Ridgway (1901), 'California and northern Lower California (breeding south to San Pedro Martir Mounta'ins) ; in winter to Arizona." B. California distribution of the species Dawson (1923), "Of very local occurrence in summer west of the Sierras, perhaps chiefly in the southwestern coast districts, but also north through Great Valley to McCloud River, in Shasta County and east to Weldon, Kern Co., Raymond, Madera Co., and Oroville, Butte Co.; breeding, chiefly in Upper Sonoran life zone; perhaps casual breeder in Lower Sonoran (Indian Wells, Colorado Desert...). Per- haps casual on Catalina Island, but a regular breeder on Santa Cruz Island." Small (1974), "West of Cascades and Sierra Nevada and south of the northern mountains; coast- wise (from about Sonoma County) and interiorly south through Central Valley to Mexican border." C. California desert distribution Grinnell and Miller (1944), "Breeds in coastal districts from Sonoma County south to Mexican boundary and interiorly, west of Cascade- Sierran axis, from Shasta and Trinity counties southward; extends eastwardly through mountains of southern r Carduelis lawrencei (con't.) j California onto western edge of Mohave Desert in vicinity of Victorville. . . In winter... in moderate numbers in coastal southwestern California and in Coachella, Imperial, and Colorado River valleys." Recorded at following sites: Weldon and Mt. Pinos, Kern Co. ; Hesperia, Grapevines, and Twentynine Palms, San Bernardino Co.; Azusa, Los Angeles, and Pasadena, Los Angeles Co.; Escondido, Volcan Mts., and San Diego, San Diego Co.; Mecca, Riverside Co.; March and the Alamo River near Brawley, Imperial Co. Carter (1937), noted several among the Lesser Goldfinches at Twentynine Palms. Miller (1951), Kern Basin and San Diego. D. Seasonal variations in distribution AOU (1957), "Winters from north-central California (San Francisco, Margsville) , central Arizona (Fort Mohave, near Prescott, Phoenix, Paradise), and southwestern and central southern New Mexico (Fort Bayard, Las Cruces) south to northern Baja California (20 miles south of San Quintin, Cocopah Mountains), northern Sonora (Tecoripa), and western Texas (El Paso). Dawson (1923), "Winters irregularly in San Diego district and east of the desert divide to the Colorado River." Grinnell and Miller (1944), "Summer resi- dent from April through September. A small part of the population remains through winter in the breeding range; I also appears then in otherwise unoccupied areas southeast- r wardly/' IV HABITAT A. Biotopic affinities Peterson (1961), "open oak or oak-pine woods, dry chaparral, edges." Small (1974), "riparian woodland, oak woodland, open forest, montane forest of a more arid nature, pinon- juniper woodland." Grinnell and Miller (1944), "as breeding, usually oak woodland and open or broken forest of the arid Transition Zone. Coutlee (1968), "restricted to wooded areas bordering permanent water sources." Miller (1951), Upper and Lower Sonoran and Transition life zones. B. Altitudinal range Grinnell and Miller (1944) "nesting stations extend(s) from near sea level as at Laguna Beach, Orange County, up to 6500 feet, as in the San Bernardino Mountains; vagrants have been taken up as high as 8500 feet." » Home range size Coutlee (1966), reports territories about 10-15 meters in diameter. Car duel is lawrencei (con't.) D. Territory requirements \ Perch sites - Jaeger (1947), "on creosote twigs." Gander (1930) "Some fifty or more roosted nightly in a large clump of lemonade berry bush (Rhus integrifolia) in the center of a grassy patch in a nearby canyon" (January and February, East San Diego). Coutlee (1968) 'singing loudly from the tops of the trees." Linsdale (1950), "the whole flock would fly up to a fence or to a nearby, isolated blue oak." Courtship and mating sites - Nest sites - Dawson (1923), "A rather loosely woven cup of highly varied materials, --grasses, wool, weed- stems, and feathers; placed at any height in a cypress tree, or at moderate height (2 to 15 feet) in weeds, artemesia, elder- berry bush, or small tree, as live oak." E. Special habitat requirements Grinnell and Miller (1944), "Water sources probably are necessary." Linsdale (1950), "Birds that feed so exclu- sively on dry seeds as the goldfinches do apparently have greater need for water to drink than other kinds. Between feeding periods they assemble at watering places where they drink, sing, bathe, preen, rest, and sun themselves." ^ F. Seasonal changes in habitat requirements Linsdale (1950), "We see the species in winter in the chamisal and where there is water along intermittent creeks. In spring it ranges over open ground where abundant small seeds are produced. In the nesting season the birds go to the hills where there are oaks. Linsdale (1957), "Search for particular kinds of seeds takes the bird to varied kinds of habitat." V FOOD A. Food preferences Culbertson (1946) reports birds feeding on seed fleas or jumping galls (Neuroterus slltatorius) . Examination of droppings of the birds revealed only the hulls of the galls, suggesting that the birds feed only upon the insects inside. Ortega (1945), observed feeding on one egg of two in a Mourning Dove's nest. Gander (1930), "seen feeding daily on the seeds of the greasewood ( Ad eno stoma fascicu- latum) . " Linsdale (1950) 'special predilection for seeds of the Boraginaceae." Coutlee (1966) 'feed almost exclusively on seed-bearing chaparral plants, although a few insects ^^ (mostly Aphidae) may be taken during the breeding season." Carduelis lawrencei (con't.) J B. Foraging areas Grinnell and Miller (1944), "Grassland, growths of tall annuals, and chaparral are plant formations where suitable and workable seed supplies may be found, often at some distances from the nest." Linsdale (1957) "It is fitted to live where the seeds it eats and the water it requires may be far from the trees where it nests." C. Foraging strategies Linsdale (1957) "They search in flocks for patches of low herbaceous plants and shrubs that bear seeds." D. Feeding phenology E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Dawson (1923), "colonize to some extent. .. found as many m as ten nests at once in two adjoining trees." Coutlee (1966), "is much less active in his defense than is the male psaltria. He often sings while perched near the nest when he comes to feed the female. No elaborate circling flight displays or song flights are given... The territory is usually defended solely by high intensity singing if a strange male enters it. In only a few instances was a resident Lawrence's male seen to fly toward a strange male." Includes detailed analysis of vocalizations and comparisons with C. psaltria. Linsdale (1950), reports incidents where resident males did chase: "The male was quick to chase other males. The female pursued other females and sometimes strange males. " C. Courtship and mating behavior Coutlee (1968), "initially large flocks. . .break up as each male becomes less tolerant of other males and spends more and more time singing loudly from the tops of the trees... Noisy groups of five or six individuals are common in the tops of oaks" (mixed males and females). Coutlee (1966), "The male lawrencei are subordinate to the females and approach them only hesitantly. .. It is... the female who initiates billing and courtship feeding by flying to and perching near the male. . .Feeding of the female by the male is continued throughout nesting. Coutlee (1971), detailed analysis of vocalizations. Carduelis lawrencei (con't.) D. Nesting phenology Dawson (1923), "Extreme dates: Shandon, April 8, 1916, 5 fresh eggs; Claremont, July 5, 1903, 4, inc. begun... In the more elevated stations of southern California, the seasons may be prolonged into June, or even July." E. Length of incubation period Coutlee (1966), "The female is in almost continuous attendance of the nest during the 12-13 days of incubation." Shepardson (1915), "lasts from ten to twelve days." F. Length of nestling period Linsdale (1950), "the young birds hatched on July 2... they left on the 13th or 14th day after hatching." Coutlee (1966), "The young remain in the nest for 12-15 days before fledging." Shepardson (1915), "the young birds remain in the nest about two weeks." Linsdale (1957), description of nestling period up to 11 days after hatching, whereupon the young fledged. G. Growth rates Coutlee (1966), description of the development of vocal- izations and motor patterns in hand-reared birds. H. Post-breeding behavior Coutlee (1966), "By the end of the first week or so after fl edging. .. the young birds accompany the adults to foraging areas and are fed whenever they give the insistent begging calls. These small family groups do not return to the nesting territory and remain together until the end of the season when large flocks are again formed as migration begins." VII POPULATION PARAMETERS A. Clutch size B. Fledging success C. Mortality rates per age class D. Longevity Carduelis lawrencei (con't.) W E. Seasonal abundance Culbertson (1949), "a flock of about thirty continued to appear everyday" (August, Fresno, California). Gander (1930), reports small flocks of from eight to twenty, January and February, East San Diego. Linsdale (1950), "From 50 to 200. . .were present daily for nearly a month, beginning in the middle of March." Coutlee (1966), "Both the Lesser and Lawrence's Goldfinches are highly social and form loose flocks of 20-30 birds during the non- reproductive season. . .May include members of both species of goldfinches or even of other passerines." F. Habitat density figure Dawson (1923), "found as many as ten nests at once in two adjoining trees." VIII INTERSPECIFIC INTERACTIONS A. Predation ♦ Coutlee (1968), "Jays, squirrels, and cowbirds were chased from nest sites." B. Competition Coutlee (1966), "Since nest sites are often similar in both species (C. lawrencei and C. psaltria) , some interspecific competition is apparent." C. Parasitism Friedmann (1943), reports one nest containing four eggs of the goldfinch and one of the Dwarf Cowbird (Gilroy, Calif- ornia) ; another clutch containing one egg of the goldfinch and two of the cowbird (collected in Ventura Co., California). IX STATUS A. Past population trends Grinnell and Miller (1944), "Fairly common in general, but numbers often variable from year to year in any given locality, and distribution notably discontinuous and movements erratic. ' Willett (1912), "Common summer resident of the mesas and foothills up to 7000 feet... Rare in winter." Carduelis lawrencei (con't.) B. Present population status Small (1974), "resident in southern half of the state; summer visitor elsewhere." Linsdale (1950), "the population of Lawrence Goldfinches is greater now than it was before the development of agriculture in its range and that probably its range has been extended somewhat by that development." C. Population limiting factors Linsdale (1950), "the kind and amount of seeds produced each year are important in determining the numbers of goldfinches and the length of their stay." D. Environmental quality: adverse impacts E. Potential for endangered status * Carduelis lawrencei (con't.) I LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39:211-219. Coutlee, E. L. 1966. The comparative behavior of Lawrence's and Lesser Goldfinches. Ph.D. Thesis Univ. Claifornia, Los Angeles. Coutlee, E. L. 1968. Comparative breeding behavior of Lesser and Lawrence's Goldfinches. Condor 70:228-242. Coutlee, E. L. 1971. Vocalizations in the genus Spinus. Animal Behavior 19:556-565. Culbertson, A. E. 1946. Lawrence Goldfinches feed on jump- ing galls. Condor 48:40. Dawson, W. L. 1923. The birds of California. South Moulton Co., San Francisco. Friedmann, H. 1943. Further additions to the list of birds known to be parasitized by the cowbirds. Auk 60:350-356. Gander, F. F. 1930. Notes on winter bird roosts. Condor 32:64. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. Jaeger, E. C. 1947. Use of creosote bush by birds of the southern Calif ornian deserts. Condor 49:126-127. Linsdale, J. M. 1950. Observations on the Lawrence Goldfinch. Condor 52:255-259. Linsdale, J. M. 1957. Goldfinches on the Hastings Natural History Reservation. Amer. Midi. Nat. 57:1-119. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. Vol. 50, No. 6. Ortega, J. L. 1945. Lawrence Goldfinch eating egg of Mourning Dove. Condor 47:41. 10 Carduelis lawrencei (con't.) Peters, J. L. 1968. Checklist of birds of the world. Vol. 13. (E. Mayr, ed. ) Mus. Comp. Zool. , Cambridge, Massachu- setts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. Ridgway, R. 1901. The birds of North and Middle America. Part 1. U.S. Natl. Mus. Bull. No. 50. Shepardson, D. I. 1915. Nesting habits of Lawrence's Gold- finch. Oologist 32:58-60. Small, A. 1974. The birds of California. Macmillan Co., New York. Willett, G. 1912. Birds of the Pacific slope of southern California. Pacific Coast Avifauna No. 7. LESSER GOLDFINCH w Carduelis psaltria I TAXONOMY A. Type description AOU (1957), Spinus psaltria hesperophilus ; Astragalinus psaltria hesperophilus Oberholser, Proc. Biol. Soc. Washing- ton, 16, Sept. !v, 1903, p. 116. (San Bernardino, Calif- ornia. ) B. Current systematic treatments Mayr (1968), recognizes twenty- four species in the genus Carduelis; five subspecies in the species psaltria (witti, hesperophila, psaltria, j ouyi , columbiana) . Pas seri formes: Fringillidae (Carduelinae) . C. Synonomies of scientific nomenclature Dawson (1923), Astragalinus psaltria hesperophilus. Peter- son (1961), Spinus psaltria. Grinnell and Miller (1944), Chrysomitris psaltria; C. mexicanus; also under subspecies ari zonae. | D. Synonomies of vernacular nomenclature Dawson (1923), Green-backed Goldfinch. Peterson (1961), Dark-backed Goldfinch. Grinnell and Miller (1944), Arkansas Siskin; Western Goldfinch; Arkansas Finch; Arkansas Gold- finch; Mexican Goldfinch; Arizona Goldfinch. II DESCRIPTION A. External morphology of adults Dawson (1923), "Adult male (no seasonal change): Pileum, broadly, glossy black; sides of head and upper parts olive- green, .. .more yellow on rump, sometimes faintly streaked with darker, or blackish, on back; upper tail-coverts chiefly black; wings black; the middle and greater coverts and tertials (variably) tipped with white; both webs of inner primaries crossed about midway with white, forming a conspicuous blotch in flight; tail black, the two or three outermost pairs of feathers extensively white on inner web; underparts lemon-yellow, paling posteriorly, shading on sides. Bill horn-color; feet and legs brownish. Adult female: Like male but much paler and duller, without black. Above dull olive ...; below olive-yellow, paling posteriorly." Peterson (1961), "Male: a very small finch with a black cap, black or greenish backs and bright yellow underparts; bold white marks on wings. The black cap is retained in winter. . .Female: Very similar to female American Goldfinch but smaller, more greenish; had dark rump." Carduelis psaltria ( con ' t . ) B. External morphology of subadult age classes Dawson (1923), "Immature males are like adult females but brighter, with early indications of black cap." C. Distinguishing characteristics Interspecific - Dawson (1923), "coloration not definitely gray, and chin not black, as distinguished from A. (G.) lawrencei . " Peterson (1961), "The black cap is retained (by males) in winter (male Americans become brownish and lose caps) .. .American Goldfinch always shows white near rump. Summer male has yellow back." Intraspecific - III GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), Spinus psaltria in general: "Southwestern Washington, western Oregon, northeastern California, northern Nevada, northern Utah, northern Colorado, northwestern Okla- homa, and central Texas south through Mexico, Central America, and northwestern South America to northwestern Peru, central Colombia (San Agustin) , and northern Venezuela. Introduced in western Cuba (Habana, Banza) . " C. p_. hesperophilus : "Resident from southwestern Washington (Vancouver) , western Oregon (Portland; Coos County), northeastern California (Modoc County), northern Nevada (Santa Rosa Mountains), and northern Utah (Tooele, Morgan, and Uintah Counties) south through California and central Arizona (Flagstaff, Grand Canyon) to southern Ban a California (Sierra de la Laguna) and southern Sonora (Guirocoba) , Casual to eastern Oregon (Riverside), south-central New Mexico (San Antonio), and northwestern Durango." Dawson (1923), C. p^ hesperophilus "Southwestern United States from central northern Texas, northern Colorado, southern Idaho, and southern Oregon, south through Mexico to northern South America." B. California distribution of the species Dawson (1923), C. p_. hesperophila: "An abundant breeder below the Transition zone and locally within that zone; most abundant along the southern coasts and in the central interior; rare or wanting in the humid Northwest; apparently absent from the central region east of the Sierras, at least above the head of Owens Valley and its tributaries (White Mountains above Bishop. . . , Hilton Creek, Long Valley. . . , near Mammoth Camp...), although reappearing in Lassen and Humboldt Counties (Goose Lake. . . , Surprise Valley. . . , Eagle- ville...); of local distribution in the deserts; of limited # • Carduelis psaltria (con't.) occurrence on some of the Santa Barbara Islands (Santa Cruz) and casually on the Farallons." Grinnell and Miller (1944), "The entire State, except small districts in high mountains and heavily timbered areas; may appear even in such places as a vagrant, especially in late summer. Most abundant and most continuously distributed in southern and central California west of the Sierra Nevada." C. California desert distribution Dawson (1923), "of local distribution in the deserts." Grinnell and Miller (1944), recorded in following areas: Buena Vista Lake, south fork of Kern River, and Walker Basin, Kern Co. ; Los Angeles, Los Angeles Co. ; Cabezon, Riverside Co. ; Escondido and San Diego, San Diego Co. ; Inyo, Panamint, Grapevine and Argus Mountains, Owens and Death Valleys, Inyo Co.; Mecca, Riverside Co. Carter (1937), reports various sized flocks and individuals often observed at Twentynine Palms, California. Miller (1951), Kern Basin, San Diego, Inyo, Modoc, Mojave regions and Channel Islands. D. Seasonal variations in distribution Grinnell and Miller (1944), "probably leaves northeastern section in winter." Willett (1912), "Abundant summer resi- dent of the Mesa and foothill regions and up to 3000 feet in the mountain canyons. Less common in the lower country and up to 6400 feet in the mountains. In winter, distributed in flocks over the whole lower country." IV HABITAT A. Biotopic affinities Small (1974), "riparian woodland, open forest, savannah, open areas with trees nearby." Peterson (1961), "open brushy country, open woods, wooded streams, gardens." Grinnell and Miller (1944), "Open terrain with scattered trees or bushes. Brush land may be occupied if open land and edge situations are present in the vicinity. Of the four members of the genus Spinus , . . . shows the widest range of tolerance with respect to rainfall, humidity and temper- ature. It appears to be the most water- seeking of all the gold finches. Miller (1951), Lower and Upper Sonoran and Transition life zones. Coutlec (1966), breed mainly in chaparral and oak woodland. . .Found in dry chaparral to distances of as much as one-half mile from water." Linsdale (1957), "In the dry seasons these birds concentrate about supplies of water in streams and springs." # Carduelis psaltria (con't.) E. Altitudinal range 4P Grinnell and Miller (1944), "extends from -200 feet at Mecca, Riverside County, up to 9800 feet on Mount Tallac, Eldorado County; probably does not breed much above 6500 feet, as in San Bernardino Mountains and at Mono Lake." Dixon (1943), one observed in September, Kings Canyon National Park, at 11,000 feet. C. Home range size Coutlee (1966), reports territories about 30 meters in diameter. D. Territory requirements Perch sites - Jaeger (1947), "on creosote twigs." Coutlee (1968), "stations himself near the top of a tall tree and makes himself conspicuous by perching in the open and utter- ing occasional short songs. Courtship and mating sites - Coutlee (1968), "As courtship progresses, the following flights develop into high- inten- sity chasing flights, the male following the female at a distance of two meters or less and the two birds darting rapidly in and out through dense foliage." Mb Nest sites - Dawson (1923), "Placed at any height but usually moderate, and in almost any host, --tree or bush or even rank weeds; live oaks and sycamores favorites; ... of twisted grasses and weed fibers, deeply capped, lined with fine grasses or horsehair; settled firmly into concealing bunch of leaves or branching twigs, or sometimes artfully incorpor- ated with immediate setting." E. Special habitat requirements Linsdale (1957) "Availability of water is important in the nesting season and afterward when water becomes scarce. The distribution of water helps determine where the gold- finches live." F. Seasonal changes in habitat requirements V FOOD A. Food preferences Dawson (1923), "96 per cent. .. consists of weed- seed. . .Napa Thistle. Gander (1929), reports feeding on seeds of various species of Eucalyptus in Balboa Park, San Diego. Coutlee (1966) "feed almost exclusively on seed-bearing chaparral Carduelis psaltria (con't.) plants, although a few insects (mostly Aphidae) may be taken during the breeding season." Linsdale (1957), "plant materials, including buds, leaves, fruits, and seeds. " B. Foraging areas Grinnell and Miller (1944), "Activity centers near the ground in foraging- -on low-growing composites, for example, the seed heads on bush tops; seldom, as with the American Goldfinch and Pine Siskin, does it feed in the crowns of trees. " C. Foraging strategies Dawson (1923), Napa Thistle: "cracks each brittle shell and, aided no doubt by its tongue, extracts. .. the starchy kernel." Ross (1924), "while seeding a batchelor button head, bent the slight stem to a horizontal position. When through with it, the bird reached deliberately out with one foot and grasped a nearby spray and pulled it under his feet on the original stem and ate from the new supply of seeds." Linsdale (1957), "forage in flocks through most of the year. They move through the bushes and trees that provide the major part of their food, and they sometimes t concentrate on the lower herbaceous plants." D. Feeding phenology E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Coutlee (1966), "he perches atop the highest branches of the trees within his territory. . .and gives very loud ad- vertising song. . .Although given at fairly regular intervals throughout the day, song is characteristically triggered by song from other males or the presence of another male near the territory. If a strange male enters the territory, the resident male flies toward it with the ' song flight display'." Includes detailed analysis of vocalizations and comparisons with _C. lawrencei . Carduelis psaltria (con't.) C. Courtship and mating behavior Coutlee (1966), "small flocks broke up into pairs over a period of only one week. After this time they were found perching or flying in pairs, the male and female usually about a meter apart. . .Repeated chasing between the two members of a pair. .. characterizes the initial stages of courtship. . .This, in turn is replaced by 'billing as members of the pair become more tolerant of one another. . . Billing develops into true 'courtship feeding' in which the female actually takes regurgitated food from the males bill. . .Feeding of the female by the male is continued throughout nesting." Coutlee (1971), detailed analysis of vocalizations . D. Nesting phenology Dawson (1923), "April to June, or occasionally in autumn; two or three broods." Grinnell and Miller (1944), "In south and west-central California, occasionally nests in fall." E. Length of incubation period Dawson (1923), "lasts eleven or twelve days." Coutlee (1966) "continuous incubation is begun before the clutch of three to five eggs is complete. .. the female is in almost continuous attendance at the nest during the 12-13 days of incubation. " F. Length of nestling period Coutlee (1966), "the young remain in the nest for 12-15 days before fledging. ' G. Growth rates Coutlee (1966), description of development of vocalizations and motor patterns in hand-reared birds. H. Post-breeding behavior Coutlee (1966), "By the end of the first week or so after f ledging. . . the young birds accompany the adults to foraging areas and are fed whenever they give the insistent begging calls. These small family groups do not return to the nesting territory and remain together until the end of the season when large flocks are again formed as migration begins. " Carduelis psaltria (con't.) [I POPULATION PARAMETERS A. Clutch size Dawson (1923), "4 or 5, ovate, pale bluish green, unmarked." B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abundance Dawson (1923), after Carpodacus mexicanus, "possibly the most abundant numerically of the breeding birds of central and western California. . .about thirty million of them per annum in California." Carter (1937), "around April 27, 1934, flocks of 2 or 3 dozen frequented beds of a small yellow composite in the swamp." Coutlee (1966), "Both the Lesser and Lawrence's Goldfinches are highly social and form loose flocks of 20-30 birds during the non- reproductive season. . .May include members of both species of goldfinches or even of other passerines." F. Habitat density figures Gaines (1974), reports 35 and 43 territorial males per square kilometer in clumped cottonwood and willow woodland, Butte County, 1972 and 1973, respectively. VIII INTERSPECIFIC INTERACTIONS A. Predation Coutlee (1968), "On one occasion a Cooper's Hawk called and alighted in an area where psaltria nests were abundant. About 20 psaltria gathered in a loose flock about the hawk- -both in the same tree and in adjacent trees--and gave continual, drawn-out Hawk calls. . .Jays, squirrels, and cowbirds were chased. . .usually both male and female participating. " B. Competition Coutlee (1966), "There is some competition for nest sites (with C. lawrencei) probably due in part to the highly social nature of both species and their attraction to nest building activities." • • Carduelis psaltria ( con ' t . ) C. Parasitism Piath (1919), reports an average of 61% of the nests examined held young infested with larvae of Protocaliphora azurea; a total of 13 nests examined. Woods (1930) , "founaT. . incubating three of its own eggs and one of the cowbird's (Molothrus a tea) . The eggs were later abandoned before they had hatched . " IX STATUS A. Past population trends Grinnell and Miller (1944), "Resident, but there is consid- erable local movement and vagrancy. .. common to abundant." B. Present population status Small (1974), breeding resident. C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status ♦ Car due lis psaltria (con't.) LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39: 211-219. Coutlee, E. L. 1966. The comparative behavior of Lawrence's and Lesser Goldfinches. Ph.D. Thesis, U. California, Los Angeles. Coutlee, E. L. 1968. Comparative breeding behavior of Lesser and Lawrence's Goldfinches. Condor 70:228-242. Coutlee, E. L. 1971. Vocalizations in the genus Spinus. Animal Behavior 19:556-565. Dawson, W. L. 1923. The birds of California. South Moulton Co. , San Francisco. Dixon, J. S. 1943. Birds of the Kings Canyon National Park area of California. Condor 45:205-219. Gaines, D. 1974. A new look at the nesting riparian avifauna of the Sacramento Valley, California. Western Birds 5: 61-80. Gander, F. F. 1929. Notes on the food and feeding habits of certain birds. Condor 31:250-251. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. Jaeger, E. C. 1947. Use of creosote bush by birds of the southern Californian deserts. Condor 49:126-127. Linsdale, J. M. 1957. Goldfinches on the Hastings Natural History Reservation. Amer. Midi. Nat. 57:1-119. Peters. J. L. 1968. Checklist of birds of the world. Vol. 10. (E. Mayr, ed. ) Mus. Comp. Zool. , Cambridge, Massachu- setts. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool., Vol. 50, No. 6. Peterson, Ri T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. 10 Carduelis psaltria (con't.) Plath, 0. E. 1919. Parasitism of nestling birds by fly larvae. f Condor 21:30-38. Ross, R. C. 1924. More birds that grasp objects with the feet. Condor 26:226-227. Small, A. 1974. The birds of California. Macmillan Co., New York. Willett, G. 1912. Birds of the Pacific slope of southern California. Pacific Coast Avifauna No. 7. Woods, R. S. 1930. Two more victims of the Cowbirds. Condor 32:126. ♦ LONG-BILLED MARSH WREN Cistothorus palustris TAXONOMY A. Type description AOU (1957), Telmatodytes palustris plesius: Cistothorus palustris plesius Oberholser, Auk, 14, no. 2, Apr. 1897, p^ 188. CFort Wmgate, N [ew] . M [exico] . ) . Telmatodytes palustris aestuarinus: T. p. aestuarinus Swarth, Auk, 34, no. T, July (June 30), T91/, p~] 310. (Grizzly Island, Solano County, California.) B. Current systematic treatments Paynter and Vaurie (1960), recognize four species in the genus Cistothorus; eleven subspecies of palustris. Passeri- f o rme s: Troglodyti dae . Ridgway (1904), discussion of morphological characteristics and geographic distribution in relation to systematic treatment. C. Synonomies of scientific nomenclature C. p_. plesius, Grinnell and Miller (1944): Troglodytes palustris; Telmatodytes palustris plesius, Cistothorus palustris paludicola, Telmatodytes palustris paludicola. C. p_. aestuarinus: Telmatodytes palustris paludicola; C. p_. paludicola. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), C. p_. plesius: Tule Wren, Western Marsh Wren. C. p_. aestuarinus: Tule Wren; Suisun Marsh Wren. Dawson (1923), C. £. aestuarinus: Swarth' s Marsh Wren, San Joaquin Marsh Wren. C. p. plesius: Interior Marsh Wren. II DESCRIPTION A. External morphology of adults Dawson (1923), C. p_. plesius: "Adult: Crown blackish; fore- head warm brown. . .color sometimes spreading superficially over entire crown; hind-neck and scapulars a lighter shade of brown; rump bright brown; a triangular patch on back blackish, with prominent white stripes and some admixture of brown, wings and tail fuscous or blackish on inner webs, brown with black bars on exposed surfaces; upper and under • • Cistothorus palustris (con't.) tail-coverts usually more or less distinctly barred with dusky; sides of head whitish before, plain brown or punctate behind; a white superciliary line; underparts white, tinged with ochraceous buff across breast, and with pale cinnamon- brown on sides, flanks, and crissum. Bill blackish brown above, paler brown below; feet and legs brownish." C. £. aestuarinus: "Like T. (C. ) p_. paludicola, but larger and somewhat darker; like T. I"C. ) £. plesius m size, but much darker . " C. £. paludicola; "Similar to T. (C. ) £. plesius, but smaller and with coloration decidedly barker." Ridgway (1904), detailed description of adults including plumage, soft parts, and measurements, as compared with T. £. palustris. B. External morphology of subadult age classes Ridgway (1904) concerning T. £. palustris: "Essentially like adults, but pattern of coloration less distinct, the pileum and hindneck uniform dull blackish, the back very indistinctly, if at all, streaked, and the whitish superciliary stripe less distinct (sometimes nearly obsolete)." C. Distinguishing characteristics Interspecific - Phillips (1975) "Short-billed Marsh Wren... has these upper tail coverts boldly barred and the crown streaked with whitish, not solidly dark." Peterson (1961), "known from other small wrens with white eye stripes by the white stripes on back." Intraspecific - Phillips (1975) "The migratory eastern races ...lack the faint dusky bars on the upper tail-coverts." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), Telmatodytes palustris: Central British Columbia, northern Alberta, south-central Saskatchewan, southern Manitoba, southern Ontario, southwestern Quebec, southern Maine, and eastern New Brunswick south to northern Baja California, south-central Mexico, the Gulf coast, and southern Florida. T. £. plesius: "Breeds from central British Columbia (Tachick Take, Springhouse, Lac la Hache, Okanagon Landing), central * • Cistothorus palustris (con't.) tand eastern Washington (Loomis, Kettle Falls, Spokane), Idaho (Lake Pend d Oreille) , western Montana (Forine, Swan Lake, Big Lake), northwestern Wyoming (Tower Falls), north- eastern Utah (Jensen), northwestern Colorado (Lag), south- eastern Wyoming (Laramie, Torrington, Cheyenne), and south- western Nebraska (Pine Bluffs, Crescent Lake Refuge) south to northeastern and central eastern California (Tule Lake, Pitt River, Rolands Marsh, Lake Tahoe), central Nevada (Yerington, Ruby Lake), south-central Utah (Margsvale), central New Mexico, and southwestern Texas (El Paso, Pena Creek)." T. £. aestuarinus: "Resident in Sacramento, San Joaquin, and Imperial valleys of California, and the Colorado River Valley from southern Nevada (Search light, St. Thomas) south to southern California (Sal ton Sea, Alamo Duck Preserve), northern Baja California (Cerro Prieto, mouth of the Hardy River), northwestern Sonora (Colorado River Delta), and south- western Arizona (Mittry Lake, California Swamp). B. California distribution of the species # Grinnell and Miller (1944), C. palustris plesius: "As breed- ing, northeastern plateau region, in Modoc, eastern Siskiyou and Lassen counties, and Tahoe area. C. p. aestuarinus: "Sacramento and San Joaquin valleys from at least Glenn and Butte counties south to Kern County, and Imperial Valley and valley of lower Colorado River, in Imperial County." C. California desert distribution Dawson (1923), C. p. plesius: "interior birds, breeding at high levels east or the Sierras, are obliged to retire in winter to. .. southeastern deserts, and the. . .overflowed margins of the Colorado River and 'New' River. . .Many spill over at this season into the San Diego district." Small (1974), "for breeding, coastally, length of state: also Central Valley, Imperial Valley and Modoc Plateau. D. Seasonal variation in distribution AOU (1957), T. p_. plesius: "Winters throughout breeding range and south to southern California (including Santa Cruz and San Nicolas Islands), southern Baja California (San Jose del Cabo), Michoacan, Mexico, central Veracruz, and southern Texas (San Antonio, Fort Brown, Corpus Christi)." • Cistothorus palustris (con't.) T. £. aestuarinus: "Found in winter in southern Utah." [ Dawson (192 J), C. p. aestuarinus: "Winters irregularly south to the San Diego district." Small (1974), "some withdrawal of birds from northeastern section during fall and winter." IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), C. p. plesius; "Typically, especially in nesting season, thick tracts of tall, straight- stemmed marshland vegetation as comprised of cattail, tule, and bulrush." C. p. aestuarinus: "Fresh- water or brackish marshland, typically as grown to beds of cattail, tule, or bulrush." Similar to C. p_. plesius. Small (1974), "fresh-water marshes, ponds, streams, and lakes grown with cattail, tule, bulrush." Miller (1951), Lower and Upper Sonoran and Transition Life Zones. B. Altitudinal range Grinnell and Miller (1944), C. p. plesius: "altitudes to 6200 feet." 4000 C. £. aestuarinus: "altitudes of known nesting stations, all below 500 feet." C. Home range size Verner (1965a) , C. p_. plesius: in Washington, 2500-9600 square feet. Welter (1935), "A single monogamous male occupied a territory of from 13,000 to 15,000 square feet... In the grass association this was extended to approximately 30,000 square feet." Kale (1965), comparison of mean territory sizes among study areas and in different years. D. Territory requirements Perch sites - Kale (1965) "down in the dense grass or near the tops of tall dead flower stalks remaining from the pre- vious year's crop of Spartina." Miller (1906), "cattail blade or a dead stalk. Courtship and mating sites - Verner (1965a), "After establish- ing a breeding territory the male begins building "courting" nests. . .grouped in a small area. . .Number of nests. . .ranges from one partial to four or five complete nests... As the season progresses more courting centers are built, often overlapping others. Most songs are delivered from the court- ing center and little foraging is done there." * Cistothorus palustris (con't.) Nest sites - Grinnell and Miller (1944) "Nests. . .above water, a greater measure of security against terrestrial marauders being thus probably secured. ' Verner (1965a) "usually placed in cattails (preferably in stands of moderate density), but occasionally. .. in bulrushes. A colony. . .placed their nests in the Spiraea, no cattails being available. Nest height... in direct relation to the height of supporting cover." E. Special habitat requirements Verner and Engelsen (1970), "cattail is the preferred nest- ing cover only if it has standing water. The importance of water could be in protection of the nest from predation and/or provision of a highly important food source. F. Seasonal changes in habitat requirements Grinnell and Miller (1944) C. p_. plesius: "In migrations and in winter any sort of low vegetation growing in water or on damp ground suffices for foraging and concealment. . . In its winter range, when its elevated and interior summer grounds are largely uninhabitable, this wren finds in southern California the wet season on, with. . .plenteous fresh water and the lush plant growths that are to its liking." Verner i and Engelsen (1970), "Bulrush typically grows in deeper water than cattail. .. Selection favored those males whose territories contained some bulrush because they were less likely to be forced to abandon their territories in mid- season." [See "Special habitat requirements"]] Swarth (1917) "Especially numerous winter visitant in the San Diegan district of southern California. In this region summer is the dry season, a period of such excessive aridity that birds with the needs... of the marsh wrens are closely limited as to habitat, being restricted to extremely cir- cumscribed areas about the few suitable permanent streams and sloughs. In winter this is all changed. Abundant rains often transform what were dry fields and pastures into ponds and marshes." V FOOD A. Food preferences Verner (1964) "an almost exclusively animal diet, especially aquatic forms and terrestrial forms with aquatic life stages." Welter (1935), "There is no actual selection of types of insects by the species but the food taken depends upon its predominance and accessibility. Beetles. . .aquatic larvae . . .Coleoptera and Diptera." Miller (1906), insects, their egg and larvae." Cistothorus palustris (con't.) B. Foraging areas Verner (1965b), "normally forage on or near the marsh floor." Verner (1964), "Much food for Seattle young was obtained from willow thickets. .. the importance of bulrushes for for- aging may result from their being more thoroughly broken down during the winter than is cattail, thus allowing more light to penetrate to the water surface and promoting higher production there... The greater proportion of foraging took place in it [bulrush]." Welter (1935) "Much of the food is obtained near or from the surface of the water. . .Upon the stems and leaves of the cattails and other plants." C. Foraging strategies Verner (1965b) "For an insectivorous species. .. food species would be less active, hence less conspicuous, at lower temper- atures. They would also be more easily seen in bright than in dull light... The most efficient period for a Marsh Wren to forage is probably during the afternoon, when ambient temperature reaches a maximum." Welter (1935), "The elong- ated bill and natural agility of the bird are important." D. Feeding phenology Verner (1965b) "Young birds were fed on larger and larger items as they grew older, whereas the adults continued to eat very small items, such as aphids and mites." Welter (1935), "By the time the birds arrive in the spring there is an abundance of insect food. . .As the season advances insect food becomes more plentiful." E. Energy requirements Verner (1965b), "If it takes adult wrens nearly half their available time just to meet their own energetic demands, they must be seriously pressed to feed four or five young as well... Must also store enough energy to pass the night ...Enough energy must be stored to meet unexpected exigencies during the night, such as sudden temperature drops or dis- turbance from a roost." VI REPRODUCTION A. Age at first breeding f e Cistothorus palustris (con't.) B. Territorial behavior Verner (1965a), C. p. plesius: "territorial limits were largely determined by the distribution of marsh vegetation, and birds utilized all of the areas they occupied." Welter (1936) "A male approaching too closely to the boundary of another's area is challenged by the song of the rightful owner. . .Several song perches are selected in different parts of the territory and the owner continues to go from one to another singing enroute." Kale (1965), "T. p_. griseus delimits his territory by singing at one end of it for several minutes and then moving to the other end and singing there." C. Courtship and mating behavior Verner (1965a), "After establishing a breeding territory the male begins building "courting' nests. . .Female approaches a male's territory, he immediately flies toward her, deliver- ing a rapid valley of songs with his tail cocked. . .Female examines and often enters one nest after another, being escorted to each by the male... Male practically ceases singing during courtship, resorting instead to display. . .After a female selects a mate, she either selects one of his courting nests for breeding and lines it... or she initiates a new nest, which is constructed chiefly by the male... A day or two before laying begins or shortly thereafter. .. shifts to another part of his territory. . .and starts building a new courting center from which he advertises for additional mates." Verner (1964) discussion of polygamy in different populations in Washington State. Welter (1936), description of courtship by male and a discussion of the song of the male. C. Nesting phenology -■ Verner (1965a), "high degree of synchrony in the initiation of nest construction by males. . .males build a number of nests that are never used for breeding purposes. . .breeding nests differ from non-breeding nests by having a substantial lining." Welter (1936) description and discussion of mul- tiple nests built by the male." E. Length of incubation period Verner (1965a), "Eggs. . .deposited at a rate of one per day... Incubation performed solely by the female." Mean incubation ranged from 14 to about 17 days near Seattle, Washington. Kale (1965) range of 12-14 days for 35 nests; mean of 13.1 days . Cistothorus palustris (con't.) F. Length of nestling period Verner (1965a), "undisturbed nest often contained young 15 or 16 days old. . .continued to feed fledglings for 12 or more days." Kale (1965) reports 12 or 13 day. "If left undisturbed the young may remain in the nest 13-15 days." G. Growth rates Welter (1935), "The average weight for the newly arrived wren is 0.87 of a gram but by the end of the twelfth day this has been increased to an average of 11.08 grams. During this time the gain is from 1 to 1.7 grams per day... During the period of greatest feather growth the gain in weight drops off markedly." Includes graph of weigth vs. age in days. H. Post-breeding behavior Verner (1965a), "As the young aged and became progressively more dependent the males' rates of singing and nest build- ing once again increased. Welter (1935), "The family group remains together for some time and it is not unusual in mid- September to see four, five, and six birds of an age still keeping together. The young do not remain in the territory of their parents but wander from place to place." VII POPULATION PARAMETERS A. Clutch size Verner (1965a), reports six as average; range of 4-8 eggs. B. Fledging success Kale (1965), "The number of eggs fledged in 1958 was 74 out of a total of 178 laid, or a nesting success of 42%>. In 1959, 86 eggs fledged out of 421 laid, or a nesting success of only 20%. In 1960. .. success of 7%. In 1961... 15%." C. Mortality rates per age class D. Longevity E. Seasonal abundance Grinnell and Miller (1944), C. p_. plesius: "summer resident in elevated northeastern corner of State; winter visitant (September to March) in southern half, chiefly; transient there and elsewhere." ' - Cistothorus palustris (con't.) • C. p_. aestuarinus : "Subject to fall and winter wandering of some individuals considerably out of breeding range." Welter (1935) "There is no marked exodus of birds from the marsh at a given time in the fall... As the time of departure approaches, there is an apparent flocking together of young birds, usually near the water's edge. . .Twenty- five or thirty birds may be observed together feeding near the surface of the water. The next day the numbers may be greatly reduced and in a short time only a few birds remain." Swarth (1917), "In winter. . .plesius is perhaps the most abundant of any form of the species, occurring in numbers over a large part of the state. . .May occasionally be found in winter at any point along the coast... both on the deserts and in the San Diegan region." F. Habitat density figures Welter (1935), "In an area 400 by 650 feet... eight males took up residence." Kale (1965), "The ecological density of 45-56 pr/ha (18-23 pr/acre) represents the number of birds in relation to the available wren habitat." Com- parison of different methods of calculating population densities. i'TII INTERSPECIFIC INTERACTIONS W A. Predation Bond (1939), six remains found in pellets of Barn and Horned Owls at Petroglyph Cliffs, California. Welter (1935), "The chief enemies. . .are some of the smaller mammals that reside in the marsh... No specific case has been observed but the appearance of the nest leads one to this conclusion ...Hawks and owls have a poor chance of adding this species to their diet as they are never very conspicuous and can easily hide in the dense vegetation." Kale (1965), reports Rice Rat, racoon, and mink prey on eggs and young (Georgia). Suspect Fish Crows and Boat-tailed Grackles. B. Competition Dawson (1923) "had constructed a sham nest hard against a completed structure of the Yellow-headed Blackbird, and to the evident retirement of its owner." Welter (1935) "it is apparently not unusual to find a colony of [bumble bees] in a nest of this species." Allen (1914), describes destruction of fifty-one nests of Red-winged Blackbirds. • 10 Cistothorus palustris (con't.) C. Parasitism Welter (1935), flea (Ceratophyllus garei) and louse (Philop- terusm. mirinotatus) recorded; hTppobascid flies observed. "The alimentary tracts of more than fifty birds were examined carefully without obtaining a single cestode or nematode." IX STATUS A. Past population trends Grinnell and Miller (1944), "Common to even abundant where conditions of habitat are most favorable." B. Present population status Small (1974), "common resident but some withdrawal of birds from northeastern section during fall and winter." C. Population limiting factors Kale (1965), "discussion of factors which may possibly limit the wren population (food, high tides, predation, terri- toriality and social behavior). D. Environmental quality: adverse impacts E. Potential for endangered status r r 11 Cistothorus palustris (con't.) kXI LITERATURE CITED Allen, A. A. 1914. The Red-winged Blackbird: A study in the ecology of a cat-tail marsh. Abst. Proc. Linn. Soc. N.Y. pp. 43-128. American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bond, R. M. 1934. Observations on raptorial birds in the Lava Beds - Tule Lake region of Northern California. Condor 41:54-61. Dawson, W. L. 1923. The birds of California. South Moulton Co. , San Francisco. Grinnell, J. and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. Kale, H. W. 1965. Ecology and bioenergetics of the Long- billed Marsh Wren in Georgia Salt marshes. Publ. Nut tall Ornithological Club No. 5. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. Vol. 50, No. 6. Miller, R. F. 1906. Long-billed Marsh Wren (Telmatodytes palustris) in Philadelphia County, Pennsylvania. Oologist 23:117-124. Peters, J. L. 1967. Checklist of birds of the world. Vol. 12. (D. Snow, ed.) Mus. Comp. Zool., Cambridge, Massachu- setts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. Phillips, A. R. 1975. Why neglect the difficult? Western Birds 6(3):69-86. Ridgway, R. 1904. The birds of North and Middle America. Part III. Bull. U.S. Nat. Mus. No. 50. Small, A. 1974. The birds of California. Macmillan Co., New York. Swarth, H. S. 1917. A revision of the marsh wrens of Calif- ornia. Auk 34:308-318. 12 Cistothorus palustris ( con ' t . ) Verner, J. 1964. Evolution of polygamy in the Long-billed Marsh Wren. Ecology 18:252-261. Verner, J. 1965a. Breeding biology of the Long-billed Marsh Wren. Condor 67:6-30. Verner, J. 1965b. Time budget of the male Long-billed Marsh Wren during the breeding season. Condor 67:125-139. Verner, J. and G. H. Engelsen. 1970. Territories, multiple nest building, and polygyny in the Long-billed Marsh Wren. Auk 87:557-567c Welter, W. A. 1935. The natural history of the Long-billed Marsh Wren. Wilson Bull. 42:3-34. ' < t • ♦ # LONG -EARED OWL Asio otus TAXONOMY A. Type description AOU (1957), Asio otus tuftsi Godfrey, Can. Field-Nat., 61, no. 6, Nov. -Dec. TW1 (Feb. 13, 1948), p. 196. (South Arm, Last Mountain Lake, Saskatchewan.) B. Current systematic treatments Peters (1940), recognizes six species in the genus Asio; three subspecies of the species otus. Order: Strigif ormes; Family: Strigidae. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Otus wilsonianus; Otus vulgaris wilsonianus; Otus brachyotus var. wilsonianus; Asio americanus ; Nyctalops wilsonianus; Asio wilsonius; Asio otus wilsonianus. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), American Long-eared Owl. DESCRIPTION A. External morphology of adults Ridgway (1914), detailed descriptions of adults and young, including plumage, soft parts, and measurements. Peterson (1961), A slender, medium-sized, grayish owl with long ear tufts... Face dark rusty." Dawson (1923), "Adult: Above finely mottled white and dusky, with apparently half -concealed ochraceous on subterminal margins of feathers, the design broadened on wings, --ochraceous, white, and dusky in patches; the wing-quills and tail distinctly barred--dusky with ochraceous basally, dusky with gray terminally; ear-tufts conspicuous, an inch or more in length, black centrally, with white and ochraceous edges; facial disc tawny; region about base of bill, or at least chin, white; blackish about eyes on inner sides, the edges, especially on forehead, finely mottled with black and white; tibiae, tarsi, and feet pale tawny, immaculate; remaining underparts white, ochraceous, and dusky, in bold, free pattern, and upper breast distinctly and heavily streaked, the sides and flanks distinctly barred, the belly exhibiting a combination of the two types; lining of wing pale tawny, unmarked basally, save for a dusky patch on tips of coverts, heavily barred distally. Bill and toe- nails blackish. The folded wings exceed the tail, and the bill is nearly concealed by black and white bristles." Asio otus (con't.) B. External morphology of subadult age classes * Ridgway (1914), detailed description of plumage and soft parts. Armstrong (1958), description of plumage changes as observed regularly to 59 days of age. Dawson (1923), "Everywhere, except on head and linings of wings, finely barred dusky and gray or ochraceous." C. Distinguishing characteristics Interspecific - Peterson (1961), "much smaller than Horned Owl, streaked lengthwise, rather than barred, beneath. 'Ears' closer together, toward center of forehead, giving a different aspect. .. Screech Owl is smaller, has shorter ears, lacks rusty face... In flight, Long-eared Owl's ear tufts are depressed; then grayer color, habitat distinguish it from Short-eared Owl." Intraspecific - III GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), "British Isles, western Europe from lat. 66°N. , Siberia from lat. 60°N. , and Japan south to the Azores, m Canary Islands, Morocco, Tunisia, southern Europe, Palestine, ^ Afghanistan, the Himalayas, Manchuria, Korea, and Formosa; southern Alaska, southern Mackenzie, southern Manitoba, central Ontario, southern Quebec, and Nova Scotia south to northwestern Baja California, southern Arizona, Oklahoma, Arkansas and Virginia." A. £. tuf tsi: "Breeds from southern Mackenzie (Fort Simpson, Fort Providence) , central British Columbia (Nulki Lake), and Saskatchewan south to southern California (including Catalina Island), northwestern Baja California (to lat. 30°N.), southern Arizona (Bates Well. Pima County, Santa Rita Mountains), New Mexico (Santa Fe), and western Texas." B. California distribution of the species Grinnell and Miller (1944), "Entire length of State east of northern humid coast belt; three centers of abundance, in northeastern Great Basin territory, in central valleys, and in San Diegan district. Peripheral stations: northern- most in coast belt, Bodega and Sebastopol, in Sonoma County . . .Northeasternmost, Goose Lake and Surprise Valley, Modoc County... to eastward on southern deserts, chiefly or perhaps entirely." Dawson (1923), "Locally resident, chiefly in interior valleys, on the oak-covered foothills, and along wooded streams of the Upper Sonoran zone, south (at least formerly) to San Diego. Sparingly resident on the Santa Barbara Islands... An occasional invader of the higher moun- tains." • Asio otus (con't.) C. California desert distribution Grinnell and Miller (1944), "in winter: Mohave River near Yermo, San Bernardino County. . .Palm Springs, Riverside County ...Palo Verde, Imperial County." Dawson (1923), "Numbers augmented in winter, at least in San Diego district and on the edges of the deserts." D. Seasonal variations in distribution AOU (1957), Asio otus in general: "In winter south to Egypt, Iraq, northwestern India, and southern China, and to Baja California, central Mexico, Texas, and Florida. Fossil, in the Pleistocene of California and Nuevo Leon." A. o. tuftsi: "Winters from southern Canada south to Northern Baja California, Sonora (Tiburon Island), and Durango." IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), "Typically, bottomlands grown to tall willows and cottonwoods; but also, west of Sierran divides, belts of live oaks, especially as paralleling stream courses." Armstrong (1958), "either coniferous or deciduous nesting habitats." Small (1974), "riparian woodlands and stands of live oaks along watercourses." Miller (1951), Lower and Upper Sonoran and Transition life zones." B. Altitudinal range Grinnell and Miller (1944), "ranges normally up to 2000 feet west of Sierras, up to 7000 feet east of Sierra Nevada; exceptionally has reached 9000 feet on San Jacinto Peak, Riverside County. . ..and 10,500 feet on White Mountains, Mono County." C. Home range size Craighead and Craighead (1956), during nesting season in Wyoming, 1947, reported ranges of three nesting pairs: 0.13 sq. mile (maximum diameter of 0.7 mile); 0.41 sq. mile (maximum diameter of 1.0 mile); 0.10 sq. mile (maximum diameter 0.5 mile). D. Territory requirements Perch sites - Marti (1976), "It does require small, dense trees for nesting and roosting." Randle and Austing (1952), "roosted at a height of six to twelve feet, close to the ♦ • Asio otus (con't.) trunk. In three places where the owls had a choice between trees taller than twenty feet and those smaller than fifteen / feet in contiguous groves they chose the smaller trees." Peterson (1961), "Usually seen 'frozen' close to trunk of dense tree." Courtship and mating sites - Nest sites - Armstrong (1958), "Nests in Michigan have been recorded from ground level to a height of 40 feet." Dawson (1923), "Usually a deserted nest of crow, magpie, heron, etc.; sometimes in rock-rifts or even on the ground... Nests regularly in live oaks and evergreens." E. Special habitat requirements Udvardy (1958), "The only bird that in North America is largely dependent on the deciduous woods is Asio otus." Grinnell and Miller (1944) "Open land productive of mice is requisite, as also presence of old nests of crows, hawks or magpies for breeding purposes." F. Seasonal changes in habitat requirements Wilson (1938), "During the late summer, fall and winter months they inhabited the coniferous woods and during their nesting and brooding seasons from March until June, they were found in the hard woods." (Michigan) * V FOOD A. Food preferences Errington (1932), "Total vertebrate kills from pellets and stomachs (quantitative data) amount to 3273: juvenile cotton- tail, 1; Norway rat, 3; meadow mouse, 2732: deer mouse, 497; shrew, 14; small bird (mostly finches), 26." Graber (1962), "The detailed record of pellet contents. .. indicates that Long-ears usually consume voles and deer mice entirely, while house mice are more often only partly eaten." (Illinois). Marti (1976), "feed upon small, nocturnal mammals that live in open lands, i.e., farmlands, grasslands, marshes and deserts." Includes detailed discussion of diet. B. Foraging areas Marti (1976), "This is a strictly nocturnal species. . .and apparently feeds almost exclusively in open lands." Getz (1961), Washtenow County, Michigan: "fed primarily on the meadow vole, and hunted in an old- field habitat. They apparently did not utilize a near-by marsh, although it Asio otus (con't.) t contained more voles than the old field. The use of the old field appears to be related to a lesser amount of cover in this habitat than in the marsh. Timbered areas nearer the roost than the old field and having a greater abundance of small mammals were not utilized. . .Therefore, apparently prefer open, grassy areas to timbered areas." C. Foraging strategies Marti (1976), "compared to many other North American owls this species has rather light wing-loading, which indicates efficiency of hunting on the wing." Dawson (1923), "strictly nocturnal in habit." D. Feeding phenology Errington (1932), reports the following from analysis of pellets and stomachs: Fall, winter, early spring, 1929-30, 99.66% mammals, 0.34% birds; Late spring, early summer, 1930, 87.62% mammals, 12.38% birds; Late summer, 1930, 92.6% mammals, 7.4% birds; Fall and early winter, 1930, 99.24% mammals, 0.76% birds; Late winter and early spring, 1931 , 100% mammals, (Wisconsin). Graber (1962), ''With the passing of winter into spring, there was a marked increase in frequency of house mice and least shrews in pellets at both roosts." E. Energy requirements Graber (1962), "Standard (basal) rate: 26 kcal . /bird/day (105 kcal. /ig. /day ) , aviary existence: 109 kcal . /bird/day (357 kcal ./kg. /day) , natural existence: 159 kcal . /bird/day (532 kcal. /kg. /day)." VI REPRODUCTION A. Age at first breeding B. Territorial behavior Bent (1938), "is normally so inactive and retiring during the daytime that we have learned very little about its behavior, except what we have seen of it when its nest or brood of young is disturbed." Dawson (1923), describes in- dividuals feigning prey capturing as a method of distracting attention from the nest. ♦ • Asio otus (con't.) C. Courtship and mating behavior Armstrong (1958), "The courtship pattern consisted of competitive calling, aerial performance, non-competitive calling, nest selection and copulation. . .Flights were sporadic and irregular and consisted of turning, twisting, diving, and wing slaps. An owl would suddenly disappear in a swoop or dive to the pines, and on several occasions, a cracking noise was heard, evidently made with the wings slapping each other." D. Nesting phenology Dawson (1923), "February -May; one brood." E. Length of incubation period Armstrong (1958), "lasted from 23 to 26 days... from 22 to 26 days." F. Length of nestling period Armstrong (1958), "When young were 25 or 26 days old, their wings were developed sufficiently to permit them to leave the nest." Whitman (1924), "The oldest left the nest when about four weeks old, but the younger ones... began crawling around in the branches long before they could fly." G. Growth rates H. Post-breeding behavior Wilson (1938), "offspring remained with the parents until January of the next mating season when all but the mated adults disappeared." VII POPULATION PARAMETERS A. Clutch size Whitman (1924), reports a nest containing four eggs and two newly hatched young. Dawson (1923), "3 to 6; subsperical, white (or not infrequently red-spotted with nest-marks). B. Fledging success Craighead and Craighead (1956), report in Wyoming, 1947: 93% nesting success based upon number of fledglings (8) per total eggs laid. ' Asio otus (con't.) . C. Mortality rates per age class Craighead and Craighead (1956), report for Wyoming, 1947: 7% of the clutches were incomplete or nests failed to re- ceive eggs; 77o of the eggs were destroyed, infertile, or failed to hatch; no mortality in the nest after hatching was observed. D. Longevity E. Seasonal abundance F. Habitat density figures Randle and Austing (1952), "Where more than one bird was found in the same group of trees, roosting was communal. In one place twenty- seven birds flushed from a clump of four fifteen-foot pines. In a second place five birds were in a twelve- foot pine and sixein two neighboring trees. On another occasion eight were discovered in two intermingling trees." rill INTERSPECIFIC INTERACTIONS A. Predation m Marti (1976), detailed analysis of prey items of this species. Armstrong (1958), examination of predation on mouse popula- tion near nesting sites of this species in Michigan. Sutton (1926), reports this species preying upon Ruffed Grouse in Cameron County, Pennsylvania. "It seems hardly possible that so light a creature as the Long- eared Owl should cus- tomarily kill creatures so much heavier than itself." B. Competition Wilson (1938), "Occupied and hunted the same areas used by Marsh Hawks (Circus hudsonius), and the Red- shouldered Hawk Buteo lineatus)." (Michigan) C. Parasitism IX STATUS A. Past population trends Grinnell and Miller (1944), "Resident within State, but with markedly irregular wanderings of individuals and groups. In general, numbers are so large as to warrant term common,' even 'abundant' locally. Reduction of late years is apparent, in the main probably as result of clearing of bottomlands for farming . " • Asio otus (con't.) B. Present population status Small (1974), "resident but populations shift about in unknown pattern." C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status • Asio otus (con't.) kXI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Armstrong, W. H. 1958. Nesting and food habits of the Long- eared Owl. Michigan State University Publications of the Museum, Biological Series, Vol. 1, No. 2. Bent, A. C. 1938. Life histories of North American birds of prey. Part 2. U.S. Nat. Mus. Bull. No. 170. Craighead, F. C, Jr. and J. J. Craighead. 1956. Hawks, owls and wildlife. Stackpole Co., Pennsylvania. Dawson, W. L. 1923. The birds of California. South Moulton Co., San Francisco. Errington, P. L. 1932. Food habits of southern Wisconsin raptors. Condor 34:1-186. Getz, L. L. 1961. Hunting areas of the Long- eared Owl. Wilson Bull. 73:79-82. Graber, R. R. 1962. Food and oxygen consumption in three species of owls (Strigidae). Condor 64:473-487. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. Marti, C. D. 1976. A review of prey selection by Long-eared Owl. Condor 78:331-336. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. Vol. 50. Peters, J. L. 1940. Checklist of birds of the world Vol. IV. Mus. Comp. Zool. , Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. Randle, W. and R. Austing. 1952. Ecological notes on Long- eared and Saw-whet Owls in southwestern Ohio. Ecology 33: 422-426. Ridgway, R. 1914. The birds of North and Middle America. Part 6. U.S. Nat. Mus. Bull. No. 50. Small, A. 1974. The birds of California. Macmillan Co., New York. 10 Asio otus (con't.) Sutton, G. M. 1926. Long-eared Owl capturing Ruffed Grouse. Auk 43:236-237. Udvardy, M. D. F. 1958. Ecological and distributional analysis of North American birds. Condor 60:50-66. Whitman, F. N. 1924. Nesting habits of the Long-eared Owl. Auk 41:479-480. Wilson, K. A. 1938. Owl studies at Ann Arbor, Michigan. Auk 55:187-197. i • MOUNTAIN BLUEBIRD Sialia currucoides I TAXONOMY A. Type description Sialia currucoides - AOU (1957) Motacilla s. Sylvia Curru- coides "Borkh," Bechstein, in Latham, Allgem. Ueb. Vogel, vol. 3, pt. 2, 1798, p. 546, pi. 121. (Virginien = western America.) . B. Current systematic treatments AOU (1957) considers this species a member of the avian Order Passeriformes, Family Turdidae (Thrushes, Solitaires, and Bluebirds) ; listed as monotypic. Peters (1964) lists the Mountain Bluebird as a member of the Subfamily Turdinae, Family Musicapidae; also considered monotypic C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Sialia arctica. Ridgway (1907) adds, Erythaca arctica; Sylvia arctica; Sialia macroptera. r D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Arctic Bluebird; Rocky Mountain Bluebird. II DESCRIPTION A. External morphology of adults Ridgway (1907) gives detailed description of plumages and measurements of all age classes and sexes. Describes adult male as "above plain rich turquoise. . .bill, legs, and feet, black; iris, dark brown." Miller and Stebbins (1964), "A bluebird without any rich brown areas... Male light azure blue above and below, except belly, which is white. B. External morphology of subadult age classes Ridgway (1907) details subadult plumages — "Young male... light brownish gray or drab-gray. .. indistinctly streaked with white. Young female, similar to the young male, but blue of wings and tail much duller." Wheelock (1920), "Young: Grayish, indistinctly streaked or mottled with white; wings and tail blue." # Sialia cur rue o ides ( con f t . ) C. Distinguishing characteristics Interspecific - Peterson (1961), "Similar species: (l) Other bluebirds have red breasts. (2) Male Blue Crosbeak has a thick bill, brown wing bars. (3) Male Indigo Bunting is smaller, very much darker." Intraspecific - Ridgway (1907) states that the female is "plain mouse gray or smoky gray, sometimes faintly tinged with greenish blue. .. turquoise or light cerulean blue." Adult male-- length 169 mm; wing 117 mm; tail 72 mm, and female-- length 166 mm; wing 112 mm; tail 68 mm. Miller and Stebbins (1964), "Male light azure blue. . .Female dull brownish with pale, dull blue rump, tail, and wings." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) gives the range of the Mountain Bluebird (Sialia currucoidesj as "Breeds from central Alaska, southern Yukon, southern Mackenzie, southern Saskatchewan, and southwestern Manitoba south along eastern slopes of the coast ranges, and in the Sierra Nevada and the Rocky Mountains to north- western and central southern California (South Yolla Bolly Mountains. Mt. Sanhedrin, Panamint Mountains, San Bernardino Mountains) central and southeastern Nevada, northern Arizona, southern New Mexico, western Oklahoma, Colorado, western Nebraska, South Dakota, and northeastern North Dakota. Winters from southern British Columbia and western Montana south to northern Baja California, Sonora, southern Chihuahua, Guanajuato, central Nuevo Leon, and southern Texas; extending to the Pacific coast and offshore islands, and to western Kansas, western Oklahoma, and western Texas." Peters (1964), "Breeds from central Alaska, southern Yukon, southern Mackenzie, and southwest Manitoba south in the mountains to southern California, northern Arizona, southern New Mexico, and in plains of Dakotas; winters from southern British Columbia south to Baja California, Sinaloa, Michoacan, Guanajuato, Nuevo Leon, and southern Texas." B. California distribution of the species Grinnell and Miller (1944) list range as "Breeds along Cascade — Sierra Nevada Mountain system and on high plateaus and mountains to eastward from Warner Mountains south to Panamint Mountains, Inyo Co. ; also in inner northern coast ranges from Siskiyou Co. south to Mt. Sanhedrin, Mendocino Co. , and in San Bernardino Mountains of southern California. In winter, throughout state at lower levels." Small (1974) gives range as "for breeding, Sierra Nevada and Cascades, K ♦ Sialia currucoides (con't.) Warner Mountains, inner Coast Range south to Mendocino County, San Bernardino Mountains; in winter sometimes com- mon in San Joaquin Valley, Carrizo Plain in eastern San Luis Obispo County, Antelope Valley, and Imperial Valley." Wheelock (1920), On the higher Sierra Nevada, from Mt. Shasta to the San Bernardino Mountains." C. California desert distribution Grinnell and Miller (1944) summarize winter desert records, including — Death Valley, Twentynine Palms, Needles, and Brawl ey. At Joshua Tree National Monument, Miller and Stebbins (1964) called this species a "Winter visitant in moderate numbers. Recorded from: Upper Covington Flat, March 10; Quail Spring, January 27; Twentynine Palms, Nov- ember 16... March 24." Willett (1951) stated that although they do not remain to breed, these bluebirds are found on southern California deserts during winter. Wauer (1964) found Mountain Bluebirds breeding in the limber pine asso- ciation between 8,000 and 9,000 feet in the Panamint Moun- tains, Death Valley. Gilman (1935) noted the presence of this bluebird in Death Valley (Furnace Creek Ranch; Eagle Borax Works) from January to mid- April. Carter (1937) noted Mountain Bluebirds, often in mixed flocks of Western Bluebirds, at Twentynine Palms between January and mid- March. Van Rossem (1911) noted this species near the Sal ton Sea during winter. Lamb (1912) discovered only four Moun- tain Bluebirds between December and March on the Mohave Desert near Daggett (San Bernardino Co.). During winter in the lower Colorado Valley, Price (1899) found these bluebirds to be "Common about alfalfa fields in the river bottom." Grinnell (1904) noted this species wintering near Palm Springs, Riverside Co. Near Victorville during winter, Mailliard and Grinnell (1905) encountered several flocks of these bluebirds "out on the desert quite a distance from the (Mojave) river." D. Seasonal variations in distribution Grinnell and Miller (1944) found in California that "Winter occurrence in lowlands irregular as to date and variable from year to year; noted chiefly from November to March." Small (1974) gives seasonal status in California as "summer visitor in mountains and northeastern plateau; winter visitor in some lowland areas." In California, Willett (1933) noted "Breeds in higher mountains, mostly on eastern slope, south to San Bernardino Range; more or less common in lower country in winter." Sialia currucoides (con't.) IV HABITAT I A. Biotopic affinities In California, Grinnell and Miller (1944) give habitat as "Widely open terrain, the ground covered with short grass, alpine turf, stunted or widespread bushes, or even rock shingle. At Joshua Tree during winter, Miller and Stebbins (1964) noted Mountain Bluebirds on "open desert." B. Altitudinal range In California, altitudes of known nesting range from 4,000 to 12,000 feet (Grinnell and Miller 1944J. C. Home range size In Montana, Power (1966) found "The smallest territory... was only approximately 100 yards wide, while other terri- tories had no clear boundries, and the resident bluebirds occasionally flew. ..from their nests, up to about one- quarter mile away." D. Territory requirements Perch sites - "Perches may be provided by rocks, bush tops, or scattered trees or small or moderate stature" (Grinnell f and Miller 1944). Haecker (1948) noted these bluebirds feeding from a wire, usually 8 to 15 feet above ground. Courtship and mating sites - Power (1966), "The male chased his mate and nearly caught her in flight. . .both perched next to one another on a wire fence. . .while on an elevated perch, males simply flew up to their mates and mounted them." Nest sites - Grinnell and Miller (1944), "For nest sites dead trees usually are present, but rock crevices and man- made structures may be used." Peterson (1961), "In hole in tree, stub, cliff, bird box." Wheelock (1920), "In old woodpecker holes or in natural cavities of dead trees." In Wyoming, Calder (1970) noted a Mountain Bluebird pair nesting in an old Dipper (Cinclus mexicanus) that was placed under a bridge. E. Special habitat requirements On the California desert (Joshua Tree), Miller and Stebbins (1964) noted that this species "frequents the desert only in the coldest months." * Sialia cur ruco ides (con't.) F. Seasonal changes in habitat requirements Small (1974), "for breeding, subalpine forest of Canadian and Hudsonian life zones... in winter not uncommon in certain open plains and grasslands and more arid agricultural lands." Peterson (1961), "Open terrain with scattered trees; in winter, also treeless terrain." V FOOD A. Food preference Martin et al. (1961) describe animal food as--beetles, particularly ground beetles, and weevils are the major items in the diet, followed by grasshoppers and crickets, ants, caterpillars, and bugs. Plant food includes grapes and elderberries. In California, Wheelock (1920) noted "Crick- ets, grasshoppers, beetles, butterflies, and worms are their menu, with a few berries." B. Foraging areas "The insects for which these bluebirds forage may be taken either on the ground or in the air" (Grinnell and Miller 1944). Grinnell and Storer (1924) noted this species for- aging on grasslands and meadows in Yosemite. In Arizona, Phillips et al. (1964) found this bluebird foraging in open country, farmlands, grasslands, and open berry-bearing woods and brush. C. Foraging strategies Grinnell and Miller (1944), "Open tracts of ground and snow banks are searched over from the wing by cruising out from distant resting places. High tolerance of wind and light exposure is shown." Miller and Stebbins (1964) found that on California deserts (winter), this bluebird's insect food is taken chiefly from the open ground. Wheelock (1920) "they have all the habits of flycatchers. .. flying out after insects, or skimming the air like swallows, and hovering like hummingbirds." Power (1966), "Mountain Bluebirds have three distinct types of foraging behavior, used in the following order of frequency: Perch- feeding, hovering, and f lycatching." D. Feeding phenology Martin et al. (1961) notes the taking of grapes and elder- berries by bluebirds, especially during summer, fall and winter. Sialia cur ruco ides (con't.) E. Energy requirements While wintering on California deserts, Miller and Stebbins (1964) felt that the insect food of these bluebirds pro- vided adequate moisture. VI REPRODUCTION A. Age at first breeding Power (1966) reported that a young banded in 1962 returned to nest in 1963 in a Montana study (no sex given) . B. Territorial behavior Power (1966) described this species territory as "a large breeding area wherein courtship, copulation, nesting, and food- seeking occur. . .Nesting territories were defended by both sexes.' Details of the mechanisms of territorial defense, including advertising song and fighting behavior, are duscussed. C. Courtship and mating behavior Power (1966) noted that "Pair formation occurred quickly, after females arrived and joined territorial males. . .Early coition attempts by males were repulsed. In precopulatory displays, females on an elevated perch held their bodies horizontal with heads raised, wings slightly lowered, and tails raised." D. Nesting phenology In California, Wheelock (1920) reported the breeding season as May to July. Power (1966) found that 50% of all pairs that successfully raised first broods attempted second broods (Montana). In southwestern California, this species nests "mostly in May" (Willett 1933). Bent (1964) gives California egg dates as "34 records, April 5 to July 17; 17 records, June 9 to June 18, indicating the height of the season." E. Length of incubation period Wheelock (1920) reported a 14 day period. In Montana, Power (1966) listed incubation as lasting 13 days. Haecker (1948) gave a 13 or 14 day period (Wyoming). Sialia cu r rue o ides ( con ' t . ) F. Length of nestling period ™ Power (1966) found that "Young normally fledged between 22 and 23 days of age. . .Fledglings began feeding themselves at about 33-34 days of age. . .Fledglings became completely food independent at 22-28 days after leaving the nest (44-51 days of age)." G. Growth rates Wheelock (1920) found that "On the second day down begins to appear.. on the fourth or fifth day the eyes show signs of opening; on the sixth day they open, and the down is well spread... The young bluebirds double their weight every 24 hours for the first weeks." H. Post-breeding behavior Small (1974) states that after breeding, these bluebirds frequently range upwards into Arctic Alpine Life Zone in California. Grinnell and Storer (1924) noted the formation of "small scattering companies" during fall and winter in California mountains. Power (1966) noted that "By late August flocks were composed of birds "of all ages and sexes." II POPULATION PARAMETERS A. Clutch size Peterson (1961), "Eggs (4-6; 8) pale blue." Bent (1964) gives a range of 4 to 8 eggs per clutch, with sets of 5 and 6 the commonest. B. Fledging success Power (1966) found hatching success was 76.67o, and nest success (those fledging at least one young) was 68.7% in a Montana study. C. Mortality rates per age class D. Longevity E. Seasonal abundance Wauer (1962) noted that in Death Valley, wintering Mountain Bluebirds are "sporadic in occurrence; they are common some winters and absent others." Sialia currucoides ( con ' t . ) F. Habitat density figures In a Sierra Nevada conifer forest, Bock and Lynch (1970) found 15.2 breeding pairs per 100 acres of Mountain Blue- birds. In Wyoming, Finzel (1964) noted 6-7 bluebirds per 40 acres. In a Wyoming aspen forest, Salt (1957) found about 30 Mountain Bluebirds per 100 acres during summer. Ill INTERSPECIFIC INTERACTIONS A. Predation Marti and Braun (1975) found that Mountain Bluebirds made up 5.6% of a nesting Prairie Falcons diet on the tundra of Colorado (above 11,000 feet). In north-central Colorado, Marti (1974) noted this bluebird was taken only once in over 4,000 kills by a Barn Owl. Power (1966) noted that "The only probable predators observed were a Marsh Hawk, a Sparrow Hawk, and a group of Common Crows" (Montana) . In British Columbia, Munro (1940) found Sharp-skinned Hawks taking this bluebird for food. B. Competition Power (1966), in a Montana study, found "nest-site competitors were Tree Swallows, House Wrens, Mountain Chickadees, Red- shafted Flickers, and two rodents." Munro (1943) noted the unsuccessful attempt by a pair of Mountain Bluebirds to take a nest hole from Hairy Woodpeckers. C. Parasitism Friedmann (1963) and Friedmann et al. (1977) noted that cowbird parasitism of Mountain Bluebirds is extremely rare. IX STATUS A. Past population trends Grinnell and Miller (1944), "Common summer resident in the mountains; but rated as very common or abundant in north- east section." B. Present population status Johnson (1974) reported an apparent increase in the Dreed- ing population of this bluebird since a 1940 study in the Grapevine Mountains, Death Valley National Monument, Nevada. Arbib (1976) concluded that the Mountain Bluebird is de- creasing in the mountain regions of the western United States. ' 1 Sialia currucoides (con't.) C. Population limiting factors In Montana, Power (1966) concluded that "highly special- ized nesting requirements have produced a relatively un- adaptable species, whose population has declined as a result of environmental changes of recent decades." Haecker (1948) felt that lack of nesting cavities was the main deterrent to range expansion of this species. In northern California, Grinnell et al. (1930) noted that the presence of this species was largely determined by the availability of suit- able nest holes. D. Environmental quality: adverse impacts E. Potential for endangered status 10 Sialia currucoides ( con ' t . ) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore MD. 691 pp. Arbib, R. 1976. The blue list for 1977. Am. Birds 30:1031- 1039. Bent, A. C. 1964. Life histories of North American thrushes, kinglets, and their allies. U.S. Nat. Mus. Bull. 196. Bock, C. E. and J. F. Lynch. 1970. Breeding bird populations of burned and unburned conifer forest in the Sierra Nevada. Condor 72:182-189. Calder, W. M. 1970. Use of Dipper nest by Mountain Bluebird, Condor 72:498. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39: 210-219. Finzel, J. E. 1964. Avian populations of four herbaceous communities in southeastern Wyoming. Condor 66:496-510. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233. 276 pp. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the para- sitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Gilman, M. F. 1935. Notes on birds in Death Valley. Condor 37:238-242. Grinnell, J. 1904. Midwinter birds at Palm Springs, California. Condor 6:40-45. Grinnell, J., J. Dixon and J. M. Linsdale. 1930. Vertebrate natural history of a section of northern California through the Lassen Peak region. Univ. California Publ. Zool. 35: 1-594. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp. Grinnell, J. and T. I. Storer. 1924. Animal life in the Yosemite. Univ. California Press, Berkeley. 752 pp. Haecker, F. W. 1948. A nesting study of the Mountain Bluebird in Wyoming. Condor 50:216-219. » 11 Sialia currucoides (con't.) Johnson, N. K. 1974. Montane avifaunas of southern Nevada: Historical change in species composition. Condor 76:334- 337. Lamb, C. 1912. Birds of a Mohave Desert oasis. Condor 14: 32-40. Lane, J. 1968. A hybrid Eastern Bluebird X Mountain Bluebird. Auk 85:684. Mailliard, J. and J. Grinnell. 1905. Midwinter birds on the Mojave Desert. Condor 7:71-77; 101-102. Mansfield, G. S. 1946. Wintering Mountain Bluebirds on the Santa Barbara coast. Condor 48:285. Marti, C. D. 1974. Feeding ecology of four sympatric owls. Condor 76:45-61. Marti, C. D. and C. E. Braun. 1975. Use of tundra habitats by Prairie Falcons in Colorado. Condor 77:213-214. Martin, A. C, H. S. Zim and A. L. Nelson. 1961. American wildlife and plants. McGraw-Hill Book Co., New York. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Munrb, J. A. 1940. Food of the Sharp- skinned Hawk. Condor 42:168-169. Munro, J. A. 1943. Competition between Mountain Bluebirds and Hairy Woodpeckers. Condor 45:74. Murie, 0. J. 1934. Unusual Mountain Bluebird nests. Condor 36:164-165. Peters, J. L. 1964. Checklist of birds of the world. Vol. 10 (E. Mayr and R. A. Paynter, Jr., eds.). Mus. Comp. Zool., Cambridge, Mass. 502 pp. Peterson, R. T. 1961. A field guide to western birds. Houghton Mifflin Co., Boston. 309 pp. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. 212 pp. Power, H. W. 1966. Biology of the Mountain Bluebird in Montana. Condor 68:351-371. Power, H. W. 1974. The Mountain Bluebird: sex and the evolu- tion of foraging behavior. Ph.D. thesis, Univ. Michigan, Ann Arbor. « 12 Sialia currucoides ( con ' t . ) Price, W. W. 1899. Some winter birds of the lower Colorado Valley. Condor 1:89-93. Ridgway, R. 1907. The birds of North and Middle America. Part 4. Bull. U.S. Nat. Mus. No. 50. Salt, G. W. 1957. An analysis of avifaunas in the Teton Mountains and Jackson Hole, Wyoming. Condor 59:373-393. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Stoner, E. A. 1939. Mountain Bluebirds hovering. Condor 41:172. Van Rossem, A. 1911. Winter birds of the Salton Sea region. Condor 13:129-137. Wauer, R. H. 1962. A survey of the birds of Death Valley. Condor 64:220-233. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Weydemeyer, W. 1934. The song of the Mountain Bluebird. Condor 36:164. Wheelock, I. G. 1920. Birds of California. Fifth Edition. ^fc A. C. McClurg & Co., Chicago. 478 pp. ^^ Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. J MOUNTAIN CHICKADEE ■ Parus gambeli I TAXONOMY A. Type description AOU (1957) Parus gambeli baileyae Grinnell, Condor, 10 no. 1, Feb. 1, 1908, p. 29. (Mount Wilson, 5500 feet alti- tude, Sierra San Gabriel, Los Angeles County, California.) Penthestes gambeli inyoensis Grinnell, Univ. California Publ. Zool. , 17, no. 17, May 4, 1918, p. 509. (Panamint Mountains (northern part), 3 miles east of Jackass Spring, 6200 feet altitude, Inyo County, California.) B. Current systematic treatments Behle (1956), recognizes seven subspecies of Parus gambeli (gambeli , grinnelli , abbreviatus , baileyae, atratus , inyoensis , wasatchensis ) . Detailed discussion of racial characters and comparisons; geographic distribution; local- ities, and geographic variation and intergradation. Snow (1967) recognizes 43 species in the genus Parus ; five subspecies of gambeli. Passeriformes : Paridae. W Ridgway (1904) discussion of morphological characteristics and geographic distribution in relation to systematic treat- ment. * C. Synonomies of scientific nomenclature Grinnell and Miller (1944), P. g_. inyoensis : Penthestes gambeli ; Penthestes gambeli baileyae ; P. g_. baileyae : Parus montanus ; Penthestes gambeli baileyae ; Penthestes gambeli gambeli. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), P. g. inyoensis : Inyo Mountain Chickadee; Bailey Mountain Chickadee. P. g_. baileyae : Rocky Mountain Chickadee; Mountain Titmouse; Bailey Chickadee; Bailey Mountain Chickadee. II DESCRIPTION A. External morphology of adults Ridgway (1904), detailed description of plumage, soft parts, with measurements, adults spring and summer versus autumn and winter. Udvardy (1977), "White eye-stripe, black cap and bib ; pale gray flanks . " » Par us gambeli (con't.) B. External morphology of subadult age classes Ridgway (1904), "Young. --Similar to adults but the back of the head and neck duller, white superciliary streak much less distinct (pale gray rather than white) and edgings of greater wing-coverts and tertials faintly tinged with pale brownish buff." C. Distinguishing characteristics Interspecific - Peterson (1961), "Similar to Black-capped Chickadee, but black of cap interrupted by white line over each eye. Sides lack buff." Intraspecific - Behle (1956), "The race inyoensis can be distinguished from baileyae by its much paler, Euffy, less plumbeous appearance, narrower bill, and longer tail." LI GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), "Resident in the Rocky Mountains, the Sierra Nevada, and the inner coast ranges from northwestern British Columbia and southwestern Alberta to northern Baja California, central and southeastern Arizona, central and southeastern New Mexcio, and southwestern Texas. B. California distribution of the species AOU (1957), Parus gambeli baileyae: "Resident in the moun- tains of southern California (San Lucia Mountains, Mount Pinos, and the San Bernardino, San Jacinto, and Laguna Mountains)." Parus gambeli inyoensis: "Resident in the Great Basin from southcentral Idaho. . . through central and eastern Nevada. . . and western and central southern Utah. .. south to eastern California (White, Inyo, and Panamint Mountains, Clark Mountains), and southern Nevada." Grinnell and Miller (1944), P. £. inyoensis : "Higher mountain masses lying east and soutHeast of Sierra Nevada. . . southern Great Basin ranges ...from vicinity of Mono Craters and eastward to include White Mountains, in Mono County, south along Inyo Mountains to and including Grapevine, Panamint, and Argus mountains, in Inyo County, and Clark Mountain, eastern San Bernardino County." P. g. baileyae: "Higher Mountains of southern California. . . southeast from high parts of Santa Lucia Mountains, Monterey County, interruptedly, to Tejon Mountains, Kern County, and through mountainous parts of intervening counties as far as Cuyamaca and Laguna mountains, in San Diego County." 4 m m Par us gambeli (con't.) C. California desert distribution Dawson (1923) P. g. baileyae: Mt. Wilson, Los Angeles County; San Bernardino Mountains. P. £. inyoensis : "from the vicinity of Mono Craters in the White Mountains, in Mono County, south to the Panamint Mountains, in Inyo County." Behle (1956) P. g. baileyae: "In winter chickadees of this race are known to occur m the lower valleys at the bases of the mountains , having been recorded from Pasadena and in the desert along the Mohave River at Victorville. " Jaeger (1947), observation of individual foraging creosote bush in Lucerne. Miller (1951) P. g. inyoensis: Inyo Moun- tains. P. £. baileyae: San Bernardino, San Jacinto, San Diegan Mountains. D. Seasonal variations in distribution Small (1974), "small numbers descend to lowlands during fall and winter." Dixon and Gilbert (1964), "adult(s)... are sedentary on their breeding grounds, and that in winter months they form stable social groups in which the sexes are approximately equal. . .Alt itudinal movements are performed largely if not solely by first-year birds. Udvardy (1977), "frequently descends to the lowlands in winter. In November an occasional flock can be found near sea level in desert oases containing conifers such as Palm Springs, California, while other flocks, will still be at '8500 feet in the subalpine forest of adjacent Mount San Jacinto." IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), P. g. inyoensis: "Coniferous trees, from pinons, even where fairly open, up to stunted limber pines at timber line (on White Mountains); also tracts of mountain mahogany." P. _g. baileyae: "Coniferous trees, especially as growing in open stands. These may be mixed with such deciduous trees as black oak; used also for foraging and even nesting, but coniferous trees must also be within daily cruising radius." Small (1974), "montane forest and lower portions of the subalpine forest in the Transition and Canadian Life Zones." Miller (1951), Transition, Canadian, and Hudsonian Life Zones. Dixon (1961), discussion of distribution and niche relationships of Parus. ♦ # Parus gambeli (con't. ) B. Altitudinal range Gnnnell anc Miller (1944), P. g_. inyoensis : "6500 feet up ^T to 11,500 feet on White Mountains. Descends to at least 5 60 0 feet in autumn as near Benton, Mono County." P. g. baileyae : "of known nesting, 3000 feet in Santa Lucia Mountains up to 10,600 feet on San Bernardino Peak, San Bernardino County." C. Home range size Laudenslayer and Balda (1976), mean territory size of 1.5 ha. D. Territory requirements Perch sites - Courtship and mating sites - Dixon, Stefanki and Folks (19 70) "terminal solicitation and coition occurred in leaf- less aspens interspersed among the conifers." Nest sites - Barlow (1901) "Rotten stubs ... particularly where the core of the tree has rotted away, leaving a cavity . . .A majority were in pine or spruce stubs with the entrance at the top." Also, deserted woodpecker holes. • E. Special habitat requirements Grinnell and Miller (1944), "coniferous trees must also be within daily cruising radius. For nesting, the pines or other trees must be, at least in part, dead or decaying... must afford suitable-sized cavities, woodpecker-excavated or natural. .. low rotting stumps often suffice." F. Seasonal changes in habitat requirements V FOOD A. Food preferences Dawson (192 3) "moths' eggs, spiders, wood-boring grubs." B. Foraging areas Bock (1969) "predominantly in ponderosa pine ... largely on the needles and smaller twigs." Bent (1946) reports that nothing specific has been published on the food of any of the races of the Mountain Chickadee. "But its feeding habits are similar to those of other chickadees; it has- repeatedly been observed examining the twigs, foliage, and crevices in the bark of trees, where it doubtless finds a variety of insect food. Laudenslayer and Balda (1976) "foraged in .. Parus gambeli (con't.) pinyon pines 45.5% of the time compared to 9.0% usage of the ponderosa pine ... latter figure is surprisingly low for species A that normally reach their highest densities in the ponderosa W pine forest." (Arizona). C. Foraging strategies Laudenslayer and Balda (19 76) "used the hanging posture in addition to standing." D. Feeding phenology Dixon (1965) "are exceedingly active birds and seldom remain in one site for more than a few minutes, even though food may be abundant there..." E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior C. Courtship and mating behavior Dixon, Stefanski, and Folks (1970), discussion of precopula- fc tory behavior, including spectrographs of vocalizations. J Courtship feeding was not observed." The male solicitation calls... may be adaptive in attracting the attention of the mate in dense foliage of conifers." D. Nesting phenology Barlow (1901) "begins nest-building early, being but little influenced by the elements." Weydemeyer (197 5) reports earliest date for young in nest as 2 8 May (19 38); young left nest, 17 June (19 7 3) in Lincoln County, Montana. E. Length of incubation period Bent (19 46) reports no information on the period of incu- bation F. Length of nestling period G. Growth rates H. Post-breeding behavior # Minock (19 71) , examination of dominance hierarchy in winter- ing flocks. Found that at intraflock level site-related dominance does not seem to be operating although it is important between flocks . Par us gambeli (con't.) II POPULATION PARAMETERS A. Clutch size Dawson (1923), "four white eggs." Barlow (1901), reports from seven to nine young in nests, eight eggs in another. B. Fledging success C. Mortality rates per age class D. Longevity Dixon (1975), reports 10 year old male feeding nestling (identified by bands), Cache County, Utah. Two additional males of ages 7 years, 11 months; 7 years, 9 months. One female recorded at age 5 years, 7 months. E. Seasonal abundance Winternitz (1976), "The most numerous species [Crow Gulch, Pikes Peak, ColoradoJ were the Mountain Chickadee and... Junco caniceps. These two represented less than 10% of the species present in any one year but contributed about 25% of the breeding pairs." F. Habitat density figures Miller (1940), reports three pairs upon 40 acres of Transi- tion Zone timber. Franzreb (1975) reported 71.5 breeding pairs per 100 hectares, Thomas Creek, White Mountains, Arizona, summer 1973. Franzreb (1976), discussion of method of pre- dicting avian densities. Calculates 105.6 breeding birds per 100 hectare and 111.8 breeding birds per hectare using two different methods (study site in White Mountains, Arizona). II INTERSPECIFIC INTERACTIONS A. Predation B. Competition Minock (1972), detailed description of observations of dominance interactions between Black-capped and Mountain Chickadees at winter feeding stations. "Black-capped Chickadees usually were dominant over Mountain Chickadees. However, since Mountain Chickadees won a substantial number of contests, an analysis of several factors bearing on the outcome of encounters is made. The ones having the greatest effect are sex of the participants, individual differences in birds and site of encounters in relation to Black-cap < Parus gambeli (con't.) winter ranges." Franzreb (1976), observation of unsuccess- Jk ful attempt by a pair of violet-green Swallows to displace W a pair of Mountain Chickadees from nest (with nestlings) in an Aspen tree. The Swallows were able to drive the owners away and enter the nest cavity for a short while, but the chickadees were able to regain possession. C. Parasitism IX STATUS A. Past population trends Grinnell and Miller (1944), P. g. inyoensis: "Resident. Locally common." P. £. baileyae; "Resident. Usually common, sometimes abundant. There is a slight, irregular, down-mountain spread of in- dividuals in fall and winter; the low country is occasionally reached." B. Present population status Small (1974) "common resident." C. Population limiting factors I W Winternitz (1976), "because woodpeckers are responsible for the holes in which non-drilling species nest, the nesting activities of Downy and Hairy Woodpeckers, Williamson's Sapsucker and Common Flickers are potentially limiting to the Mountain Chickadee." D. Environmental quality: adverse impacts E. Potential for endangered status * Parus gambeli (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Barlow, C. 1901. Some characteristics of the Mountain Chickadee. Condor 3:111-114. Behle, W. H. 1956. A systematic review of the Mountain Chickadee. Condor 58:51-70. Bent, A. C. 1946. Life histories of North American jays, crows and titmice. Part 2. U.S. Nat. Mus. Bull. 191: 361-367. Bock, C. E. 1969. Intra- vs. interspecific aggression in Pygmy Nuthatch flocks. Ecology 59(5) : 903-905. Dixon, K. L. 1961. IN Vertebrate Speciation Blair, W. F. (Ed.) pp. 179-216. U. of Texas, Austin, Texas. Dixon, K. L. 1975. Mountain Chickadee survives a decade. Western Birds 6:162. Dixon, K. L. and J. D. Gilbert. 1964. Altitudinal migration in the Mountain Chickadee. Condor 66:61-64. Dixon, K. L. , R. A. Stefanski and F. N. Folks. 1970. Acoustic signals in the mating of Mountain and Black- capped Chicka- dees. Auk 87:322-328. Franzreb, K. E. 1975. Avian densities in a mixed-coniferous forest, Thomas Creek, White Mountains, Arizona. Western Birds 6:101-105. Franzreb, K. E. 1976. A comparison of variable strip transect and spot-map methods for censusing avian populations in a mixed-coniferous forest. Condor 78:360-363. Franzreb, K. E. 1976. Nest site competition between Mountain Chickadees and Violet-green Swallows. Auk 93:836-837. Grinnell, J. 1908. The biota of the San Bernardino Mountains. Univ. California Publ. Zool. 5:1-170. Grinnell, J. and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. 608 pp. Jaeger, E. C. 1947. Use of the creosote bush by birds of the southern California deserts. Condor 49:126-127. < Parus gambeii (con't. ) Laudenslayer , W. F. , Jr., and R. P. Balda. 1976. Breeding bird use of a pinyon- juniper-ponderosa pine ecotone. Auk 93:571-586 Miller, A. H. 1940. A transition island in the Mohave Desert. Condor 42:161-163. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. 50:531-624. Minock, M. E. 19 71. Social relationships among Mountain Chickadees (Parus gambeii). Condor 73:118-120. Minock, M. E. 1972. Interspecific aggression between Black- capped and Mountain Chickadees at winter feeding stations. Condor 74:454-461. Peters, J. L. 1960. Checklist of birds of the world. Vol. 9. (R. Paynter, Jr., and C. Vaurie, eds . ) Mus . Comp. Zool., Cambridge, Mass. 50 6 pp. Peterson, R. T. 19 61. Field guide to western birds. 2nd Edition. Houghton Mifflin Co., Boston. 366 pp. Ridgway, R. 1904. The birds of North and Middle America. Part 3. Bull. U.S. Nat. Mus. No. 50. Small, A. 1974. The birds of California. Macmillan Co., New York. Weydemeyer, W. 1975. Half-century record of the breeding birds of the fortine area, Montana: nesting data and population status. Condor 77:281-287. Winternitz , B. L. 19 76. Temporal change and habitat preference of some montane breeding birds. Condor 78:383-39 3. Udvardy, M. D. F. 1977. Audubon Society field guide to North American birds - western region. Knopf Co., New York. < • • • NORTHERN BROAD-TAILED HUMMINGBIRD Selasphorus platycercus S. p_. platycercus I TAXONOMY A. Type description AOU (1957), Trochilus platycercus Swainson, Phil. Mag., n.s., 1, no. 6, June 1827, p. 441. (No locality given = Mexico) . B. Current systematic treatments Peters (1945) recognizes eight species in genus Selasphorus ; two subspecies of S. platycercus (platycercus, guatemaiae; . Apodiformes: TrochTlidae. C. Synonomies of scientific nomenclature AOU (1957), Trochilus platycercus Swainson. D. Synonomies of vernacular nomenclature II DESCRIPTION A. External morphology of adults Ridgway (1911), detailed description of adults, including plumage, soft parts and measurements. Peterson (1961) 'Male: Black-green; throat bright rose-red. Female: . . . sides tinged with buffy; touch of rufous at sides of tail (near base when spread)." Dawson (1923), describes gorget of male as aster purple to amaranth purple. Upper parts shining green with brassy reflections; tail chiefly black, with violet reflections. Adult female similar but without purple gorget and lacking the shining green of breasts and sides. Also, female averages slightly larger. B. External morphology of subadult age classes Ridgway (1911), "Young male--similar to adult female but feathers of upper parts (especially rump and upper tail- coverts) indistinctly margined terminally with pale brownish buff or cinnamon, and lateral rectrices with much less of cinnamomeous on basal portion. Young female-- similar to young male but rectrices as in adult female." C. Distinguishing characteristics Interspecific - Peterson (1961) Male recognized by shrill trilling of wings as it flies. Lacks rufous coloration of Selasphorus platycercus ( con ' t . ) *- male Rufous and Allen's; lacks red crown of male Anna's; lacks orange-red throat of Ruby- throated. Female larger than female Black- chin. Intraspecific - III GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) "From east central California, northern Nevada, northern Wyoming, eastern Colorado, New Mexico, and south- western Texas to southern Mexico and the highlands of Guate- mala." jS. p_. platycercus: "Breeds from the mountains of east- central California (Inyo region) , northern Nevada, northern Utah, and northern Wyoming (Yellowstone National Park, Midwest) south to southeastern California (Clark Mountain), northeastern Sonora (Sierra de Oposura). Guana- juato, Mexico, Districto Federal, and southwestern Texas ( Chi so s Mountains ) . " B. California distribution of the species Small (1974) "this Rocky Mountain and Great Basin humming- bird is normally found only in the White, Panamint, Clark Mk and New York Mountains along the eastern border of the ^^ state." Males sighted in Inyo County and in the San Bernar- dino Mountains, both in May, indicate they may breed else- where in California. Johnson and Garrett (1974), reports sightings in San Bernardino Mountains. "Although occurrence ...could be strictly casual, the species may be preparing to colonize." C. California desert distribution Dawson (1923), "Summer resident in the timbered desert ranges of eastern California — at least the White Mountains and the Inyo range, probably the Panamints, Argus, Amargosa, etc." Miller (1951) Inyo Mountains. Grinnell and Miller (1944), "White and Inyo Mountains in Mono and Inyo Counties; the Grapevine Mountains, Inyo County; and Clark Mountains, San Bernardino County." D. Seasonal variations in distribution AOU (1957), "Winters from central Mexico southward. .. re- corded south to Oaxaca." • • Selasphorus platycercus (con't.) IV HABITAT A. Biotopic affinities Small (1974), "pinon- juniper woodland." Miller (1940), "especially numerous in the tingles of Garrya f lavescens from 6000 ft. upward on both north and south slopes of the mountain." Bent (1940) "lodge-pole pine forest... close to mountain streams." Miller (1951) Upper Sonoran and Transition zones. Grinnell and Miller (1944), "Upper Sonoran belt of pinon, juniper, and mountain mohogany, those trees of usual open stand, with xerophilous shrubbery interspersed. Especially favored is the vicinity of thickets, as of willow Garrya, along wet or dry stream courses." B. Altitudinal range Hall (193 ), one collected 7800 ft. in Snake Mountains, White Pine Co., Nevada. Wauer (1964), observed at 6000 ft. Panamint Mtns. C. Home range size D. Territory requirements Perch sites - Woodbury and Sugden (1938), "on twigs on the sides of either trees or bushes (never on top) .. .favorite perches were located on the inner sides of trees around the border of the area (of territory), or on bushes from which he could see the surrounding trees." Courtship and mating sites - Miller (1946) "Where this plant ( Garrya f lavescens) formed thickets over digwater courses, males were stationed and diving over females." Nest sites - Dawson (1923), "A cup of felted plant-downs, often white, not otherwise lined, but covered externally with lichens, dead leaves, or bark- shreds, held in place by cobwebs; placed 3 to 20 feet high on twigs, horizontal branches, or variously, in bushes or trees, usually near water. " E. Special habitat requirements Lyon (1973), "hummingbird territorial systems are often organized around food resources, usually nectar." F. Seasonal changes in habitat requirements Bendire (1895), "By the time the young are large enough to leave the nest the majority of the flowers have ceased Selasphoms platycercus (con't.) blooming, and as the country begins to dry up... retire to higher altitudes in the mountain parks where everything is now as green and bright looking as it was in the lower valleys two or three months earlier." V FOOD A. Food preferences Waser (1976), reported that nectar of Delphinium nelsoni (Green), D. barbeyi Huth. , Ipomupsis aggregata (V. grant) and Castilleja mmiata (Dougl. ) Cottam ( 1941) "seen feeding on oozing maple sap from holes that had been recently drilled by a Red-naped Sapsucker." Bent (1940) "small spiders and minute insects of the orders Diptera, Hymenoptera, Hemiptera, Co leopt era. . .which it finds in the flowers." B. Foraging areas C. Foraging strategies Linsdale (1938) "feeding upon flying insects caught in the air... after a poise the bird would dart 3 feet after an insect, then poise and go after another. This was repeated half a dozen times, the bird being about 10 feet above the ground." D. Feeding Phenology Bent (1940) "The young are fed at first on regurgitated, semidigested food, but as they grow older they are given an increasing amount of minute insects." E. Energy requirements Calder and Booser (1973) "high ratios of surface (heat dis- sipating) to volume (heat producing) , intense metabolism, and slight insulation. .. energy reserves of a hummingbird must be sufficient to meet the costs of nocturnal maintenance and the resumption of foraging at daybreak. A limited supply can be conserved by entry into hypothermic torpor, wherein the normal 38° to 43 °C range in body temperature is abandoned and heat production is reduced during the nocturnal fast." Reports of incident of hypothermic torpor by incubating female at night. Discussed ecological signi- ficance of this strategy. VI REPRODUCTION A. Age at first breeding B. Territorial behavior f Selasphorus platycercus (con't.) C. Courtship and mating behavior Woodbury and Sugden (1938), "male. . .dancing in the air with her (female), occasionally touching bills, but more often performing his characteristic dives, in which he would spiral up about as high as the tree tops and then dive rapidly toward the ground making a sweeping curve at the bottom and come up again on rapidly beating wings. The descent was generally marked by a peculiar rattling sound which gave way at the bottom to a decided duck just as the sweep reversed and he started to rise." Knox (1944), "The female would sit quietly on a branch somewhere, and a male would suddenly zoom up past her, so close as nearly to knock her from her perch, and straight on upwards until he was a speck in the sky..." "Occasionally. . .he would do a series of figure-eights and double loops. D. Nesting phenology Dawson (1923), May, June, July, two broods. Waser (1976), work in Gothic, Colorado, showed that 1) the start of hum- mingbird reproduction corresponds in time and space with flowering of the earliest nectar source, 2) peak brooding activity at these nests corresponds with peak density of ♦other main food sources, 3) total duration of summertime flowering of the main food plants is implicated as a force that compresses the initiation of nesting toward the earliest possible date. E. Length of incubation period Bent (1940) "about 14 days" F. Length of nestling period G. Growth rates H. Post-breeding behavior Bendire (1895) "By the time the young are large enough to leave the nest. .. retire to higher altitudes in the mountain parks. .. raise their second broods under nearly similar conditions as the first." VII POPULATION PARAMETERS A. Clutch size Dawson (1923), two eggs; two broods. A B. Fledging success Waser (1977) "observed mean productivity of 1.15 chicks per nest in 52 nests in 1971, 1972, 1973." Selasphorus platycercus (con't.) C. Mortality rates per age class D. Longevity Waser (1977), based on banding records of local population at Rocky Mountain Biological Laboratory, estimate mean minimum life span equal to 30 months. E. Seasonal abundance F. Habitat density figures Miller (1940) "especially numerous in the tangles of Garrya f lave-scens ... as many as five males were counted in one patch of brush 200 yards long." Franzreb (1975), reports 14.3 average breeding birds per 100 hectares, Thomas Creek, White Mountains, Arizona, summer 1973. II INTERSPECIFIC INTERACTIONS A. Predation B. Competition Lyon (1973) "Displays and overt aggression were usually directed towards conspecifics, but bees feeding on Iris, especially Bombus and Xylocopa, were frequently attacked and often successfully ejected from the territory. Feeding butterflies often appeared to be deliberately supplanted but were never pursued." Dunford and Dunford (1972), des- cribes territorial encounter _S. rufus at cluster of Penstemon. Calder (1972), observed S. platycercus removing materials from nest of Contopus sordTdulus ; Vireo gilvus removing materials from nest" of _S. platycercus . C. Parasitism IX STATUS A. Past population trends Grinnell and Miller (1944), "Summer resident. Sparse." B. Present population status C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status Selasphonis platycercus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bendire, C. M. 1895. Life histories of North American birds. U.S. Nat. Mus. Spec. Bull. No. 3. Bent, A. C. 1940. Life histories of North American cuckoos, goatsuckers, hummingbirds and their allies. U.S. Nat. Mus. Bull. No. 176. Calder, W. A. 1972. Piracy of nesting materials from and by the Broad- tailed Hummingbird. Condor 74:485. Calder, W. A. and J. Booser. 1973. Hypothermia of Broad- tailed Hummingbirds during incubation in nature with ecological correlations. Science 180:751-753. Cottam, C. 1941. Incubation feeding of Calliope Hummingbird. Auk 58:59-60. Dawson, W. L. 1923. The birds of California. Vol. 2. South I Moulton Co., San Francisco. Dunford, C. and E. Dunford. 1972. Interspecific aggression of resident Broad- tailed and migrant Rufous Hummingbirds. Condor 74:479. Franzreb, K. E. 1975. Avian densities in a mixed-coniferous forest, Thomas Creek, White Mountains, Arizona. Western Birds 6:101-105. Grinnell, J. and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. 608 pp. Hall, R. E. 1938. Broad-tailed Hummingbird attracted to food of the Red-naped Sapsucker. Condor 40:264. Johnson, N. K. and K. L. Garrett. 1974. Interior bird species expand breeding ranges into southern California. Western Birds 5:45-56. Knox, D. A. 1944. Summer birds of the Gothic area, Gunnison County, Colorado. Auk 61:19-30. Linsdale, J. M. 1938. Environmental responses of vertebrates in the Great Basin. Amer. Midi. Nat. 19:1-206. 8 Selasphorus platycercus (con't.) Lyon, D. L. 1973. Territorial and feeding activity of Broad- tailed Hummingbirds (Selasphorus platycercus) in Iris missouriensis. Condor 75:346-349. Miller, A. H. 1940. A transition island in the Mohave Desert. Condor 42:161-163. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. 50:531- 624. Peters, J. L. 1945. Checklist of birds of the world. Vol. 5. Mus. Comp. Zool., Cambridge, Massachusetts. 306 pp. Peterson, R. T. 1961. A field guide to western birds. Hough- ton Mifflin Co., Boston. 309 pp. Ridgway, R. 1911. The birds of North and Middle America. Part 5. Bull. U.S. Nat. Mus. No. 50. Small, A. 1974. The birds of California. Macmillan Co., New York. Waser, N. M. 1976. Food supply and nest timing of Broad- ^^ tailed Hummingbirds in the Rocky Mountains. Condor 78: 41 133-134. Waser, N. M. and D. W. Inouye. 1977. Implication of recaptures of Broad- tailed Hummingbirds banded in Colorado. Auk 94: 393-395. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Woodbury, A. M. and J. W. Sugden. 1938. An hour in the life of a Broad-tailed Hummingbird. Condor 40:160-162. NORTHERN GRAY- HEADED JUNCO Junco c. caniceps t I TAXONOMY A. Type description Junco caniceps caniceps - AOU (1957) Struthus caniceps Woodhouse, Proc. Acad. Nat. Sci. Philadelphia, Nov. -Dec. 1852 (Feb. 7, 1853), p. 202. (San Francisco Mountain, New Mexico (=Arizona) . ) B. Current systematic treatments AOU (1957) considers the Gray-headed Junco a member of the avian Order Passeriformes, Family Fringillidae (grosbeaks, finches, sparrows, and buntings), Subfamily Emberizinae. Hellmayr (1938) makes note of the close relationships between J. phaeonotus (=caniceps) and J. oreganus (=hyemalis). He lists the race caniceps as a race of the species J. oreganus. Paynter and Storer (1970) also consider caniceps to be a race of J. hyemalis, although they state that "there remains much to 'Be understood "in this complex. Johnson (1965) noted interbreeding of J. oreganus thurberi and J. c. caniceps in southern Nevada; tKis hybrid has been describee! as a race (J. o. mutabilis) . Miller (1939) gives a detailed discussion of Hybridization in J. caniceps. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Junco phaeonotus. Miller (1941) lists Struthus caniceps ; Junco annectens ; J. cinereus caniceps; J. hiemalis caniceps; J. oreganus caniceps. D. Synonomies of vernacular nomenclature Ligon (1961), Red-backed Junco; Mexican Junco. II DESCRIPTION A. External morhpology of adults Miller and Stebbins (1964), "A sparrow with the white lateral tail feathers of the junco group. Head and flanks light, uniform gray, the flantcs somewhat paler. Back gray, except for well defined rust-red patch in center; belly white; orbital area blackish." Ridgway (1901) adds that the bill is "pinkish in life, iris brown; tarsi pale yellowish brown, toes darker." Miller (1941) gives a detailed description of most races within the Genus Junco , including caniceps. Junco caniceps (con't.) B. External morphology of subadult age classes Young in first winter are essentially like adults, but the gray of chest and other parts decidedly paler; reddish brown of back duller (Ridgway 1901). C. Distinguishing characteristics Interspecific - Bent (1968), "Juncos usually are distin- guished from other small birds occurring in their range by ...white outer tail feathers and the characteristic "tic" notes... in flight." Peterson (1961), "similar species: (l) Oregon Junco has rusty or pink-buff sides, rusty wings; male has blackish hood. (2) Mexican Junco has yellow eye. (3) Hybrids occur (Gray-headed X Oregon)." Intraspecific - Ridgway (1901) described adult caniceps as "sexes alike"; adult male, length 152.4 mm; wing 84.58; tail 72.14; and adult female, length 114.78 mm; wing 78.74; tail 66.55." Ligon (1961), "6-6.5 inches long. Color pattern of sexes alike." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) gives the overall range of the Gray-headed Junco as "North- central Nevada, northern Utah, and southern Wyoming south to central Arizona, southern New Mexico, and western Texas. Winters in breeding range and south to southern California, northern Sinaloa, and northern Durango." The range of Junco c. caniceps was described by the AOU (1957) as "Breeds in mountains from southern Idaho, Nevada, Utah, and southern Wyoming south through central and east central Nevada, the White Mountains of California, Utah, and western and central Colorado to northern Arizona and northern New Mexico." B. California distribution of the species Grinnell and Miller (1944) describe range as "In summer, two mountain areas on southern Nevada border: Clark Moun- tain, eastern San Bernardino County. .. (and) Grapevine Mountains, Inyo County. In winter, coastal district from Los Angeles County to San Diego County." Small (1974) also gives Clark and Grapevine Mountains as California breeding areas; calls this junco a "vary rare winter visitor elsewhere." Cardiff (1949) noted the rare occurrence of a Gray-headed Junco on the west slope of the San Gabriel Mountains (6 November 1948). Dickey (1922) felt that Gray- heads are normally present in the San Bernardino Mountains during winter. Kaeding (1899) discusses the occurrence of Junco in California; only one record of caniceps was listed at that time. Junco caniceps (con't.) C. California desert distribution Miller and Stebbins (1964) called this junco a "rare winter visitant" in Joshua Tree National Monument. Recorded from Upper Covington Flat (4 Nov.) and Pinyon Wells (15, 16 Oct.) In the Providence Mountains, Johnson et al. (1948) reported that a "small area on the northwest side of Clark Mountain appeared to be the only suitable breeding place for juncos of any kind." Van Rossem (1936) collected an immature cani- ceps in the Charleston Mountains near Death Valley, Calif- ornia, in October. Wauer (1964) found an apparent hybrid Gray-headed X Oregon junco nesting at 10,500 feet in the Panamint Mountains. Miller and Russell (1956) took non- hybrid J. c. caniceps during breeding season in the White Mountains." They noted, however, that introgression between J. caniceps and J. oreganis thurberi is taking place in this location. Monson (1949) collected an immature male Gray- head near Topock on the lower Colorado, "the first record for the Colorado Valley" (15 October 1946). Miller (1945) found J. c. caniceps breeding on Clark, Potosi and Charles- ton Mountains. D. Seasonal variations in distribution AOU (1957) states that Junco c. caniceps "Winters in lower mountains and plains of breeding area, north to northern Utah, northern Colorado; and from western Nebraska and eastern Colorado south to northern Sonora, northern Sinaloa, northern Durango, and western Texas; rarely to southern California (Pasadena, San Diego R. , Potholes)." Miller and Stebbins (1964), "This. .. junco occasionally migrates southwest into southern California, although chiefly it is found east of the lower Colorado River Valley in winter." Although the study was based on Oregon Juncos, Wolf son (1942) gives a detailed study of migration in juncos IV HABITAT A. Biotopic affinities In California, Small (1974) gives California habitat as "pinon- juniper woodland, montane forests of white fir." Miller (l941) noted that "Associations in which it breeds includes coniferous forest types dominated either by spruce (Picea) , Pseudotsuga, Pinus contorta, P. ponderosa, P. flexilis, or fir (AEies). It also breeds m pure stands of aspen and of mountain mahogany." In Colorado, Winternitz (1976) noted these juncos in aspen-willow (287Q of observa- tions), ponderosa pine (24%), and Douglas fir (21.3%) during breeding season. Junco caniceps (con't.) B. Altitudinal range Bent (1968) noted breeding in various western states from about 6,000 to 10,000 feet. In New Mexico, caniceps nests from 6,500 to 9,500 feet (Ligon 1961). In Colorado, Johnston (1943) found gray-heads nesting from 8,000 feet to timberline. C. Home range size In Colorado, Rockwell (1910) found several nests of caniceps which were usually placed about 100 yards apart. D. Territory requirements Perch sites - Courtship and mating sites - Bent (1968) reported that during courtship "The male always chose the top of a tall pine as a singing post." Nest sites - "The Gray-headed Junco is with rare exceptions a ground nester" (Bent 1968*). In Colorado, Johnston (1943) found nests "on the ground and well- concealed, but in a variety of cover." E. Special habitat requirements Bent (1968) recounts that "The spotted distribution of this junco must be emphasized. It inhabits... a series of mountain- top islands above 7,000 feet." In Idaho, Burleigh (1972) noted that caniceps "has rather exacting requirements. .. it occurs. . .only on the higher ridges (between 6,000 and 7,000 feet) characterized by stretches of stunted junipers and extensive thickets of mountain mahogany." F. Seasonal changes in habitat requirements Grinnell and Miller (1944) found that this race drops down from the mountains and is in association with other juncos in such places as open oak woodlands. V FOOD A. Food preferences Bent (1968) noted that these juncos feed on ail available plant seeds, grasses, herbs, and shrubs; insects are also taken while feeding on the ground. • Junco caniceps (con't.) B. Foraging areas Bent (1968), "Juncos are mainly terrestrial and obtain practically all of their food on or very near the ground." C. Foraging strategies "Juncos, like many other members of the sparrow family, are primarily ground- feeding seed eaters" (Martin et al. 1951). D. Feeding phenology Martin et al. (1951) reported that juncos "are partial to seeds of common weeds. In summer, insects constitute about half or more of their diet." E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Bent (1968) noted that "observations of territorial conflict between Gray-headed Juncos are few." C. Courtship and mating behavior Bent (1968) noted that "the mating behavior of the Gray- headed Junco probably differs little, if at all, from that of the better known Oregon and Slate-colored juncos... Considerable activity, consisting chiefly of pursuit and nest-building, was observed." In New Mexico, Tatschl (1967) reported singing males between 19 March and 27 July. D. Nesting phenology Bent (1968) gives Colorado egg dated as: 45 records, 8 May to 18 July; 24 records, 16 June to 4 July. In northern Arizona, Hargrove (1936) recorded 3 broods raised in one season (one brood hatched in early June, another in late July, and the last in late August) . E. Length of incubation period Bent (1968) lists a 11 or 12 day incubation period. Miller (1938) gave an incubation period of 12 days for a set of eggs from a Gray-head X Oregon junco mating in captivity. Junco caniceps (con't.) F. Length of nestling period Bent (1968) recounted that the young spend 10-13 days in the nest after hatching. G. Growth rates The development of young was summarized by Phillips (in Bent 1968): at 3 days, the 4 young weighed 27.5 grams (still nearly naked, eyes not open); at 5 days, weight 44.5 grams; at 6 days, eyes opening, weight 48.0 grams; at 7 days, eyes open, feathers of belly tracts becoming prominent, weight 60.5 grams; at 10 days, weight 70 grams, young began to fledge. H. Post-breeding behavior "After completing their breeding activities the northern caniceps form small groups, presumably of adults and the young of the season, and start a southward movement" (Bent 1968). VII POPULATION PARAMETERS A. Clutch size Bert (1968), "The Gray-headed Junco lays from 3 to 5 slightly glossy eggs." Ligon (1961), "Eggs: 4; greenish white, marked with lilac and reddish brown around larger end." B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abnndance In Wyoming, Finzel (1964) noted an increase of Gray-headed Juncos from 1.0 individuals per 40 acres in breeding season to 3.0 individuals per 40 acres immediately following breed- ing. F. Habitat density figures In a Colorado study, Winternitz (1976) found an average of 12.0 pair of caniceps breeding per 40 ha (montane study area). In a Colorado Douglas fir-ponderosa pine study, Snyder (1950) found 36 breeding pairs of Gray-heads per 40 ha; this species was twice as common as the next most numerous species. The breeding density dropped to 5 pairs per 40 ha in lodgepole pine, however. At 9,700 feet in Colorado, McHugh (1948) recorded 3-4 breeding pairs on a 22 acre study r * Junco caniceps (con't.) plot. On Clark Mountain (San Bernardino County, California), Miller (1940) found 2 pairs breeding in the 40 acres of Transition Zone timber on the mountain. VIII INTERSPECIFIC INTERACTIONS A. Predation Bent (1968) stated that the Gray-headed Junco falls prey to those predators common to other small birds. Screech and Pygmy owls, Sharp-skinned Hawks, and Northern Shrikes take j uncos. B. Competition In Colorado, Hering (1948) noted that "two breeding pairs remained near each other throughout the season. The males of the... two pairs sang rather often, but both families fed ...without any apparent conflict." C. Parasitism Neither Friedmann (1963) nor Friedmann et al. (1977) list caniceps as a victim of cowbird parasitism. However, J. hy emails is listed as a cowbird victim. I IX STATUS A. Past population trends Grinnell and Miller (1944) described this race in California as a "rare summer resident. . .along eastern border. Occasional winter visitant to coastal southern section." B. Present population status C. Population limiting factors Concerning J. c. caniceps, Miller (1939) felt that "Its breeding range is limited almost completely by unfavorable desert or plains regions." D. Environmental quality: adverse impacts E. Potential for endangered status Junco caniceps (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Ed. American Ornithologists' Union, Baltimore, MD. 691 pp. Bent, A. C. 1968. Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows, and allies. Part 2. U.S. Nat. Mus. Bull. 237. Burleigh, T. D. 1972. Birds of Idaho. Caxton Printers, Ltd., Caldwell, Idaho. 467 pp. Cardiff, E. E. 1949. Sixth record of Gray-headed Junco on Pacific slope of southern California. Condor 51:231. Dickey, D. R. 1922. A third record of the Gray-headed Junco in California. Condor 24:137-138. Finzel, J. E. 1964. Avian populations of four herbaceous communities in southeastern Wyoming. Condor 66:496-510. * Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233:1-276. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the parasitic cowbirds. Smithsonian Contrib. Zool. 235. 75 pp. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp. Hargrave, L. L. 1936. Three broods of Red-backed Junco in one season. Condor 38:57-59. Hellmayr, C. E. 1938. Catalogue of birds of the Americas. Vol. 13, Part 11. Field Mus. Nat. Hist. Zool. Ser. 430. 662 pp. Hering, L. 1948. Nesting birds of the Black Forest, Colorado. Condor 50:49-56. Johnson, D. H. , M. D. Bryant and A. H. Miller. 1948. Verte- brate animals of the Providence Mountains areas of Calif- ornia. Univ. California Publ. Zool. 48:221-376. Johnson, N. K. 1965. The breeding avifaunas of the Sheep and Spring ranges in southern Nevada. Condor 67:93-124. f Junco caniceps (con't.) Johnston, V. R. 1943. An ecological study of nesting birds in the vicinity of Boulder, Colorado. Condor 45:61-68. Kaeding, H. B. 1899. The genus Junco in California. Condor 1:79-81. Ligon, J. S. 1961. New Mexico birds. Univ. New Mexico Press, Albuquerque. 360 pp. Martin, A. C, H. S. Zim and A. L. Nelson. 1951. American wildlife and plants. McGraw-Hill Book Co., Inc. N.Y. 500 pp. McHugh, T. C. 1948. A nesting census from the subalpine belt of Colorado. Condor 50:227-228. Miller, A. H. 1938. Hybridization of juncos in captivity. Condor 40:92-93. Miller, A. H. 1939. Analysis of some hybrid populations of juncos. Condor 41:211-214. Miller, A. H. 1940. A transition island in the Mohave Desert. Condor 42:161-163. Miller, A. H. 1941. Speciation in the avian Genus Junco . Univ. California Publ. Zool. 44:173-434. Miller, A. H. 1945. Birds of the yellow pine association of Potosi Mountain, southern Nevada. Condor 47:130-131. Miller, A. H. and W. C. Russell. 1956. Distributional data on the birds of the White Mountains of California and Nevada. Condor 58:75-77. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Monson, G. 1949. Recent notes from the lower Colorado River valley of Arizona and California. Condor 51:262-265. Paynter, R. A., Jr. and R. W. Storer. 1970. Checklist of birds of the world. Vol. 13. Mus. Comp. Zool. , Cambridge, Mass. 443 pp. Peterson, R. T. 1961. A field guide to western birds. Second Ed. Houghton Mifflin Co., Boston. 366 pp. Ridgway, R. 1901. The birds of North and Middle America. Part 1. U.S. Nat. Mus. Bull. 50. 715 pp. 10 Junco caniceps (con't.) Rockwell, R. B. 1910. Nesting of the Gray-headed Junco. Condor 12:164-165. Small, A. 1974. The birds of California. Winchester Press, N.Y. 310 pp. Snyder, D. P. 1950. Bird communities in the coniferous forest biome. Condor 52:17-27. Tatschl, J. L. 1967. Breeding birds of the Sandia Mountains and their ecological distributions. Condor 69:479-490. Van Rossem, A. J. 1936. Birds of the Charleston Mountains, Nevada. Pacific Coast Avifauna No. 24. 65 pp. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Wintermitz, B. L. 1976. Temporal chance and habitat preference of some montane breeding birds. Condor 78:383-393. Wolf son, A. 1942. Regulation of spring migration in juncos. Condor 44:237-263. < ♦ NORTHERN ORIOLE Icterus galbula I TAXONOMY A. Type description AOU (1957) Icterus galbula bullockii (Swainson): Xanthornus bullockii Swainson, Phi i. Mag., n.s., 1. no. 6, June 182/, p. 436. ("Table land = Real del Monte, Hidalgo, Mexico.) Icterus galbula parvus : Icterus bullockii parvus van Rossem, Occ. Fap. Mus. Zool. Louisiana State Univ. , no. 21., Oct. 25, 1945, p. 237. (Jacumba, San Diego County, California.) B. Current systematic treatments AOU (1957) places .1. galbula in the Order Passeriformes, Family Icteridae, with three subspecies. Dawson (1923) refers only to I. bullockii in California. Bent (1958) list I. b. bullockii and I. b. parvus. Robbins et al. (19667 lTst I. galbula as the eastern and central species and I. bullockii as the western species. Mayr and Short (197TJ), I. galbula: "This species is comprised of three morphologically distinct groups, the galbula, bullockii, and abeillei (Mexico). These interbreed to form hybrid zones in the Great Plains (galbula, bullockii) and in Durango Mexico (bullockii, abeillei)^ All are considered conspecific." C. Synonomies of scientific nomenclature AOU (1957), I. galbula bullockii - Icterus bullockii, Xanthornus bullockii; I. g. parvus - I. bullockii parvus. Grinnell and Miller (1^"44), I. g. bulTocFii - Hyphantes bullockii, Xanthornis bullockii, Yphantes bullockii, I. b. bullockii. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944) - Bullock's Oriole, Western Oriole. Bent (1958) - Baltimore Oriole. II DESCRIPTION A. External morphology of adults Baird et al. (1905): "Icterus. Head all round deep black, sharply defined against the yellow of the nape; wings black, with or without white markings. Body generally, including lesser wing-coverts, deep greenish-yellow. I. bullockii. Head mainly black, with an orange or yellow superciliary | stripe, and a broader one beneath the eye, cutting off the f black of the throat with a narrow stripe; tail orange or yellow, the feathers with black at ends; greater coverts Icterus gal bul a (con't.) with outer webs wholly white, and middle coverts entirely- white, producing a large conspicuous longitudinal patch on the wing; tertials and secondaries broadly edged with white, primaries more narrowly striped with the same. Rump grayish orange; sides and flanks deep orange; forehead and auriculars orange; a broad supraloral stripe of the same. Xanthic tints deep orange, with a reddish tinge on the breast. Tail very slightly graduated. Dawson (1923): "Adult male - Black, white and orange; bill, lore a line through the eye, and throat (narrowly) jet black; pileum, back, scapulars, lesser wing-coverts, primary coverts and tertials, chiefly black, or with a little yellowish skirting; remiges black edged with white; middle and greater coverts, continuous with edging of tertials and secondaries, white forming a large patch; tail chiefly cadmium-yellow but central pair of retrices black on exposed area, and remaining pairs tipped with blackish; remaining plumage, including supraloral areas continuous with superciliaries, orange, most intense on sides of throat and chest, shading on lower breast to cadmium-yellow posteriorly; rump washed with olivaceous. In younger adults the orange is less intense, and the tail is more extensively black. Bill black above and bluish below; feet and legs dusky-horn color. Adult female - above drab-gray, clearest on rump and upper tail coverts; washed with yellow on head; wings fuscous with whitish edging; pattern of white in coverts of male retained, but much reduced in area; tail nearly uniform dusky-orange; sides of throat and chest wax-yellow chin and throat and remaining underparts sordid white or pale creamy-buff; the under tail coverts usually tinged with yellow. Sibley and Short (1964) give extensive color descriptions and measurements for Baltimore and Bullock's Orioles. Corbin and Sibley (1977) describe the hybridization of Bullock's and Baltimore Orioles. B. External morphology of subadult age classes Baird et al. (1905): "Young male with black replaced by greenish-yellow, that on the throat persistent; female with- out this. Dawson (1923): "Immature - like adult female; yellow of head and throat stronger." Bent (1958) says young obtain adult winter plumage in July after their first year, but the feathers of the back are narrowly edged with dull orange which is not present in older birds. t Icterus galbula (con't.) G. Distinguishing characteristics Intraspecific - Bent (1958) describes I. g. parvus as being smaller than I, g. bullockii. Peterson (T961) describes the differences between Baltimore and Bullock's Orioles. Mistra and Short (1974) report on the hybridization of 1^. f. bullockii and I. g. galbula in the Great Plains, idgway (1915) provides a key to the Icterids. Rising (1973) discusses morphological variation of Baltimore and Bullock's Orioles. Interspecific - Dawson (1923): "Top of head black and under- sides of tail yellow as contrasted with the Arizona Hooded Oriole. Note slender, blackish bill of female, as contrasted with heavy, light-colored bill of Western Tanager." Willett (1951): "Bill shorter and less curved than (Hooded). Male with black back, top of head, and throat patch, a large white wing-patch, and bright orange underparts. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), 1^ £. bullockii: "Breeds from southern British k Columbia, east of the coastal ranges, northwestern Montana, V southern Alberta, southwestern Saskatchewan, northeastern Montana, southwestern North Dakota, western South Dakota, western Nebraska, western Kansas, western Oklahoma, and central Texas south to central and southern interior Calif- ornia, southern Nevada, southwestern Utah, central and cen- tral-southern Arizona, northeastern Sonora, probably northern Chihuahua, central Coahuila, and southern Texas." I. g. parvus : "Breeds from central western and southern California, extreme southern Nevada, and western Arizona, south to northern Baja California and northwestern Sonora." B. California distribution of the species Dawson (1923): "Abundant summer resident in many parts of the state - from the Nevada line to the seacoast, and from the Oregon line to the Mexican boundary. Of least abundance in the northwest coastal belt and on the Santa Barbara Islands. Centers of abundance are the interior valleys north of Tehachapi." Grinnell and Miller (1944), I. bullockii: "As breeding, all sections of the state except the islands, in coastal fog belt north of Sonoma County and areas of con- tinuous Montane forest." Small (1974): "Ranges in California for breeding - length of state except humid coastal coni- ferous forest, mountain forests." • Icterus galbula (con't.) C. California desert distribution Grinnell and Miller (1944) give records from Inyo, Kern, San Diego, San Bernardino Counties. Willett (1951) lists 3 orioles as resident in the southern California desert: California Hooded (I. cucullatus calif ornicus) , Bullock s (I_. bullockii) and "Scott's {I. parisorum) . Wauer (1964) reports Bullock ' s and Hooded Orioles breeding in the upper canyons of the Panamint Mountains. D. Seasonal variations in distribution AOU (1957), I. g. bullockii: "Winters from southern Sinaloa, Mexico, and FueDla south, west of the continental divide, to northwestern Costa Rica; casually north to central Calif- ornia, southern Texas and southern Louisiana." 1. g. parvus : "Winter range largely unknown, possibly winters sparingly in southern California and Arizona; pro- bably in central -we stern Mexico south to Guerrero." Bent (1958) gives a report from Alexander Skutch saying that I. bullockii arrives on its wintering grounds in Central America during the second week in September, and departs in April. I. g. bullockii winter range is given as above. Phillips et al. (1964) : "On migration prefers the same-broad leaved trees in open country, especially in the Lower Sonoran Zone." IV HABITAT A. Biotopic affinities Dawson (1923): "Of very general zonal and faunal preferences: breeds from Lower Sonoran up through Transition, and from riparian association on the deserts to the San Francisco Bay region. Grinnell and Miller (1944): "Riparian oak woodland, especially where trees are large and well spaced." Phillips et al. (1964): "Breeds commonly in cottonwood-willow associa- tion of the Sonoran Zones." Walcheck (1970) reported orioles nesting in cottonwood forest in Montana, and not in sage- brush shrubland, sagebrush grassland or pine- juniper wood- land. Gullion et al. (1959) note the occurrence of I, bullocki in the desert valleys and in the cottonwoods about springs in the desert ranges in Nevada. Wauer (1964) reports Bullock's and Hooded Orioles in the upper and lower canyons of the Panamint Mountains; in trees in the sidewashes and in the area just below the pinon- juniper woodland which is well watered compared to many other localities in these mountains . • • Icterus galbula (con't.) B. Altitudinal range Dawson (1923) says they occur from Lower Sonoran up through Transition. Wauer (1964) found Bullock's Orioles breeding 1,000 to 4,000 feet in the Panamint Mountains. C. Home range size D. Territory requirements Perch sites Courtship and mating sites Nest sites - Dawson (1923): "...deciduous trees, usually at moderate heights." Bent (1958) describes the usual nest- ing site as near the top of some fair sized tree, as a maple, white elm, apple, mesquite, birch. Grinnell and Miller (1944): "Sycamores, cottonwoods, willows, and deciduous oaks seem to be especially favored, but live oaks, orchard trees and occasionally conifers are used." Nests are placed 6 or more feet up, often in the middle area of trees. Schaefer (1976) found the placement and structure of nests to vary geographically, mainly because of differences in vegetation. E. Special habitat requirements Grinnell and Miller (1944) state that they seem to need a nearby water source. Gabrielson and Jewett (1940): "It is primarily a bird of river bottoms and farming districts. F. Seasonal changes in habitat requirements V FOOD A. Food preferences Bent (1958) reports caterpillars forming over 1/3 of the food supply. They also eat web worms, moth larvae, beetles, ants, wasps, spiders, snails, June berries, mulberries, blackberries, some seeds. Some problem has been noted with their pea-eating habit. B. Foraging areas Bent (1958) describes them feeding trees and sometimes on the wing as they chase an insect. Grinnell and Miller (1944) says they use adjacent open fields next to nesting trees, grass or brush covered, in addition to foraging in the crown of trees. 6 Icterus galbula (con't.) C. Foraging strategies D. Feeding phenology- Bent (1958) says during the winter they are found feeding in Central America on a considerable variety of animal and vegetable food. E. Energy requirements Bent (1958) writes an account of young being fed by regurgi- tation about every 20 minutes. VI REPRODUCTION A. Age at first breeding B. Territorial behavior Bent (1958): "...he defends his territory with great vigor and daring." The males arrive on their breeding grounds in full song and sing all day until incubation is underway when they subside. C. Courtship and mating behavior Bent (1958) describes the male sitting on a limb next to a female and bowing, spreading his tail and raising his wings while uttering "supplicating and seductive" notes. The female whistles 2 or 3 notes like the males during the nesting season. D. Nesting phenology Bent (1958): "...arrives in southern New England. . .about 10 May." Gabrielson and Jewett (1940): "Eggs are laid primarily from 16 May to 15 June," in Oregon. Gullion et al. (1959) report I. bullockii to arrive in Nevada as early as 16 April and leave in the beginning of September. E. Length of incubation period F. Length of nestling period Bent (1958) - 11 to 14 days. G. Growth rates H. Post-breeding behavior Bent (1958) comments that I. bullockii becomes quite quiet in August so even when they are still present it is hard to • Icterus galbula (con't.) find them. "Apparently old males do not remain with their families very long after the breeding season. VII POPULATION PARAMETERS A. Clutch size Dawson (1923) - usually 5. Bent (1958) - 4 to 6. B. Fledging success C. Mortality rates per age class Bent (1958) says that young are comparatively safe for the first 2 weeks of life when they remain concealed in their hanging basket nest. D. Longevity Kennard (1975) found the oldest 1^ galbula to be 7 years in a study of band returns. E. Seasonal abundance A F. Habitat density figures VIII INTERSPECIFIC INTERACTIONS A. Predation Bent (1958) list predators as: crows, Screech Owl, squirrels. Ashman (1977) noted a Northern Oriole eating a hummingbird on South Farallon Island. He did not know if the Oriole killed the hummingbird. B. Competition Bent (1958) reports I. bullockii nesting in the same tree with a wood peewee, an orchard oriole, kingbirds and other I. bullockii. It will battle with other species in actual physical combat. Whitmore (1977) in a study of habitat partitioning in a community of passerine birds and found Bullock's Oriole associated with Yellow and Audubon's Warblers, and Black-headed Grosbeaks in the high canopy. C. Parasitism Friedmann et al . (1977): "Experiments involving the addition of foreign eggs to nests that contained 2 or more oriole eggs demonstrated that this oriole is a rejecter species, though sometimes they do raise a cowbird. » Icterus galbula (con't.) IX STATUS A. Past population trends Bent (1958) gives an account of the spread of I. bullockii, allowed by the cutting of forests by settlers and subsequent growth of bushes. Anderson (1971) discusses the increase in number and range of I. £. galbula and I. £. bullockii caused by man's changes to the prairie in South Dakota. B. Present population status Weber (1976) comments on the increasingly common occurrence of I. g. galbula in northeastern British Columbia. I. £. bulTockii has always been fairly common there. C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status m « Icterus gal bul a (con't.) XI LITERATURE CITED American Ornithologists Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Anderson, B. W. 1971. Man's influence on hybridization in two avian species in South Dakota. Condor 73:342-347. Ashman, P. 1977. Northern (Bullock's) Oriole eats hummingbird. Western Birds 8:105. Austin, G. T. 1970. Breeding birds of desert riparian habitat in southern Nevada. Condor 72:431-436. Baird, S. F. , T. M. Brewer and R. Ridgway. 1905. A history of North American birds. Vol. 2. Little, Brown, and Co., Boston. Bent, A. C. 1958. Life histories of North American blackbirds, orioles, tanagers and allies. U.S. Natl. Mus. No. 211. Corbin, K. W. and C. G. Sibley. 1977. Rapid evolution in orioles of the genus Icterus. Condor 79:335-342. Dawson, W. L. 1923. The birds of California. Vol. 1. South Moulton, Co., Los Angeles. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the para- sitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Gabrielson, I. N. and S. G. Jewett. 1940. Birds of Oregon. Oregon State college, Corvallis. 650 pp. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific coast avifauna. No. 27. 608 pp. Gullion, G. W. , W. M. Pulich and F. G. Evenden. 1959. Notes on the occurrence of birds in southern Nevada. Condor 61:278-297. Mayr, E. and L. L. Short. 1970. Species taxa of North American birds. Publ. Nuttal Ornithological Club, No. 9. Mistra, R. K. and L. L. Short. 1974. A biometric analysis of oriole hybridization. Condor 76:137-146. Oberholser, H. C. 1974. The bird life of Texas. Vol. 2. Univ. of Texas Press, Austin. 10 Icterus galbula (con't.) Peterson, R. T. 1961. A field guide to western birds. Second Edition. Houghton Mifflin, Co., Boston. 366 pp. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. of Arizona Press, Tucson. 212 pp. Ridgway, R. 1915. A manual of North American birds. Fourth Edition. J. B. Lippencott Co., Philadelphia. 653 pp. Rising, J. D. 1973. Morphological variation and status of the orioles, Icterus galbula, I. bullockii and I, abeillei, in northern Great Plains and in Durango, Mexico. Can. J. Zool. 51:1267-1273. Robbins, C. S., B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Schaefer, V. H. 1976. Geographic variation in the placement and structure of oriole nests. Condor 78:443-448. Sibley, C. G. and L. L. Short. 1964. Hybridization in the orioles of the Great Plains. Condor 66:130-150. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Walcheck, K. C. 1970. Nesting bird ecology of four plant com- munities in the Missouri River Breaks, Montana. Wil. Bull. 82:370-382. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Weber, W. C. 1976. Mourning Warbler and Northern Oriole in northeastern British Columbia. Murrelet 57:68-69. Whitmore, R. C. 1977. Habitat partitioning in a community of passerine birds. Wil. Bull. 89:233-265. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Museum Zool. Series 6:1-39. ! PINON JAY Gymnorhinus cyanocephalus I. TAXONOMY A. Type description Gymnorhinus cyanocephalus - AOU (1957) Weid, Reise Nord- Amer. , vol. T, 1841, p. 22. (am Maria-River = between the Marias and Yellowstone rivers, Montana.). B. Current systematic treatments Hellmayr (1934) describes the Pinon Jay as a monotypic species, with a general range of "...from central Washing- ton, Idaho, and central Montana south to northern lower California." Mayr and Greenway (1962) also consider this species monotypic. AOU (1957) considers the Pinon Jay a monotypic member of the avian order Passeriformes, family Corvidae, subfamily Corvinae. Mayr and Short (1970) state that the relationships of this species remain obscure; no further comment given. Austin and Rea (1976) do not advocate recognition of races in the Pinon Jay. Ligon (1974) summarizes the taxonomic relationships of Gymnorhinus in a detailed manner; states that this species should be considered a "specialized and perhaps early offshoot of... New World jays. ' Miller and Stebbins (1964) feel that the Pinon Jay in Joshua Tree National Monument should be considered a distinct race, Gymnorhinus cyomocephalus ro stratus. C. Synonomies of scientific nomenclature Hellmayr (1934), Cyanocephalus cyanocephalus ; C. wiedi; Cyanocorax wiedi. Gnnnell and Miller (1944; , Gymnokitta cyanocephala ; Gymnorhinus cyanocephalus ro stratus. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Maximilian Jay. Ligon (1961), Blue Crow. Goodwin (1976) adds Pinon Crow to the previous names. Dawson (1923) includes Pine Jay in his list of synonomies. Also called the nutcracker by Wheelock (1904), II DESCRIPTION A. External morphology of adults Ridgway (1904) gives detailed account of all plumages; "adult male... dull grayish blue, paler on posterior under Gymnorhinus cyanocephalus (con't.) parts. . .adult female similar." In appearance and actions like a small dull blue crow. ..with a long sharp bill (Peter- son 1961). Phillips et al. (1964), "the Pinon Jay looks like a small blue crow, and like it, walks rather than hops." Ligon (1961), 10-11.5 inches long. Ligon and White (1974) give detailed account of plumage and size characteristics; the crown in adults is deep blue... color change due to wear occurs. B. External morphology of subadult age classes Ridgway (1904) noted young were duller than the adult female, without any blue except on wings and tail... plain gray. Bailey (1928) gives similar description. Goodwin (1976), "first year plumage. . .grey, the adult blue plumage not be attained till the second summer molt." Juvenile body feathers are gray with no hint of blue... the whitish throat patch of first-year and adult birds is lacking; mouth color is white (Ligon and White 1974). C. Distinguishing characteristics Interspecific - "Easily told from Scrub Jay by its short tail, uniform blue coloration, and crowlike flight; from Steller's Jay by lack of crest (Peterson 1961). Robbins et al. (1966): told from other jays by its uniform steel- blue color, short tail, and long beak. ' Intraspecific - Ridgway (1904) states that although sexes are similar in coloration, the female is smaller and duller than the male; young are similar to adult female, but still duller. Male: wing 154 mm, length 272.5 mm, tail 114 mm and female: wing 144.5 mm, length 254.5 mm, tail 104 mm. Color pattern of sexes alike (Ligon 1961). Dawson (1923), "adult female like male... with increase of gray." Adult male Pinon Jays are significantly larger than adult females, according to results of a detailed study by Ligon and White (1974). Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) gives distribution of G. cyanocephalus as, "Resident from central Oregon, east-central Montana, and western South Dakota, south through eastern California to northern Baja California, central Nevada, central and central eastern Arizona, central New Mexico, and western Oklahoma Ridgway (1904) gives range as, "Pinyon and juniper wood- lands of western United States; north to southern British * • Gymnorhinus cyanocephalus (con't.) Columbia, Idaho, ect. , south to northern lower California, Arizona, New Mexico, and western Texas; east to eastern side of Rocky Mtns." Peterson (1961): "Resident from Oregon, Idaho, Montana. .. through eastern California (east of Sierra) to northern Baja California, Nevada, Arizona, New Mexico, Oklahoma. " B. California distribution of the species Grinnell and Miller (1944), "... resident. . .parts of elevated Great Basin area, west to east base of Cascade- Sierra Nevada ...south along this system to vicinity of Walker Pass, Kern Co. ; also south along all higher desert ranges as far as Providence Mtns., San Bernardino Co." Small (1974) called California distribution "complex"; Basin and Range Region south to Walker Pass; south along higher desert ranges to Providence Mtns. ; north side of San Gabriel and San Bernardino Mtns.; Mt. San Jacinto area, near Lake Hemet, Riverside Co. Dawson (1923), "common resident locally of arid upper Sonoran and Transition, chiefly along the eastern base of the Sierra Nevada." In southern California, this jay is a resident, locally, of upper Sonoran and Transition Zones, mostly on the desert side of mountain ranges, south to Baja California (Willett 1933) Wheelock (1904) describes the California breeding range as, "in the pinyon belts of the desert ranges, southeast of the Sierra Nevada. .. locally the whole length of the Sierra Nevada... to the San Bernardino Mountains." Jordan (1956) reported that the occurrence of this species on the western slope of the central Sierra Nevada was a rare sighting in the fall. Wall (1915) stated that Pinon Jays seldom occur in the San Bernardino Valley; a sighting in October (1914) was the first in 25 years. C. California desert distribution Desert locations given by Grinnell and Miller (1944) include - White, Inyo, Grapevine, Panamint, Argus and Co so Mountains in Mono and Inyo Counties; San Bernardino and San Jacinto Mountains. Dawson (1923) noted this species on the desert mountain ranges of the Inyo district. Johnson et al. (1948) found Pinon Jays to be widespread near the New York and the Providence Mountains in both summer and winter; frequented pinyon and juniper woodlands. Grinnell and Swarth (1913) noted large flocks near Kenworthy and Hemet Lake between June and August. Willett (1933), in describing the southern California distribution — "noted in San Bernardino Mtns. ; found abundant in Hemet Valley, San Jacinto Mtns. (summer); also noted in Pasadena; nests on the deserts slopes of the San Jacinto range." Noted in the desert ranges of the Inyo district by Grinnell (1915). Willett (1951) only noted the bird as a straggler out onto the desert in winter (from nearby desert ranges). Wauer (1964) found Pinon Jays nest- ing in the pinyon- juniper woodlands of the Panamint Mountains, Gymnorhinus cyanocephalus (con't.) Death Valley. Gullion et al. (1959) noted the erratic occurrence of Pinon Jays on southern Nevada deserts (Joshua tree, oak chaparral) during all seasons. Several birds found wintering near ponds in Death Valley by Gilman (1936). D. Seasonal variations in distribution Robbins et al. (1966) --"in winter, it wanders erratically to farmlands." Wanderings. .. seem to be influenced by lack of a dependable source of food. .. rather than by set, seasonal migratory movements (Ligon 1961)." Johnson et al. (1948) noted movement down into Joshua trees during winter in the Providence Mtns. In Nevada, this jay is a common fall and winter visitor to the pinyon- juniper belt, and in the fall is noted in the pines up to 8,700 ft. by Rossem (1936). "But the species is disposed to undertake wanderings, when flocks appear sporadically in remote places irrespective of season' (Grinnell 1915). Called an "irregular visitant" in Los Angeles Co., mostly in the higher mountains — will descend into the foothills in fall and winter (Grinnell 1898). Bent (1946) states that the species is not really migratory, but undertakes seasonal wanderings depending upon local conditions. Miller (1915) describes the winter movements of this species as erratic; noted a flock in Los Angeles from December to March, 1914-15. IV HABITAT A. Biotopic affinities Peterson (1961) describes habitat as, "pinyon pines, juni- pers; ranges into sage." Grinnell and Miller (1944), essentially characterized by presence of pinyon and juni- per." Small (1974), "pinyon- juniper woodland; lower por- tions of montane forest in Transition Life Zone." Phillips et al. (1964) describes this jay as characteristic of pinyon and juniper woodlands, though they often wander into the pine belt. Goodwin (1976) states that the species inhabits the foothills and lower mountain ranges where pinyon and juniper are the dominant vegetation. Grinnell and Swarth (1913) found jays foraging in sagebrush during June in Hemet Valley. In Joshua Tree National Monument, Miller and Stebbins (1964) found Pinon Jays confined to the pinyon- juniper belt of the upper levels of the western section. They did not see them in lower desert vegetation. B. Altitudinal range Grinnell and Miller (1944) note breeding range from 4,500 ft. (San Jacinto Mtns.) up to 7,500 ft. (Inyo Mtns.). Ligon (1961) gives 5,500 to 7,400 ft. range in New Mexico. Dawson (1923) gives an upper range of 9,000 feet in California. 4l Gymnorhinus cyanocephalus (con't.) Pinon Jays noted between 5,000 and 8,200 ft. in Nevada (Lindsdale 1936). Ligon (1971) reported this species nesting in mature pinyon pines at 7,200 ft. in New Mexico. Found breeding in a Joshua Tree and juniper woodland at 4,800 ft. at Joshua Tree National Monument by Miller and Stebbins (1964). Noted breeding between 5,500 and 6,500 ft. in the Panamint Mountains, Death Valley (Wauer 1964). C. Home range size Balda et al. (1972) studied a flock of about 250 Pinon Jays on a home range of 8 square miles near Flagstaff, A izona. D. Territory requirements Perch sites - Roost sites in Arizona ranged from 3-16 m above ground with a mean height of 7.4 m; all roosts were in ponderosa pine (Balda et al. 1977). Courtship and mating sites - Balda and Bateman (1972) des- cribes courtship and mating sites in detail. The first stages of courtship take place on the ground, but as the nesting season approached, trees were used more often. Pairs select a branch or crotch of a tree on the breeding ground where courtship reaches its height of activity. Nest sites - "A bowl of twigs in pinyon, juniper, scrub oak; in colony (Peterson 1961). Bailey (l928), "nests in colonies, in pinyon pines, junipers, or oaks, generally 5 to 12 feet from ground." Ligon (1961) reported nests, one per tree, in 10 to 15 feet oaks. Dawson (1923), "placed at moderate height in pinyon or juniper." A nest in the Joshua Tree National Monument was 7 ft. up in a juniper (Miller and Stebbins 1964). Bent (1946) reports nests in juniper from 3 to 18 ft. high, with nests in ponderosa pine up to 85 ft. (Oregon). Johnson (1902) gives nest sites as pinyon pine, scrub pine, juniper, and mountain mahogany. Balda and Bateman (1972) found nests that ranged from 5.5 to 78 ft. high in a ponderosa pine forest in Arizona. V FOOD A. Food preferences Grinnell and Miller (1944) call this species omnivorous, supplimenting their pinyon seed diet with insects. Bailey (1928), "principally pinyon nuts in their season, but also yellow pine and black pine nuts, cedar and juniper berries, small seeds, various wild berries, and insects. ' Dawson (1923) gives favorite food as pinyon nuts; berries also taken. Food given to nestlings in New Mexico included numerous insect larvae and nymphs, several adult beetles, Gymnorhinus cyanocephalus (con't.) a lizard, but few pine seeds (Ligon 1971). Animal food includes beetles, grasshoppers, caterpillars, and ants; pine seeds, especially pinyon pine, wheat, cedar, and corn constitute the main plant foods taken (Martin et al. 1951). Bateman and Balda (1973) give a detailed account of food habits (Arizona) ; terrestrial insects formed the major part of the diet during the breeding season. B. Foraging areas Robbins et al. (1966): "is often seen on ground around sagebrush." Johnson et al. (1948) noted a flock of jay foraging on the ground through junipers and pinyons on a sagebrush flat in the Providence Mtns. When settled into an area to feed, a flock of about 250 birds occupied an area of about 2 acres during the morning and evening, and up to 6 acres during the afternoon when feeding was not so intense; the flock spent about 80% of its time in pine forest and 10% in open meadow and woodland (Balda and Bateman 1971). Bateman and Balda (1973) noted that most food for nestlings was gathered by adult males, who foraged together in small flocks (6-8 birds) in open parts of the ponderosa pine forest in northern Arizona. C. Foraging strategies Bailey (1928), "in feeding. .. their method of spreading out and working zigzag over the ground in search of insects... large flocks. .. engage in catching insects on the wing." Were also noted both picking seeds from the ground and extracting them from cones. Wheelock (1904) noted the taking of insects "on the wing." When feeding in forest and wood- land, about 40% of the flock foraged on the ground by prob- ing for insects and/or pine seeds. Pinon Jays often cache seeds; at 21 cache-sites the number of seeds varied from 6 to 31 (Balda and Bateman 1971). Foraging flocks, "moved along in a rolling fashion, the members at the rear flying over and past those ahead of them on the ground" (Miller and Stebbins 1964). D. Feeding Phenology Dawson (1923), "in summer they feed largely on insects of all kinds, especially grasshoppers." The only plant food taken in great amounts during spring are pinyon pine seeds; other grains are also taken in winter when insects cannot be found (Martin et al. 1951). Balda and Bateman (1972) found that Pinon Jays harvest and cache seeds of both pon- derosa and pinyon pines in the fall and early winter. Gymnorhinus cyanocephalos (con't.) E. Energy requirements Balda and Bateman (1976) recount the eating of nestlings by adult Pinon Jays; they felt that such actions were a result of a severe energy drain on the adults due to cold (-17°C to 1°C) temperatures and a heavy snow cover. Ligon (1974) states that nestling Pinon Jays cannot survive on a diet composed exclusively of pinyon seeds. Pinon Jays often eat snow, which at times is their only source of free water, according to Balda and Bateman (1971). They also stated that this jay relies heavily on pinyon seeds for reproductive energy. Balda et al. (1977) found that roost sites were selected, in part, for thermal economy; birds roosted within a trees foliage in a south (sun) facing direction. VI REPRODUCTION A. Age at first breeding Goodwin (1976), "first-year birds do not usually breed." B. Territorial behavior • "Often in large noisy flocks; gregarious" (Peterson 1961). Ligon (1961), "the birds' social instinct is clearly re- flected in colony nesting;" two colonies of 50 nests each and one of 13 nests reported. During breeding, the adult male performs most territorial defense; the female does not leave the nest to attack predators (Balda and Bateman 1974). C. Courtship and mating behavior "The male usually initiates nest site selection, enticing his mate to the site by carrying sticks to it and feeding her. . .both sexes bring nest lining material to the site for 3 to 5 days before serious building starts (Goodwin 1976)." Feeding of potential mates is low in October but shows a marked increase in November and December; courtship occurred most often from mid-morning to mid-afternoon (Balda and Bateman 1971). Balda and Bateman (1972) give a detailed account of courtship behavior, which include silent food transfer, courtship begging, silent sitting, stick mani- pulation, and display flights. D. Nesting phenology Bailey (1928) gives nesting season as from February to June. Reed (1904) noted nesting during April or May. Ligon (1961) reports fresh eggs from February to October. Dawson (1923) --season, April to May 10; one brood. "Probably nests mostly Gymnorhinus cyanocephalus (con't.) in late March and early April in southern California" (Willett 1933). Wheelock (1904) gives California breed- ing season as March 15 to May 15. Pairs not successful in their first nesting attempt form a second nesting colony ...pairs failing in the second nesting attempt may try a third time (Balda and Bateman 1971). By late December some male jays are in breeding condition; if conditions are suitable, the birds may breed in early February, al- though breeding may be delayed several months if food is scarce (Ligon 1971; . Bent (1946) gives California egg dates as April 9 to 21. E. Length of incubation period Goodwin (1976) gives 16 day incubation, which is performed only by the female. Wheelock (1904) gives a 16 day incu- bation period. Ligon (1971) reported a 17 day incubation period in New Mexico. Bent (1946) listed the period as 16 to 18 days. Bateman and Balda (1973) found a 17 day period in northern Arizona. F. Length of nestling period "The young fledge at about 3 weeks (Goodwin 1976)." Wheelock (1904) states that the young fledge in about 22 days. Nestling period of about 20 days in New Mexico at 7,200 ft. (Ligon 1971). In northern Arizona, Bateman and Balda (1973) found Pinon Jay young fledging at 21-22 days of age. G. Growth rates Bateman and Balda (1973) give a detailed description of growth rates- -"At 10 days of age young Pinon Jays averaged 9.2 times as heavy as on the day of hatching (6.26 g versus 78.00 g) . During the latter half of the nestling period (days 11-21) increase in weight was greatly reduced while plumage growth was pronounced. H. Post-breeding behavior Young unite with other families in large flocks after fledg- ing, and forage from place to place with the roving habits of their species (Wheelock 1904). Upon leaving the nest, young and parents form tightly knit feeding aggregates that remain near the nests for 8-12 days; by late April, these feeding groups increased in size and consisted of 25-50 young and adults (Balda and Bateman 1971). Richards (1924) noted the wintering behavior of a large flock in northern California which, divided into three or four flocks, which were much in evidence. .. (until) the first of April, when the birds began to leave." At 4 weeks of age, Bateman and Balda (1973) found that young jays were still fed by their parents. After 8 weeks of age young were able to fly well and feed themselves; they joined their parents flock. # • • Gymnorhinus cyanocephalus (con't.) II POPULATION PARAMETERS A. Clutch size Peterson (1961) - Eggs (3-4; 5). speckled. Bailey (1928) - eggs usually 4-5. Read (1904) gave clutch of 3-5 eggs. Ligon (1961), "eggs usually 4, rarely 5." Dawson (1923) lists usual clutch as 4 or 5. Bent (1946) gives the highest clutch as 6 eggs. Balda and Bateman (1972) gave an average clutch as nearly 4 eggs. B. Fledging success In New Mexico, Ligon (1971) reported only 4 of 13 nests successful; these 4 nests produced a maximum of 13 young. He felt that such low nest success may be usual for the species. Balda and Bateman (1972) found that nest success was dependent upon placement within the colony. Nests near the center of the colony lost fewer eggs than those towards the edge. Overall nest success was highly variable, and ranged between 17 and 50%. C. Mortality rates per age class Ligon (1961) reports a large number of nestlings dead in the nest after cold rains. Balda and Bateman (1972) found that early nesting attempts often failed (80% nest destruc- tion in one year) due to severe weather conditions. Pre- dators took 41-68% of all nests in their study. D. Longevity Pinon Jays may have a life expectancy of 6 years or more, based on band returns (Whitney 1963) . E. Seasonal abundance Pinon Jays are seen most often in flocks, even in the nest- ing season. Flocks are much larger in winter than in summer (Linsdale 1936). Jensen (1926), "...it is not unusual, during fall and winter, to see flocks of hundreds..." F. Habitat density figures Johnson et al. (1948) noted flocks of up to 400 jays during summer and winter in the Providence Mtns. Grinnell (1908) found flocks of about 100 birds on the arid slopes of the San Bernardino Mtns. A colony of at least 100 nests was found in a pinyon- juniper woodland in Nevada (Lindsdale 1936). A flock of 75 birds in March near San Onofre, San Diego Co., is a rare spring record for this area (Willett 1933). Balda and Bateman (1971) located 6 Pinon Jay flocks 10 Gymnorhinus cyanocephalus (con't.) within a 15-mile radius of Flagstaff, Arizona, an area dominated by ponderosa pine, pinyon pine, and juniper. A flock of about 50 birds spread their nests about within a few hundred yards of each other in a Joshua Tree-juniper woodland (Joshua Tree Nat. Monument) (Miller and Stebbins 1964). They noted groups of 125 to 175 birds in October, with groups of 50 to 100 seen in late summer and fall. Gabrielson (1949) saw an unusually large flock of "several thousand birds" during the winter in Nevada. Jensen (1923) studied a colony in northern New Mexico which contained 17 nests covering about 10 acres. Balda and Bateman (1972) found that a flock of 250 jays in Arizona used an area covering 240 acres for nesting, although their total home range covered 8 square miles. In each year of their study the colony averaged one nest per 2.3 acres. IIII INTERSPECIFIC INTERACTIONS A. Predation Potential predators of all age classes, including eggs and young, in New Mexico listed as Bobcat, Cooper's Hawk, Barn Owl, Great Horned Owl, and Scrub Jay (Ligon 1971). Bent (1946) recounts the taking of nestlings by a pair of North- ern Shrikes. Bond (1940) reported finding Pinon Jay feathers in a Nevada Goshawk nest. Enderson and Craig (1974; noted Peregrine Falcon attacks upon Pinon Jays in the Rocky Mountains. Balda et al. (1972) describe the anti-predator behavior of Pinon Jays, which was directed against Sharp- skinned, Cooper's Red-tailed, and Rough-legged hawks, and Great Horned Owls in Arizona. B. Competition Pinon Jays and Starlings found together in Colorado by Beidleman and Enderson (1964); no further comment given. C. Parasitism Friedmann (1963) does not list the Pinon Jay as a victim of cowbird parasitism. IX STATUS A. Past population trends Called a "common" resident by Grinnell (1915). B. Present population status Grinnell and Miller (1944), "resident within state. . irregular, local shif tings of population. Because they are gregarious. . . 11 Gymnorhirius cyanocephalus (con't.) usually considered common or even abundant." Small (1974), "resident, but populations move. . .depending upon local food conditions and weather." Called a "locally common, permanent resident," in Joshua Tree National Monument (Miller and Stebbins 1964). C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status 12 Gymnorhinus cyanocephalus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Austin, G. T. and A. M. Rea. 1976. Recent southern Nevada bird records. Condor 78:405-408. Bailey, F. M. 1928. Birds of New Mexico. New Mexico Dept. Game and Fish. 807 pp. Balda, R. P. and G. C. Bateman. 1971. Flocking and annual cycle of the Pinon Jay, Gymnorhinus cyanocephalus . Condor 73:287-302. Balda, R. P. and G. C. Bateman. 1972. The breeding biology of the Pinon Jay. Living Bird 11:5-42. Balda, R. P. and G. C. Bateman. 1973. Unusual mobbing behavior by incubating Pinon Jays. Condor 75:251-252. Balda, R. P. and G. C. Bateman. 1976. Cannibalism in the Pinon Jay. Condor 78:562-564. Balda, R. P., G. C. Bateman and G. F. Foster. 1972. Flocking associates of the Pinon Jay. Wilson Bull. 84:60-76. Balda, R. P., M. L. Morrison, T. R. Bement. 1977. Roosting behavior of the Pinon Jay in autumn and winter. Auk 94: 494-504. Bateman, G. C. and R. P. Balda. 1973. Growth, development and food habits of young Pinon Jays. Auk 90:39-61. Beidleman, R. G. and J. H. Enderson. 1964. Star ling -Pinon Jay associations in southern Colorado. Condor 66:437. Bent, A. C. 1946. Life histories of North American jays, crows and titmice. Part 2. U.S. Nat. Mus. Bull. 191: 215-495. Bond, R. M. 1940. A Goshawk nest in the Upper Sonoran life- zone. Condor 42:100-103. Braly, J. C. 1931. Nesting of the Pinon Jay in Oregon. Condor 33:29. Cannon, F. D. 1973. Nesting energetics of the Pinon Jay. Unpubl. M.S. thesis, Northern Arizona Univ., Flagstaff. 4 ^ 13 Gymnorhinus cyanocephalus (con't.) Dawson, W. L. 1923. The birds of California. Vol. 1. South Moulton Co., San Francisco. Enderson, J. H. and J. Craig. 1974. Status of the Peregrine Falcon in the Rocky Mountains in 1973. Auk 91:727-736. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233. 276 pp. Gabrielson, I. N. 1949. Bird notes from Nevada. Condor 51: 179-187. Gilman, M. F. 1936. Additional bird records from Death Valley. Condor 38:40-41. Goodwin, D. 1976. Crows of the world. Cornell Univ. Press, Ithaca, New York. 354 pp. Grinnell, J. 1898. Birds of the Pacific slope of Los Angeles County. Pasadena Academy Sci. No. 11:1-52. Grinnell, J. 1908. The biota of the San Bernardino Mountains. Univ. California Publ. Zool. 5:1-170. Grinnell, J. 1915. A distributional list of the birds of California. Pacific Coast Avifauna No. 11. 217 pp. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp. Grinnell, J. and H. S. Swarth. 1913. An account of the birds and mammals of the San Jacinto area of southern California. Univ. California Publ. Zool. 10:197-406. Gullion, G. W. , W. M. Pulich and F. G. Evenden. 1959. Notes on the occurrence of birds in southern Nevada. Condor 61: 278-297. Hellmayr, C. E. 1934. Catalogue of birds of the Americas. Part 7. Field Mus. Nat. Hist. Zool. Ser. Publ. 330, Vol. 13. Henderson, J. 1920. Migrations of the Pinyon Jay in Colorado. Condor 22:36. Jensen, J. K. 1923. Notes on the nesting birds of northern Santa Fe County, New Mexico. Auk 40:452-469. Jensen, J. K. 1926. The Pirion Jay. Oologists1 Record 6:41- 43. 14 Gymnorhinus cyanocephalus (con't.) Johnson, H. C. 1902. The Pinyon Jay. Condor 4:14. Johnson, D. H. , M. D. Bryant and A. H. Miller. 1948. Verte- brate animals of the Providence Mountains area of California. Univ. California Publ. Zool. 48:221-376. Jordon, P. A. 1956. Pinon Jays west of thp Sierra Nevadan divide in California. Condor 58:238. Ligon, J. S. 1961. New Mexico birds. Univ. New Mexico Press, Albuquerque. 360 pp. Ligon, J. D. 1971. Late summer- autumnal breeding of the Pinon Jay in New Mexico. Condor 73:147-153. Ligon, J. D. 1974. Comments on the systematic relationships of the Pirion Jay (Gymnorhinus cyanocephalus) . Condor 76: 468-470. Ligon, J. D. and J. L. White. 1974. Molt and its timing in the Pinon Jay. Condor 76:274-287. Linsdale, J. M. 1936. The birds of Nevada. Pacific Coast Avifauna No. 23. 145 pp. Martin, A. C. , H. S. Zim and A. L. Nelson. 1951. American wildlife and plants. McGraw-Hill Book Co., New York. 500 pp. Mayr, E. and J. C. Greenway, Jr. Editors. 1962. Checklist of birds of the world. Vol. 15. Mus. Comp. Zool., Cam- bridge, Mass. 315 pp. Mayr, E. and L. L. Short. 1970. Species taxa of North American birds. Publ. Nuttall Ornithol. Club 9:1-127. Miller, L. H. 1915. Pinyon Jays in Los Angeles. Condor 17: 166. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. Calif- ornia Press, Berkeley. 452 pp. Peterson, R. T. 1961. A field guide to western birds. 2nd Edition. Houghton Mifflin Co., Boston. 366 pp. Phillips, A., J. Marshall, and G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. 212 pp. Reed, C. A. 1904. North American birds eggs. Doubleday, Page & Co., New York. 356 pp. (f « 4 15 Gymnorhinus cyanocephalus (con't.) Richards, E. B. 1924. A list of the land birds of the Grass Valley District, California. Condor 26:98-104. Ridgway, R. 1904. The birds of North and Middle America. Part 3. Bull. U.S. Nat. Mus. No. 50. Robbins, C. S., B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Selander, R. K. 1956. Additional record of the Pinon Jay in Mexico. Condor 58:239. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Van Rossem, A. J. 1936. Birds of the Charleston Mountains, Nevada. Pacific Coast Avifauna No. 24. 65 pp. Wall, E. 1915. Notes from San Bernardino, California. Condor 17:59. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Westcott, P. W. 1964. Invasion of Clark Nutcrackers and Pinon Jays into southeastern Arizona. Condor 66:441. Wheelock, I. G. 1904. Birds of California. A. C. McClurg and Co., Chicago. 578 pp. Whitney, M. R. 1963. Results of Pinyon Jay banding in South Dakota. Bird-Banding 34:219. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles Co. Mus. Zool. Ser. 6:1-39.

< « Parus inomatus (con't.) 711 POPULATION PARAMETERS A. Clutch size Price (1936), average for 62 sets found to be 6.75 eggs; range 3 to 9. Dixon (1949), "variable." B. Fledging success Dixon (1949) "Eight birds of the 24 fledged survived." This involved seven breeding pairs. G. Mortality rates per age class Dixon (1949), Adults: "survival of five of the twelve adults from the 1947 breeding season is only 41.6 per cent of that total." Young: "Eight birds of the 24 fledged survived... death rate of 66 per cent among young birds fledged." D. Longevity Dixon (1949) of 22 breeding individuals, one each were 5 and 6 years, three were 4 years, seven were 3 years, six were two years, and four were one year. "Average life expectancy of an established adult appears to be about three years." Price (1936) "The oldest titmouse recorded. . .banded as adult in 1928 and was recaptured in the same box in 1934 when it must have been at least seven years old." E. Seasonal abundance Hardy (1945) "found in a family group of a half dozen or so for a short time in the period after the young leave the nest." F. Habitat density figures Dixon (1949) "The breeding population of the study area [.144 acres] was stabilized at a density of seven pairs." Gaines (1974), reports from 26 to 66 territorial males per square kilometers; 26, 43, and 30 per km^ in clumped cotton- wood and willow woodland; 68 and 66 per km^ in riparian oak woodland. VIII INTERSPECIFIC INTERACTIONS A. Predation Price (1936), "Jays [ Aphelocoma californicaj are often seen about the nesting Doxes containing young titmouses and sometimes perch on the box and peer inside. When young birds leave the nest the jays often dive at them and kill them." 10 Parus inomatus (con't.) B. Competition Davis, Fisher, and Davis (1963), noted that 3 of 44 attacks by two territorial pairs of western Flycatchers were dir- ected at P. inomatus . Dixon (1954), detailed discussion of interactions between Chestnut-backed Chickadees and Plain Titmice. "Study of foraging habits suggests only partial overlap in foraging sites in winter. During the period when fledglings were being fed, size of food items taken appeared to differ." C. Parasitism IX STATUS A. Past population trends Grinnell and Miller (1944), P. i. zaleptus: "Resident. Distribution much interrupted and population usually sparse." P. i. ridgwayi : "Resident. Under optimal conditions of KabTtat, common." P. i. kernensis; "Resident. Where most favorable habitat conditions prevail, common." P. i. transpositus: "Resident. Common, even abundant locally." B. Present population status Small (1974), "common resident." C. Population limiting factors D. Environmental quality: adverse impacts Grinnell and Miller (1944), "Retraction of range has taken place locally, where oaks have been felled to clear for agriculture; on the other hand, tree-planting, even in sub- urbs of towns, has brought favoring conditions in previously unoccupied neighborhoods." E. Potential for endangered status « 11 Parus inornatus (con't) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bent, A. C. 1946. Life histories of North American jays, crows, and titmice. U.S. Nat. Mus. Bull. No. 191. Davis, J., G. F. Fisler and B. S. Davis. 1963. The breeding biology of the Western Flycatcher. Condor 65:337-382. Davis, S., B. S. Davis and J. Davis. 1973. Some factors affecting foraging behavior of Plain Titmouse. Condor 75:481-482. Dawson, W. L. 1923. The birds of California. South Moulton Co., San Francisco. Dixon, K. L. 1949. Behavior of the Plain Titmouse. Condor 51:110-136. Dixon, K. L. 1954. Some ecological relations of chickadees and titmice in central California. Condor 56:113-124. Dixon, K. L. 1961. IN Vertebrate Speciation Blair, W. F. (Ed.) pp. 179-216. Univ. Texas Press, Austin. Dixon, K. L. 1962. Notes on the molt schedule of the Plain Titmouse. Condor 64:134-139. Dixon, K. L. 1969. Patterns of singing in a population of the Plain Titmouse. Condor 71:94-101. Gaines, D. 1974. A new look at the nesting riparian avifauna of the Sacramento Valley, California. Western Birds 5(3): 61-79. Grinnell, J. and W. H. Behle. 1937. A new race of titmouse, from the Kern Basin of California. Condor 39:225-226. Grinnell, J. and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. Hardy, R. 1945. Breeding birds of the pigmy conifers in the Book Cliff region of eastern Utah. Auk 62:523-542. Jordan, D. S. 1925. California Tufted Titmouse feeds on sun- flower seeds. Condor 27:241. Miller, A. H. 1946. Endemic birds of the Little San Bernar- dino Mountains, California. Condor 48:75-79. 12 Parus inornatus (con't.) Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. Vol. 50, No. 6. Peters, J. L. 1967. Checklist of the birds of the world. Vol. 12. (D. Snow, ed. ) Mus. Comp. Zool., Cambridge, Mass- achusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co. , Boston. Price, J. B. 1936. The family relations of the Plain Titmouse. Condor 38:23-28. Small, A. 1974. The birds of California. Macmillan Co., New York. Ridgway, R. 1904. The birds of North and Middle America. Part III. Bull. U.S. Nat. Mus. No. 50. t* t POOR WILL Phalaenoptilus nuttallii I TAXONOMY A. Type description AOU (1957), P. n. nuttallii: Caprimulgus nuttallii, Audubon, Bds. Am. octavo ed. , 7, 1844, p. 350, pi. 495. P. n. hueyi : P. n. hueyi , Dickey, Condor, 30, 1928, p. 152. TBard, Imperial County, California. ) B. Current systematic treatments Peters (1940) monospecific genus with four subspecies: P. n. nuttallii; P. n. calif ornicus; P. n. hueyi ; P. n. Hicfceyi. CaprimulgiTormes: Caprimulgidae. C. Synonomies of scientific nomenclature Peters, J. L. , 1940, Checklist of Birds of the World, Vol. 4, p. 193, Mass.: Harvard U. Press Caprimulgus nuttallii (Audubon). Grinnell and Miller (1944), P. n. nuttallii: Ant ro stomas nuttallii ; P. nuttallii nyctophTlus. P_. n. hueyi: P. nuttallii nitTdus. D. Synonomies of vernacular nomenclature Dawson (1923), Nut tail's Poorwill. Grinnell and Miller (1944), P. n. nuttallii: Nuttall Poor-will; Nuttall Whip- poor-will; Frosted Poor-will. P. n. hueyi : Frosted Poor- will; Huey Poor-will. II DESCRIPTION A. External morphology of adults Peterson (1961), "rounded wings (no white bar). Its short rounded tail has white corners." Ridgway (1914), detailed description of adults including plumage, soft parts, and measurements. Dawson (1923), Adult: a central patch of pure silky white across lower throat; below this, in abrupt contrast, a band of black. .. the three outer pairs of tail feathers tipped broadly but decreasingly with white or buffy whites; remaining plumage. . .black centers of feathers with buffy intermingled dusky marginings." Selander (1954), "do not show pronounced color phases." • Phalaenop ti lus nuttallii (con't.) / ~jr B. External morphology of subadult age classes Ridgway (1914), "Young — not essentially different from adults, but markings in general less sharply defined, especially on underparts, and throat patch buff instead of white. Downy young--Downy covering vinaceous-buf f , paler on underparts, feathers appearing on upper parts dull buffy white minutely stippled and vermiculated with grayish and with small spots and narrow bars of black; those on middle underparts dull white barred, more or less distinctly, with grayish or dusky. C. Distinguishing characteristics Interspecific - Peterson (1961), "smaller than a nighthawk, has more rounded wings (no white bar) .„. short rounded tail with white corners." Intraspecific - Dawson (1923), "P. n. nuttallii paler than calif ornicus ; darker than nitidus. " Grinnell (1928), P. n. hueyi , "nearest in color to the light type of P. n. nuttaTlii ..., but averaging very much lighter. Backs... are a pinkish tan, almost devoid of the silver frosting. .. the size of the dark dorsal "owl's eye" marking greatly reduced, in many cases practically obsolete." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957): "From southern interior British Columbia, south- eastern Montana, northwestern South Dakota, Nebraska, and southwestern Iowa south on the Pacific coast from central California to southern Baja California and through eastern Kansas and central Texas to central Mexico (Guanajuato). Winters from central California, southern Arizona, and southern Texas southward." P. n. nuttallii: Breeds from southern interior British CoTumBia (Clinton) , southern Alberta, southern Montana (Valley, Gallatin, Fergus, and Prairie counties), northwestern South Dakota (Slim Buttes), and Nebraska south through eastern Washington, eastern Oregon, and eastern California (east of the Cascade Moun- tains and the Sierra Nevada) to the Mohave Desert, central and southeastern Arizona, Sonora, Coahuila (Saltillo), east to eastern Kansas (Lawrence), northwestern Oklahoma (Woods and Cimarron counties), and southern Texas (San Antonio); casual in Southwestern Iowa (Pottawattamie County)." P. n. hueyi : "Breeds in valley of lower Colorado River in south- eastern California, southwestern Arizona, northeastern Baja California, and extreme northwestern Sonora." ^ Phalaenop ti lus nuttallii (con't.) B. California distribution of the species Small (1974), "length of state except humid northwestern portion and Central Valley." Dawson (1923), "summer resi- dent of Upper Sonoran and Transition areas east of the Sierras, from Death Valley northward, and through the northern counties west at least to Yreka, Siskiyow County." C. California desert distribution Jaeger (1949), "Chuckawalla Mountains of the Colorado Desert, California." Cardiff (1956), reported on two occasions near Westmoreland. Carter (1937), heard fre- quently at night during April and May; often seen in Oct- ober— Twentynine Palms, San Bernardino County. Abbott (1940), reports nest of P. n. hueyi in May, 1940, at eastern end of Salton Sea. Bickroro" ( 1929) , reported as resident in Napa County. Gilman (1935), reported in Death Valley in November. One dead found in January. Bent (1940) "San Diego, Escondido, Ojai Valley." Miller (1951) Modec, Inyo, Shasta Valley, Mojave (P. n. nuttallii) Colorado Desert (P. n. hueyi) . Grinnell and Miller (1944), P. n. nuttallii: WHite, Inyo, Grapevine, Funeral, Panamint, and Argas Moun- tains; Cosa Valley, Death Valley (Inyo County). Mission gk Valley, San Diego County. Colorado River Valley, Riverside ^f Mountain, Riverside County, to near Picacho, Imperial County. P. n. hueyi : "Valley of Colorado River, from Needles, San Bernardino County, at least to Bard, Imperial County. . . Imperial Valley, as at eastern end of Salton Sean. .. Inter- grades with P. n. nuttallii occur in Providence Mountains, area, San Bernardino County." D. Seasonal variations in distribution AOU (1950) P. n. nuttallii: "Winters from eastern California (Death Valley), southern Arizona (Tucson), and southern Texas (El Paso, Kerrville) south to Sonora (Tiburon Island), Guanajuato, and Coahuila." Small (1974), "primarily a sum- mer visitor (California), April to November in the northern half of the state; some may overwinter by hibernating." Dawson (1928), "Winters in the southern portion of its range and irregularly southward over the deserts and in the valley of the Colorado." Culbertson (1946), discusses reports of individuals presumably in torpor, including own sighting in Fresno County in February. "It is well to note that none of the winter records of the occurrence of the Poor-will in the Sierran foothills are of birds in f light. .. flushed in the daytime or found in an inactive state." • '• Phalaenoptilus nuttallii (con't.) IV HABITAT A. Biotopic affinities Peterson (1961), "Stony arid hills, open pinon- juniper, sparse brush." Small (1974), "Chaparral, pinon- juniper woodland, brushy slopes, desert washes and desert floor with scattered bushes." Orr (1948) "high transition forest ...composed principally of Jeffrey pine (Pinus ponderosa var. jef freyi) , sugar pine ( Pinus lambertiana) and white fir (Abies concolor) . ♦ .a rocky knoll strewn with large granite boulders. . .huckleberry oak (Que reus vaccinifolia) ...clumps of brush, consisting of tobacco brush (Ceanothus yelutinus) , green manzanita (Arctostaphylos patala) and bush chinquapin (Castanopsis semipervirensT. Bendire (1895) "open prairie. . .almost barren and arid regions of the interior, which are covered only here and there with stunted patches of sage (Artemisia) and other desert plants. The climate does not seem to affect it much, as it inhabits some of the hottest regions of the continent, like Death Valley, in southern California, as well as the slopes of the Rocky and Blue Mountains in Oregon, where it reaches alti- tude of from 6,000 to 8,000 feet." Miller (1951) Upper and Lower Sonoran and Transition Zones. Grinnell and Miller (1944), P. n. nuttallii: "rocky or gravelly terrain grown scatteringly to bushes or trees. Often associated with sage-brush, antelope-brush, pinon pines, or junipers." P. n. hueyi : "gravelly or stony desert floor or wash bot- toms sparsely grown to bushes or small trees." B. Altitudinal range Wauer (1964) noted at 3000-6000 ft., Panamint Mtns. Salt (1953), reports as resident of Boca Springs (6000 ft.), May through August. Miller (1955) "common along rocky can- yon walls at 5000 ft. but not noted higher up." Grinnell and Miller (1944), P. n. nuttallii: *1800 to 8300 feet." P. n. hueyi : "below T00U feet." C. Home range size D. Territory requirements Perch sites - Wetmore (1932) "rest during the day on the ground, though after night, when feeding or calling, may seek higher perches on stones or posts or on low branches." Courtship and mating sites - Nest sites - Orr (1948) "pine-needle-matted earth on which two eggs were deposited." Bent (1940), "The two eggs are laid on the bare ground, without any semblance of nest 4 building; a slight hollow may be scraped in the bare earth ...on hard gravelly ground... on a flat rock." % Phalaenoptilus nuttallii (con't.) E. Special habitat requirements F. Seasonal changes in habitat requirements Jaeger (1949), "the Poor-wills are rock seeking, hibernating birds in the winter." V FOOD A. Food preferences Brauner (1954) "Birds collected. . .had from 20-61 large beetles and noctuid moths in their stomachs." Stanford and Knowlton (1942) "Stomach contained 6 adult Lepidoptera; 1 mirid bug; 2 leafhoppers; 4 Diptera; and 1 click beetle." Bent (1940; "entirely of insects, mostly the smaller, night flying species, such as moths, beetles, chinch bugs, and locusts. ' B. Foraging areas Grinnell and Miller (1944), "seeks sandy riparian ground or even mud-bars in the river." C. Foraging strategies Bent (1940), "insects are caught on the wing in the capa- cious mouths. . .many are also picked up on the ground." D. Feeding Phenology Brauner (1952) "length of period of activity is apparently affected by weather conditions and phases of the moon. On days following or during a rainy period, the numbers of moths decreased and the period of Poor-will activity was longer. Under normal weather conditions moths were plenti- ful and the period of feeding was short." E. Energy requirements Jaeger (1948, 1949), describes torpor of presumably same individual for three successive winters, including body and ambient temperature measurements. "Known period of profound hibernation torpidity for the 1947-1948 season was about 85 days." (1949). Brauner (1952), "Prior to the period of torpidity the food supply available to Poor-wills under natural conditions is limited. It is at least possible that the onset of torpidity is associated with reduced food supply." Report includes body and ambient temperatures of captive individual. Marshall (1955), reports torpidity related to amount of food available. Ambient and body temperatures, respiration rates, and acitivity cycles under captive conditions. Bartholomew, Howell, and Cade (1957), Phalaertoptilus nuttallii (con't.) calculations of energy reserves, based upon measurements f-J* of oxygen consumption of captive individual active and in torpor. Arousal rates slow. "Reduced body temperature and torpor provide a means of energy conservation and are associated with. .. survival during long periods of fasting." Bartholomew and Howell (1959) reports on temperature, metabolic rates, and behavior for entry- torpor-arousal cycle in captivity. Howell and Bartholomew (1959), further studies on torpor in captivity. Bartholomew, Hudson, and Howell (1962), further studies of physiology related to temperature regulation and torpidity. VI REPRODUCTION A. Age at first breeding B. Territorial behavior Mengel, Sharpe, and Woolfenden (1972), "The exact behavioral functions of wing clapping are uncertain at present. .. sug- gests that such behavior is involved in territorial defense." Includes descriptions of wing-clapping. C. Courtship and mating behavior D. Nesting phenology ^~. v Dixon (1934), found 2 eggs (June 6) in nest on steep, well wooded western slope, 7000 ft. Snow on nearby ground 2 inches deep. Eggs on pebbles on ground. E. Length of incubation period F. Length of nestling period G. Growth rates H. Post-breeding behavior VII POPULATION PARAMETERS A. Clutch size Orr (1948), two eggs B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abundance 4 Phalaenoptilus nuttallii (con't.) F. Habitat density figures VIII INTERSPECIFIC INTERACTIONS A. Predation B. Competition C. Parasitism IX STATUS A. Past population trends Grinnell and Miller (1944), P. n. nuttallii: "Summer resi- dent to northward and at higKer altitudes; winter visitant at low altitudes at south common." P. n. hueyi : "Resident. Locally, fairly common." B. Present population status C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status 8 Phalaenoptilus nuttallii (con't.) XI LITERATURE CITED Abbott, C. G. 1940. Notes from the Salton Sea, California. Condor 42:265. American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bartholomew, G. A. and T. R. Howell. 1959. Further experi- ments on torpidity in the Poor-will. Condor 61:180-185. Bartholomew, G. A., T. R. Howell and T. J. Cade. 1957. Tor- pidity in the White- throated Swift, Anna Hummingbird, and Poor-will. Condor 59:145-155. Bartholomew, G. A., J. W. Hudson and T. R. Howell. 1962. Body temperatures, oxygen consumption, evaporative water loss, and heart rate in the Poor-will. Condor 64:117-125. Bendire, C. M. 1895. Life histories of North American birds. U.S. Nat. Mus. Spec. Bull. No. 3. Bent, A. C. 1940. Life histories of North American cuckoos, _ goatsuckers, hummingbirds and their allies. U.S. Nat. Mus. ^^ Bull. No. 176. Bickford, E. L. 1929. Notes from the Napa Valley. Condor 31: 35-36. Brauner, J. 1952. Reactions of Poor-wills to light and tem- perature. Condor 54:152-159. Cardiff, E. A. 1956. Additional records for the Imperial Valley and Salton Sea Area of California. Condor 58:447- 448. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39: 210-219. Culbertson, A. E. 1946. Occurrences of Poor-wills in the Sierran foothills in winter. Condor 48:158-159. Dawson, W. L. 1923. The birds of California. Vol. II. South Moulton Co., San Francisco. Dickey, D. R. 1928. A new Poor-will from the Colorado River Valley. Condor 30:152-153. Dixon, J. B. 1934. Records of the nesting of certain birds in eastern California. Condor 36:36. 4 Phalaenoptilus nuttallii (con't.) Gilman, M. F. 1935. Notes on birds in Death Valley. Condor 37:238-242. Grinnell, J. and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. Howell, T. R. and G. A. Bartholomew. 1959. Further experiments on Torpidity in the Poor-will. Condor 61:180-185. Jaeger, E. C. 1948. Does the Poor-will "hibernate"? Condor 50:45. Jaeger, E. C. 1949. Further observations on the hibernation of the Poor-will. Condor 51:105-109. Marshall, J. T. , Jr. 1955. Hibernation in captive goatsuckers. Condor 57:129-134. Mengel, R. M. , R. S. Sharpe and G. E. Woolfenden. 1972. Wing clapping in territorial and courtship behavior of the Chuck- wills- widow and Poor-will (Caprimulgidae) . Auk 89: 440-444. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. 50:531- 624. Miller, A. H. 1955. The avifauna of the Sierra del Carmen of Coahuila, Mexico. Condor 57:154-178. Orr, R. T. 1948. Nesting behavior of the Poor-will. Auk 65: 46-54. Peters, J. L. 1940. Checklist of birds of the world. Vol. IV. Mus. Comp. Zool. , Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co., Boston. Ridgway, R. 1914. The birds of North and Middle America. Part VI. Bull. U.S. Nat. Mus. No. 50. Salt, G. W. 1953. An ecologic analysis of three California avifaunas. Condor 55:258-273. Selander, R. K. 1954. A systematic review of the booming nighthawks of western North America. Condor 56:57-82. Small, A. 1974. The birds of California. Macmillan Co., New York. 10 Phalaenoptilus nuttallii (con't.) Stanford, J. S. and G. F. Knowlton. 1942. Food of some Utah birds. Auk 59:580-581. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Wetmore, A. 1932. Seeking the smallest feathered creatures. Nat. Geogr. Mag., Vol. 62:65-89. • <-» 4 » % RED-TAILED HAWK Buteo jamaicensis I TAXONOMY A. Type description Buteo jamaicensis calurus Cassin. (337b) - AOU (1957) Buteo calurus Cassin, Proc. Acad. Sci. Philadelphia, 7, Jan. -Feb. (May 22), 1855, p. 281. (Fort Webster (.Rio MimbresJ , New Mexico.) B. Current systematic treatments AOU (1957) Order Falconiformes, Suborder Cathartae, Super- family Cathartoidea, Family Cathartidae, subfamily Buteoninae, Genus Buteo, with 8 species; 7 subspecies of jamaicensis. Mayr and Short (1970), "The red-tailed 'buzzards' comprise a cosmopolitan group of allopatric, closely related species including B. jamaicensis, B. buteo, B. ventralis, B. oreophilus, and B. brachyp terus . These are believed to comprise a super species. Of these buteo and ventralis have been considered conspecific with jamaicensis and this may prove to be correct. We follow various authors in merging the western, melanic harlani as a race of jamaicensis. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Buteo borealis ; Buteo harlani ; B. montanus ; B. calurus ; B. borealis calurus; B. b. socorroensis ; B. jamaicensis*~boreali"s ; B. j. fuertisi. Knowlton (19097 refers to B. j . calurus as B. borealis calurus. Grinnell (1915) same as Grinnell and Miller (1944), Bent (1937) calls this subspecies B. borealis calurus . D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Red-tailed Buzzard; Harlan Hawk; Red- tailed Hawk; California Red- tail; Western Red- tail; Black Red-tailed Hawk; Western Hen Hawk; Texas Red-tailed Hawk. May (1935), Hen Hawk, Chicken Hawk, Squealing Hawk, Buzzard Hawk. II DESCRIPTION A. External morphology of adults Dawson (1923) Above dark brown or sooty brown, color nearly pure on back and minor wing coverts, elsewhere much varied by lighter grayish brown, tawny, and outcropping white; long scapulars and tertials dusky and white, and double- tawny barred; wing when folded usually, but not always, Buteo jamaicensis (con't.) 2 inches short of tail; tail rich orange- rufous, crossed near tip by narrow black band; underparts white and variously broad-marked or washed, except on throat, with pale cinammon- rufous most heavily on sides of breast; throat and breast sparingly marked with blackish shaft streaks; bill plumbeous; tarsus yellow, very stout; claws black. The adults do have a melanistic phase in which the entire plumage, except tail and its coverts, is chocolate brown or blackish, rich deep rusty usually warming on the breast, and lighter rufous appearing on the shanks. Many gradations exist between these two plumages. Peterson (1961) - Large, broad-winged hawk; rufous underside of the tail can be seen in flight. From beneath, adults have whitish tails. Underparts are "zoned" (light breast, broad band of streakings across belly). There is much variation. Black adults usually show red tails (unlike other Buteos). Robbins et al. (1966) say the best field marks are the uniformly colored tail, reddish above, light pink beneath, and the dark belly band. May (1935) says the Western Red- tail is especially noted for the wide variation in its colors. Friedmann (1950) gives sizes for adults and voung and descriptions of plumage. Snyder and Wiley (1976) give sizes of all North American hawks and owls. B. External morphology of subadult age class Dawson (1923) - above much as in adult, but showing less of tawny and more outcropping of white; tail entirely diff- erent, grayish brown crossed by ten or twelve brace-shaped or waved bands of dusky; upper tail coverts lighter, dusky and whitish barred, with a mixture of ochraceous; underparts white or pale ochraceous buffy, heavily streaked, spotted, and posteriorly barred with brown except on breast which is nearly immaculate. Immatures frequently show strong melanistic tendency, in which case the spotting of the under- parts invades the breast and increases elsewhere nearly to the point of confluence. Robbins et al. (1966). "The tail of the immature is finely streaked." May (1935): "Young Red- tails usually lack the 'wrist-mark' and the dark tips of the flight feathers are less marked than in the adult." C. Distinguishing characteristics Interspecific - Dawson (1923), stouter proportions and more regal bearing than B. swainsoni , but not always distinguishable from that species in the field. Peterson (1961), Red- shouldered has a banded tail and is more uniformly patterned below, also is chunkier with wider wings, shorter tail. May (1935) <- 4 Buteo jamaicensis (con't.) say young Red-tails are very difficult to tell from young Red- shoulders in the field, also the flight of Red- shouldered is more rapid, buoyant and owl-like. The American Rough-leg and the Ferruginois Rough- leg are slightly larger. Phillips et al. (1964), "...it does not gather into flocks as does swainsoni." Intraspecific - Brown and Amadon (1968), "Adults and young tend to be more heavily marked below" than other races. Baird et al. (1905), "Adult. Similar to borealis, but darker, with more rufous and blackish in the plumage." The young Red-tails, according to Baird et al. (1955), of the var. calurus have numerous heavy transverse spots on the tibia while those of the var. borealis are almost perfectly white. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), Breeds from central interior Alaska (Circle, Tanana River), Yukon, (Forty Mile), west-central Mackenzie and Saskatchewan south to Baja California, Sonora, and western New Mexico, ranging east to Colorado, Wyoming, and Montana and to northeastern Manitoba, south-central Ontario, central and eastern Quebec, Prince Edward Island, and Cape Breton Island, Casual in Illinois, southern Ontario, Mississippi, Pennsylvania, and New Jersey. Grinnell and Miller (1944), Well-nigh universal: from most arid to rain- iest belts; from below- sea- level "sinks" to at least 12,000 feet altitude on Sierra Nevada; on deserts and on most is- lands. Has actually been found nesting under such extreme conditions as are affordable in the following places: Colo- rado desert; Mohave desert; Lava Beds National Monument, Siskiyou County; Lake Tahoe; Humboldt County; Anacapa Island; Santa Catalina Island; Santa Cruz Island. Breeding metro- polis, however, seems to lie in Upper Sonoran and Transition Life-Zones. Dawson (1923), Western North America, except the coastal district of southeastern Alaska, from central Yukon and western Mackenzie south to Cape San Lucas and cen- tral America; east to the western borders of the Great Plains and casually to Ontario. Gullian et al. (1959) say that Red- tails are common spring and fall migrants in Nevada but scarcer in July and in the winter. Bent (1937), "From the western edge of the Great Plains westward. .. from southeastern Alaska and central western Mackenzie southward to Mexico." • Buteo jamaicensis ( con ' t . ) B. California distribution of the species Dawson (1923), "Common resident of the widest distribution. Breeds from Lower Sonoran deserts to the limits of Upper Transition." Grinnell (1915), "Common resident almost through- out the state. Recorded from deserts, islands, lowest valleys and highest mountains, from most arid to rainiest belts." Baird et al. (1905), "...stated to be common in all parts of the state not destitute of trees, and to re- side permanently wherever found, pairing only during the breeding season." Small (1974), 'Common resident; small numbers are transient. .. length of state; breeds in almost any suitable habitat with cliffs or tall trees for nesting or roosting." Bent (1937) reports Red- tails occurring on the Farallons during migration. C. California desert distribution Willet (1951) calls calurus a permanent resident of the southern California desert. Phillips et al. (1964) do not list California desert distribution but do say that Red- tails nest in desert areas in Arizona, using saguaros or low shrubs for nest sites. Wauer (1964) says that the cliffs at the canyon mouths of the Panamint Mountains and the side washes provide nesting sites for the Red- tails. They utilize the high cliffs and ledges. Hensley (1959) reports Red- tails nesting in the Sonoran Desert. D. Seasonal variations in distribution AOU (1957), Winters from southwestern British Columbia to southern Minnesota and south and southwest across its breed- ing range to Guatemala and northern Nicaragua; east to Louisiana. Brown and Amadon (1968), "In the more northern parts of its range it is quite migratory. . .nevertheless, many winter in areas that are often snowbound." Bent (1937) says the Red-tail is migratory in its northern range, leaving the Yellowstone Park area in the middle of October and returning again in late March, early April. IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), Terrain affording food ordinarily in the form of rodents, and nesting sites in trees or cliffs more or less inaccessible to potential dispoilers. Perhaps nearest ideal: interspersed woodland and open grassland, the latter in predominance. Dawson (1923), "Possesses great adaptability, so that it is able to maintain itself as well upon the Colorado and Mohave deserts as upon the M Buteo jamaicensis (con't.) middle slopes of the Sierras and the jutting cliffs of the boundless chaparral country. Baird et al. (1905) published a report from Mr. Dresser who says in Texas they prefer heavily timbered country. Wauer (1964) says Red- tails are rarely observed above the pinon woodlands during the colder winter days. Mader (1978; found Red- tails nesting in flatlands, grasslands, woodland, mountainous desert. B. Altitudinal range Grinnell and Miller (1944) and Dawson (1923), breeds up to the limits of the Upper Transition zone and wanders in to the Boreal. Wauer (1964) report a nest at 2500 feet in the Panamint Mountains. C. Home range size Braun and Amadon (1968), "The nesting range of a pair varies from about a third to two and a half square miles." Fitch et al. (1946) reported territories of 80 to 200 acres in the San Joaquin area of California. Most territories were oval or circular. Frequently a ridge limited a range ex- tension. D. Territory requirements Perch sites - Brown and Amadon (1968), "Night roosts in winter are in thick conifers. High perches are favored. May (1935) says they perch for hours at a time, usually in a dead tree or on a mountain ledge. Fitch et al. (1946) found Digger pines to be the most popular perch sites in the San Joaquin area, favored because of their great heights and open crowns. Live oaks were generally not suitable due to the dense outer foliage. Courtship and mating sites - Brown and Amadon (1968) des- cribe courtship in the air, as do Grossman and Hamlet (1964), It appears from these two references that part of the court- ship takes place at the nest, during an extended construc- tion period when the birds are very sensitive to dis- turbance. Fitch et al. (1946) describe a pair soaring and calling loudly during courtship. The male will often fly above the female and dangle his legs near her. Flights usually last from 5 to 10 minutes. Nest sites - Dawson (1923), crannies or ledges of cliff or high in trees made of sticks lined with bark strips or grass. Knowlton (1909); "placed in a tree, usually 50 or 60 feet from the ground. Brown and Amadon (1968), "...are often placed in commanding positions in trees, but in the Buteo jamaicensis (con't.) desert may be in cactus 12 or 15 feet from the ground, occasionally on rock pinacles, ledges or even a steel tower." Grossman and Hamlet (1964) state that Red- tails nest in the highest trees they can find: 35 to 70 feet from the ground. Phillips et al. (1964), "Common nest sites are crotches of tall trees or saguaros." Wiley (1975) found 71.7% of nests in sycamores, 17.0% in oaks, 7.5% in Eucalyptus, and 3.8% on cliff faces in Orange County, California. Sycamores were the most common tree. Seidensticker and Reynolds (1971) found 747o of 55 nests in cottonwood trees, 4 in Doublas fir, 3 on cliffs, 3 in dead snaps, 2 in aspen, 1 in Engelmann spruce and 1 in limber pine. Cottonwoods were the only common tall trees growing on the river. Fitch et al. (1946) and others report that old nest sites are reused. E. Special habitat requirements Brown and Amadon (1968) say that adequate perches and nesting trees are vital. Usually they perch on dead snaps, although in hot weather they may seek shade. Fitch (1946) believes perch sites to be the most essential feature of a territory. F. Seasonal changes in habitat requirements Brown and Amadon (1968) state that territories are still defended in winter against other pairs of the same species. V FOOD A. Food preferences Knowlton (1909), "It occasionally makes off with a meal of young poultry, or a game bird... its food consists princi- pally of mice and other small rodents. .. reptiles, frogs and insects, and only rarely of poultry or game birds." Brown and Amadon (1968), "The Red-tail sometimes kills a snake, rabbit or ground squirrel." In winter they eat mostly mice in some areas, also catch lizards and sometimes small birds. Small and medium-sized rodents and rabbits are the staple items. The Socorro Island race feeds on land crabs and birds. In May (1935) there is a report on a study done by the Bureau of Biological Survey which found in 850 stomach samples taken in nearly all parts of the United States 86% mammal remains, 12% poultry or game bird remains, 8% other birds, 8% reptiles and 15% insects. Fitch et al. (1946) found of 625 prey items; 23 species, the major area of which were, 380 ground squirrels, 79 pocket gophers, 62 cottontails, 13 wood rats, 10 kangaroo rats and 8 chipmunks. They do cast pellets and these generally do not contain bone, which is ^fe digested, but consist of hair, feathers or scales. They I describe prey items from various times of the year and local- ities. • • Buteo jamaicensis (con't.) B. Foraging areas Robbins et al. (1966), "...feeds in open country." Baird et al. (1905), "It is said to generally descend upon its prey from some fixed position, as a branch of a tree. It is a cautious bird and rarely ventures near a house for poultry except when the dwelling is isolated and near its own haunts." C. Foraging strategies Brown and Amadon (1968), "Pairs fly from hunting perch to hunting perch in their territories, not always together. When leaving the nigh roost they may have a warm-up flight of up to one hour before beginning to feed. More strikes at prey are unsuccessful than successful. In some areas most prey is sighted from a lookout, often a high one. The hawk often smashes recklessly through small brush for its prey. It also hunts on the wing, gliding low over hillsides and swooping down." Baird et al. (1905) says Red- tails rarely dart down to catch a prey while flying, and after catching a prey they fly off with it a ways to eat it. Snyder and Wiley (1976) discuss sexual differences in food eaten by North American accipiters. Grier (1971), "The change to alert posture in a relaxed bird that would attack was very noticeable. . .changes of tail angle. The time required for a bird to leave its perch. . .depend largely on the birds familiarity with the situation." Snyder (1975) determined that Red-tails choose the larger prey item when given a choice of two. Fitch et al. (1946) describe two methods of foraging; waiting on a high perch and dropping upon a prey with a direct swoop, and quartering back and forth in low flight to drop on an animal in the open. The first method is most common. D. Feeding phenology Brown and Amadon (1968), "In winter in some areas it lives almost exclusively on meadow mice (Micro tus) , especially the young hawks of the year. It also takes medium or fairly large birds, chiefly caught on the ground. Grossman and Hamlet (1964) suggest that Red- tails feed more on birds during the fall migration when many small birds are visible. May (1935) reports that W. L. Finley (1905) says when the Columbia River overflowed, a pair of Western Red- tails fed their young on carp and catfish. May (1935) also has a report from F. H. Chittenden (1911) that Red- tails eat potato bugs at times. Snyder and Wiley (1976) discuss breeding season food habits of North American accipiters and the relationship between prey populations and timing of breeding. Hofner (1974), ...it appears that males Buteo jamaicensis (con't.) occur as prey of Red- tailed Hawks exclusively during winter and spring." Fitch et al. (1946) say that prey items are clearly influenced by the season and what is available. Hensley (1959) found the most active feeding times to be 8 to 9 a.m. and 5 p.m. E. Energy requirements Brown and Amadon (1968), "In captivity in winter a Red- tail will eat about 135 grams per day." The adults often bring more food to nestlings than they can eat. Snyder and Wiley (1976) discuss the division of labor between sexes in accipiters and the amounts of food required and also feeding rates at nests with different brood sizes. VI REPRODUCTION A. Age at first breeding Luttich et al. (1971) believe it takes 6 years from hatch- ing for a Red- tail to produce a young. B. Territorial behavior Brown and Amadon (1968), Territories are defended even in winter. Grossman and Hamlet (1964); After returning to breeding grounds in late February or early March, they begin to make sounds and movements around the nesting territory of last year, becoming more beligerent in boundary disputes as the days pass. C. Courtship and mating behavior Knowlton (1909) notes that Red- tails circle about in the air chasing each other and high, shrill calls. Brown and Amadon (1968); "...the pair soar about, screaming frequently, the male often somewhat behind the female... the female sometimes rolling over in mock combat and presenting her talons. The male sometimes performs a series of shallow dives, and flights may terminate by a series of dives end- ing at a perch; or he may pull up from a dive to continue soaring. The flights may occur at any time of year in fine weather, but are regular only at the onset of breeding. Mating follows such flights. Presumably courtship feeding occurs." Conner (1974) reports an unusual addition to the normal courtship flight of the Red- tail. A pair in Virginia performed the typical dives and ascents as they swirled in a thermal and then the male, while above the female, reached down and grasped her back with its claws. The contact lasted 2 seconds. • • % » Buteo jamaicensis (con't.) D. Nesting phenology Dawson (1923), "February 15th-May 1st, according to lati- tude and altitude; one brood." Brown and Araadon (1968), "Nests may be built as early as January in regions where incubation does not begin until March.: Phillips et al. (1964) say that young hatch around April 9-12 on deserts in Arizona. Snyder and Wiley (1976) state that a factor contributing to early reproduction in some raptors preying on mammals may be the susceptibility of their young to pre- dation by other raptors. Wiley (1975) gives laying dates in Orange County as from 5 March to 21 April, hatching dates from 6 April to 23 May, fledging dates from 16 May to 1 July. Seidensticker and Reynolds (1971): 1st egg hatched 29 March, last brood fledged 20 June, whole season in 1967 was 125 days. Mader (1978) says that Red-tails began nesting in the Sonoran desert in late December through February. Laying occurred from 25 February through 2 April. Fledging centered around the last week in May and 1st week in June. Luttich et al. (1971) report Red-tails first appearing in their northern breeding range in early April and departing by mid-October. The first incubation begins during the second week in April. E. Length of incubation period Brown and Amadon (1968), 28-32 days, usually 30. Grossman and Hamlet (1964), 34 days. Bent (1937), 28 days. F. Length of nestling period Brown and Amadon (1968), about 45 days. Grossman and Ham- let (1964), about 6 weeks. Wiley (1975), "41 days," in Orange County, California. In nests that were not disturbed during the later part of the nesting stage fledging dates averaged 47 days. Luttich et al. (1974) give a nestling stage of 44 days. Fitch et al. (1946), 45 or 46 days. G. Growth rates Brown and Amadon (1968), "On its second day the chick is very active when awake, bouncing around, flapping the wings. At 6 or 7 days it pecks at prey. At 10 days the young whistles back at its parent screaming above. At 16 days feathers are appearing, the young become aggressive." Grossman and Hamlet (1964); At 17 days their wing quills appear, closely followed by... the tail." Fitch et al. (1946), "At 16 days the nestlings begin to acquire feathers. Within a month or more of age the young begin to flap and stretch their wings..." 10 « Buteo jamaicensis ( con ' t . ) H. Post-breeding behavior Brown and Amadon (1968), "After leaving the nest the young gradually learn to hunt." Grossmann and Hamlet (1964; state that new- flying hawks are fairly inactive in summer since they require little food for their bodies to maintain normal temperatures. In the late summer they spend most of their days and nights in the cool, shaded forest. Snyder and Wiley (1976) say that long periods of fledgling dependence are known for some raptors eating mainly mammals, including Red- tails. Mader (1978) says that young may be dependent on their parents for 30 to 70 days after fledging. VII POPULATION PARAMETERS A. Clutch size Dawson (1923), 2 or 3, rarely 4, 5. White or pale bluish white, lightly stained, spotted, blotched, or smeared with reddish brown. Brown and Amadon (1968), 1 to 3, even 4, with some geographical variation. Both sexes incubate, although the female does most. Mader (1978) gives 2.32 eggs per nest. Luttich et al. (1971) give 2.1 eggs per nest. B. Fledging success Brown and Amadon (1968) report that 38 eggs produced 16 fledglings in California, and in 1 year in Wisconsin, 48 young were produced in 27 nests. Wiley (1975) found overall nest success in Orange County, California, to be 73.6% and states that other reports ranged from 50% to 74%. Seidensticker and Reynolds (1971) found fledging success to be 1.7 + 0.2 per successful nest. Mader (1978) had 81% of 42 nests successful. Luttich et al. (1971) reported 1.4 young fledged per hatched clutch. C. Mortality rates per age class Brown and Amadon (1968), "Young sometimes fall out of the nest and die." Snyder and Wiley (1976) state that repro- ductive losses early in the breeding cycle are generally uncommon in North American accipiters. In 1971, a year of bad drought and thus low food supply, many pairs failed to lay or deserted eggs." Generally losses early in the nestling season involved the runts of broods." There is almost no loss of young late in the season. Wiley (1975) reported 25% of the nests he was observing in Orange County, California, failed before or during incubation, 75% failed during the nestling period. No young were fledged ^^ from 60.0% of the nests in that area. Land development and JH farming disturbances were responsible for the high failure i 11 Buteo jamaicensis (con't.) rate. Luttich et al. (1971) consider an adult mortality rate of 207o annually to be normal and believe a 1st year rate of 51% is normal. D. Longevity Kennard (1975) lists the oldest banded Red- tail as 13 years 7 months E. Seasonal abundance F. Habitat density figures Dawson (1923), "...after the American Kestrel, the Western Red- tail is still the commonest hawk in California," Brown and Amadon (1968), "In southern Wisconsin, nesting popula- tions averaged 0.29 pairs per square mile in one year, 0.41 in another, only one- fifth as many as in optimum habitat in California where breeding ranges maybe as little as..." 2 pairs per square mile. "A 37 square-mile tract in Michigan had 2 nesting pairs in one year, but had 5 when checked a year later. In Wyoming there were 12 pairs on. a 12 mile square tract." Wiley (1975), in Orange County found dis- tances between adjacent nests to be 150 m to 2.09 km (aver- age, 0.84 km). Seidensticker and Reynolds (1971) found internest distances to range from 3.1 miles to 0.2 mile (average 1.3 miles). Luttich et al. (1971) in Alberta found a habitat density of one pair per 2.7 square miles. Fitch et al. (1946) found one pair to a half square mile in the San Joaquin area. VIII INTERSPECIFIC INTERACTIONS A. Predation Brown and Amadon (1968) give a report of Scrub Jays (Aphelecoma) annoying incubating adult Red- tails until they desert their nests, then sucking the eggs dry. Blood Sucking flies swarm in wet years and kill some downy young. Barney (1959) reports a Red- tail dive-bombing a new born lamb and killing it. Fitch et al. (1946) record one instance of a California Jay robbing a nest. B. Competition Schnell (1968), "The winter ranges of the Rough-legged and Red- tailed Hawk overlap to some extent across much of the U.S. These species are congeneric, similar in size and anatomy, and have roughly similar food habits." % 12 Buteo jamaicensis (con't.) C. Parasitism Seidensticker and Reynolds (1971) found blood sucking dipterous larva on almost all hawk nestlings, but could attribute no mortality to these larvae. Fitch et al. (1946) reported 7 nestlings being killed by blood-sucking flies in the San Joaquin area. IX STATUS A. Past population trends B. Present population status Grinnell and Miller (1944), "Common and widespread; numbers holding up, probably close to normal save in lowland area thickly settled by humans, where marked reduction or even, locally, elimination has taken place." Knowlton (1909) remarks that Red-tails are deserving of protection since they eat the destructive rodents from farmer's fields. Seidensticker and Reynolds (1971), "Henny and Wight (in press) reported Red-tailed Hawk populations in the U.S. maintaining themselves." Luttich et al. (1971) believe their population in Alberta is not maintaining itself. C. Population limiting factors May (1935) says that farmers have killed Red- tailed Hawks because sometimes the hawks will acquire a taste for chick- ens after finding and eating a few strays. The good they do by eating rodents in fields far outweighs the bad. Phillips et al. (1964), "...many are shot by the ignorant, who suppose they are all killers of chickens." Fitch et al. (1946) and others comment on nest desertion caused by in- vestigators to the extent that this appears to be a real problem. Fitch et al. (1946) say that food supply for the young is not a limiting factor. D. Environmental quality: adverse impacts Seidensticker and Reynolds (1971) found no build up of chloronated hydrocarbons in breast muscle of newly hatched young or fledglings but there was a decrease in eggshell thickness from pre-DDT levels. E. Potential for endangered status i • 13 Buteo jamaicensis ( con ' t . ) XI LITERATURE CITED American Ornithologists Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Baird, S. F., T. M. Brewer and R. Ridgway. 1905. A history of North American Birds. Vol. 3. Little, Brown, and Co., Boston. Barney, Merle D. 1959. Red- tailed Hawk killing a Lamb. Condor 61:157-158. Bent, Arthur Cleveland. 1937. Life histories of North Amer- ican birds of prey. U.S. Nat. Mus. Bui. 167:1-409. Braun, Leslie and Dean Amadon. 1968. Eagles, Hawks and Falcons of the world. Vol. 2. McGraw-Hill Book Co. New York. 945 pp. Clevenger, G. A. and Aryan I. Roest. 1974. Cannibalism in Red-tailed Hawk. Auk 91:639.. Canner, Richard N. 1974. A note on aerial courtship of Red- tailed Hawks. Bird-Banding 45:269. Craighead, Frank. and John Craighead. 1939. Hawks in the Hand. Houghton Mifflin Company. Boston. 290 pp. Dawson, W. L. 1923. The birds of California. Vol. 4. South Moulton Co., San Francisco. Fitch, Henry S., Freeman Swenson and Daniel F. Tillotson. 1946. Behavior and Food Habits of the Red-tailed Hawk. Condor 48:205-237. Friedmann, H. 1950. The birds of North and Middle America. Part 11. United States Natl. Mus. Bui. 50. Grier, James W. 1971. Pre-attack posture of the Red-tailed Hawk. The Wil. Bui. 83:115-123. Grinnell, Joseph. 1915. A distributional list of the birds of California. Pacific Coast Avifauna No. 11. Grinnell, Joseph and Alden H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna, No. 27. 608 pp. Grossman, Mary Louise and John Hamlet. 1964. Birds of prey of the world. Clarkson N. Potter, Inc. , New York. 496 pp. 14 Buteo jamaicensis ( con ' t . ) Gullion, Gordon W. , Warren M. Pulich and Fred G. Evenden. 1959. Notes on the occurrence of birds in southern Nevada. Condor 61:278-297. Hafner, John C. 1974. Seasonal predation on moles by the Red- tailed Hawk. Condor 76:225. Hagar, Donald C. 1957. Nesting populations of Red- tailed Hawks and Horned Owls in central New York state. Wil. Bui. 69:263-272. Hardy, Ross. 1939. Nesting habits of the Western Red- tailed Hawk. Condor 41:79-80. Hensley, M. Max. 1959. Notes on the nesting of selected species of birds of the Sonoran Desert. Wil, Bui. 71: 86-92. Hubbard, John P. 1965. The summer birds of the forests of the Megal Ion Mountains, New Mexico. Condor 67:404-415. Kennard, John H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. Kilham, Lawrence. 1964. Interspecific relations of crows and Red- shouldered Hawks in mobbing behavior. Condor 66:247- 248. Knowlton, Frank H. 1909. Birds of the World. Henry Holt and Co., New York. 873 pp. Luttich, Stuart H. , Lloyd B. Keith and J. D. Stephenson. 1971. Population dynamics of the Red- tailed Hawk (Buteo jamaicensis) at Rochester, Alberta. Auk 88:75-87. Mader, William J. 1978. A comparative nesting study of Red- tailed Hawks and Harris Hawks in southern Arizona. Auk 95:327-337. May, John Bichard. 1935. The hawks of North America. National Association of Audubon Societies, New York. 140 pp. Mayr, Ernst and Lester Short. 1970. Species taxa of North American birds. Publication of the Nuttall Ornithological Club, No. 9. Cambridge. Orians, Gordon and Frank Kuhlman. 1956. Red- tailed Hawk and Horned Owl Populations in Wisconsin. Condor 58:371-385. Peterson, R. T. 1961. A field guide to Western birds. 2nd Edition. Houghton Mifflin Co., Boston, 366 pp. • 15 Buteo jamai cens is (con't.) Phillips, Allan, Joe Marshall and Gale Monson. 1964. The birds of Arizona. Univ. of Arizona Press, Tucson. 212 pp. Robbins, C. S. , B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Schnell, Gary D. 1968. Differential habitat utilization by wintering Rough- legged and Red- tailed Hawks. Condor 70: 373-377. Seidensticker, John C. and Harry V. Reynolds. 1971. The nesting, reproductive performance, and chlorinated hydro- carbon residues in the Red- tailed Hawk and Great Horned Owl in south-central Montana. The Wil. Bui. 83:408-418. Small, Arnold. 1974. The birds of California. Winchester Press, New York. 310 pp. Snyder, Noel F. R. and James W. Wiley. 1976. Sexual size dimorphism in hawks and owls of North America. Ornitholo- gical Monog. No. 20. Am. Ornith. Union. Snyder, Rowl. "1975. Some prey preference factors for a Red- tailed Hawk. Auk 92:547-552. Stahlecker, Dale W. and A. William Alldredge. 1976. The impact of an underground nuclear fracturing experiment on cliff -nesting raptors. Condor 88:151-154. Wauer, Roland H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Wiley, James. 1975a. The nesting and reproductive success of Red- tailed Hawks and Red- shouldered Hawks in Orange County, California, 1973. Condor 77:133-139. Wiley, James W. 1975b. Three adult Red-tailed Hawks tending a nest. Condor 77:480-482. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. • RED-WINGED BLACKBIRD Agelaius phoeniceus TAXONOMY A. Type description Agelaius phoeniceus nevadensis - AOU (1957), A. p. nevadensis Grinneli, Proc. Biol. Soc. Washington, 27, May IT, 1914, p. 107. (Quinn River Crossing, Humboldt County, Nevada.) Aeglaius phoeniceus aciculatus ^ AOU (1957), A. p. aciculatus Mailliard, Condor, 17, no. 1, Jan. 30, 1915, p. 13. (Isabella, Kern County, California.) Agelaius phoeniceus sonoriensis - AOU (1957), A. p_. sonoriensis Ridgway, Man, North Amer. Birds, 1887, p. 370. ( Southern California and Arizona to Mexico = Old Camp Grant, lower San Pedro River, Arizona.) B. Current systematic treatments AOU (1957) considers A. phoenicens a member of the Order Passeriformes and recognizes 14 subspecies. It is in the Family Icteridae. Mayr and Short (1970) say that a study is needed on the continent wide variation of this species. Phillips et al. (1964) publish a new spelling for sonoriensis which they say is correct; sonorensis. C. Synonomies of scientific nomenclature A. p_. nevadensis - Grinneli (1944), A. gubernator, part; A. p. neutralis, A. p. calif ornicus, A. p. aciculatus, A. £. fortis, A. p. mailliardorumr" A. p_. sonorensis - Grinneli (1944), A. gubernator, A. p_. Tongriostris, A. £. neutralis, A. £. thermophilus. D. Synonomies of vernacular nomenclature A. p. nevadensis - Grinneli (1944), Crimson- shouldered Blackbird, Bicolored Blackbird, San Diego Redwing, California Bi-colored Blackbird, Nevada Redwing, Kern Red-winged Black- bird, Great Basin Red-winged Blackbird, Thickbilled Red-winged Blackbird. A. £. aciculatus - Grinneli (1944), Kern Red-winged Blackbird. A. £. sonoriensis - Grinneli (1944), Red- shouldered Blackbird, Red-winged Blackbird, Sonoran Redwing, San Diego Redwing. Agelaius phoeniceus (con't.) II DESCRIPTION A. External morphology of adults A. p_. sonoriensis - Dawson (1923), Plumage glossy black, Tesser wing coverts red; middle of coverts ochraceous orange (male in spring). Female: general plumage streaked dusky and white; above bordered with dusky and grayish and dull ochraceous; below heavily streaked or striped dusky and white, clearing on chin and upper throat. There may be faint bluish or greenish reflections in the back of the male. Bill and feet are black. The middle coverts of the male which are largely hidden are ochraceous buff to ochraceous tawny, often shading on tips to whitish. A. p_. nevadensis - Dawson (1923), in shape of bill and general characters closely similar to sonoriensis; male scarcely distinguishable, but female conspicuously darker colored on account of the great relative breadth of the black streaking both above and below. A. £. aciculatus - Dawson (1923), similar to A. p_. neutralis, But of larger size, feet averaging somewhat larger, but chiefly characterized by a longer and more slender bill than any other form of this genus in the United States. Ridgway (1915) provides a key to the subspecies of Red-wings. B. External morphology of subadult age classes Dawson (1923) only gives a description for the immature age classes for A. £. neutralis. Immature male: like adult male in autumn, But with strong increase of marginal edgings of ochraceous; markings heavier above, lighter below, but only throat, crissum, and tail immaculate; the lesser wing coverts orange or tawny with skirtings of black; middle coverts entirely black, tipped with buffy white. Increasing age is marked by increasing redness of the lesser wing coverts, so that only the older males achieve spectrum red- ness. Immature female: like adult female and not certainly di s tingui shabl e . C. Distinguishing characteristics Interspecific - Robbins et al. (1966), The red- shouldered male can be confused only with the western Tricolored Black- bird. < i k Agelaius phoeniceus (con't.) Intraspecific - A. p. sonoriensis - Dawson (1923), similar to A. p_. neutralTs but male slightly larger and with a more slender bill. The adult female lighter with streaks more strongly contrasted above, those of lower parts rather narrower and not so dark, the upper parts more extensively dusky. Bent (1928), of the slender-billed nevadensis- caurinus chain. Bill longer and more slender than nevadensis. Female is lightest of California races. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) - A. phoeniceus : Northwestern British Columbia, southeastern Yukon, central Mackenzie, northern Saskatchewan, north-central Manitoba, northern Ontario, southern Quebec, Prince Edward Island, and central Nova Scotia south to southern Baja California, Costa Rica, western Cuba, the Isle of Pines, and the northern Bahamas. A. £. nevadensis - AOU (1957), Breeds from central southern and southeastern British Columbia (Kamloops Newgate) south through central Washington (Conconully, North Dalles), northern Idaho (Coeur d'Alene, Lewiston), eastern Oregon (Gateway, f Prospect), and central northern and eastern California (Seiad Valley, Yosemite, Little Lake) to southeastern Calif- ornia (Victorville, Death Valley) and southern Nevada (Ash Meadows) . A. p_. aciculatus - AOU (1957), Breeds in the mountain valleys of east-central Kern County, south-central California (Bod- fish, Isabella, Weldon, Onyx). A. d_. sonoriensis - AOU (1957), Resident from southeastern California (Indio), southern Nevada (opposite Fort Mohave, Arizona), central western, central, and southeastern Arizona (Fort Mohave, Wikieup, Safford) south to northeastern Baja California (Colorado Delta) and northern Sonora. B. California distribution of the species A. p_. nevadensis - Grinnell (1944), Breeds from Modoc Plateau, west to Shasta Valley and upper Klamath River drainage and in western edge of Great Basin south through Mono and Inyo Counties to Owens Valley; also disconnectedly on the Mohave Desert to the Mohave River, San Bernardino County. Occurs along some stream courses in the Sierra Nevada and Cascade Mountains; on the Pacific slopes of these mountains at middle levels. Grinnell (1915), common resident in suitable parts of Modoc and Inyo areas. Dawson (1923), The plateau region of northeastern California and the eastern slopes of the Sierras south to Lane Pine. Agelaius phoeniceus (con't.) A. p_. aciculatus - Grinnell (1944), In nesting season, restricted area in the mountain valleys of east-central Kern County. Life-zone, Upper Sonoran. Dawson (1923), east-central Kern County. A. £. sonoriensis - Grinnell (1944), Colorado River Valley "From Nevada line to Mexican border and irrigated parts of Imperial and Coachella Valleys north and west to vicinity of Indio, Riverside County. Dawson (1923), Resident in the Imperial Valley, on the Colorado Desert west to Mecca, and in the valley of the Colorado River north to Needles. Bent (1958), southeastern California. C. California desert distribution A. p_. nevadensis - Grinnell (1944), through Inyo area to Owens Valley; also disconnectedly on the Mohave Desert, to the Mohave River, San Bernardino County. Has been reported in Inyo, Mono, Los Angeles, San Bernardino, Kern and River- side Counties. Willett (1951), resident of damp localities on Mohave Desert, south of Mohave River. A. £. aciculatus - Grinnell (1944), restricted area in the mountain valleys of Kern County. A single specimen of doubtful identity was taken in Riverside County. Willett ^g (1951) doesn't list this subspecies as a resident of southern ^ California deserts. Bent (1958), east-central Kern County, California, in the Walker Basin. A. p_. sonoriensis - Grinnell (1944), in irrigated parts of Tmperial and Coachella Valleys, north and west to the vicinity of Riverside County. Northwestern record station, 7 miles west of Indio, Riverside County. Stragglers reported from San Bernardino and San Diego Counties. Willett (1951), Resident Colorado River, Imperial, and Coachella Valleys. D. Seasonal variations in distributions A. p. nevadensis - Grinnell (1944), Move southward and west- ward from breeding range. Fairly common in winter, west of the Sierra Nevada. Found in winter in coast districts of San Francisco Bay southward. A. £. aciculatus - Grinnell (1944), moves away from nesting grounds m winter. A. p. sonoriensis - Grinnell (1944), There is much local shifting of populations in winter and some wandering to points outside the breeding range takes place. Meanley (1965) reports that several geographic races may roost together after the breeding season. • Agelaius phoeniceus (con't.) IV HABITAT A. Biotopic affinities A._p_. nevadensis - GrinneLl (1944), Life-zones in summer, Tower Sonoran, Upper Sonoran, Transition. In summer found around fresh-water marshes and margins of ponds, lakes and slow moving streams grown with dense sedges, cattails, wil- lows. A. p. aciculatus - Grinnell (1944), Marshy meadows and lagoons wnich support growth of cattails and sedges. A. £. sonoriensis - Grinnell (1944), Life-zone, Lower Sonoran. For nesting, willow thickets, patches of tules and cattails, crowns of tall cottonwoods and the non-native tamarisk trees in the vicinity of water. B. Altitudinal range C. Home range size Orians (1973) found territories varying in size from 1,022 square m to 4,343 sq. m, with a mean of 2,361 square m. D. Territory requirements Perch sites - Meanley (1965) discusses Redwing roosts, say- ing they form roosts during every month of the year. After the breeding season they congregate mainly in wetland habi- tat. A source of water is important at a roost site. Redwings use dry sites as well as wetlands for roosting though; deciduous thickets, coniferous stands, canebrakes. Courtship and mating sites - Bent (1958) considers Redwings polygamous, as do Goddard and Board (1967) and others. Nest sites - Bent (1958), "...nests being placed low down in tufts of grass, in marsh vegetation, in various shrubs near water, or as high as 5 to 10 feet from the ground in willows." He also reports them in tules. Peterson (1961) Breeds in marshes, swamps, hayfields. Nests are built in tules, reeds, deep grass, bush. Holcomb (1966) in a study of Redwings in Toledo, Ohio, found them using a great variety of nest sites. 53% were in goldenrod, but others were found in dogwood, blackberry, elm, oak, willow and grapevine. Stowers et al . (1968) report that predominant sites in Florida are small shrubs or grasses in marshy areas or up- land fields. Peek et al . (1972) found that females show a strong attachment to nest site. Brown and Goertz (1978) I found nests in northern Louisiana in 30 species of plants. Agelaius phoeniceus (con't.) g~ Major plants used for nest support were buttonbush, willow, rush, bulrush, cattail, common alder, sweetgum, dock and grasses. Ratios of plant use changed from one habitat to another, as did plant occurrence. Holcomb and Twiest (1968) discuss nest site selection in upland nesting Red- wings in Ohio. E. Special habitat requirements Phillips et al. (1964) say that Redwings are adaptable and where there are no cattails, will nest in willows, mesquite, or elderberry. Francis (1971) reports higher nest success in relatively sturdy shrubs than in herbs and grasses, but species and growth stage have relatively little effect. Height did not seem to be significant in his study. Coccamise (1977) found no relation between nest success and species of shrub used for nesting. Robertson (1972) believes that the commencement of nesting is partially dependent on when vegetation in a particular area becomes suitable. Holcomb and Twiest (1968) found Redwings to adapt to nesting in a variety of habitats. F. Seasonal changes in habitat requirements Meanley (1965) reports that fall roosts are of several m types: (a) those used for short stops by in transit birds; ^^ (b) late summer roosts that continue to be used throughout the fall and sometimes into winter; (c) roosts formed in the fall and used until early spring. V FOOD A. Food preferences Bent (1958) reports they eat alfalfa weevils, pea aphids (Macro siphum pisi) , and peach aphids (Myzus persicae) . Goddard (1969) in a study done in Oklahoma found that 93% of Redwings examined in the fall and winter had eaten grain sorghum, 75% had eaten ragweed, 36% insects, 36% Johnson grass, and lower percentages of about 12 other species. Beasley and Carothers (1974) reported Redwings eating young leopard frogs and pursuing mice but not being able to catch them. Orians (1973) found Redwings eating primarily noctuid larvae in Costa Rica in July. Meanley (1961) found dotted smartweed to make up 38% of the total volume in Redwing stomach sample taken after the breeding season in a fresh water marsh, wild rice 24%. corn 12%, and Walter's Millet 11%. Dolbeer et al. (1978): "Corn (38%) and weed seeds (36%) were the dominant foods for redwings." i t Agelaius phoeniceus (con't.) B. Foraging areas Orians (1973) studied Redwings in Costa Rica that foraged in local marshes and fields. Cattails had few insects and were rarely used as foraging areas. Meanley (1961) did a study on food of Redwings feeding in a fresh water marsh. Dolbeer et al. (1978) found daily foraging areas to vary primarily in response to weather. Redwings were commonly recorded in soybean fields and corn fields. C. Foraging strategies Beasley and Carothers (1974) call Redwings opportunistic generalists able to use several food sources and forage by various means. D. Feeding phenology Orians (1973) reported nestling blackbirds being fed 89.9% spiders, orthopterans, and lepidopteran larvae. Seasonal differences in food fed to young were insignificant. Meanley (1961) noted Red-wings moving into a marsh to feed as the wild rice developed, at the end of the breeding season. During the breeding season they fed more on corn. Dolbeer et al. (1978) recorded increased use of feedlots for feeding as winter progressed. E. Energy requirements Brenner (1966) found mean existence energy requirements to be 24.8 kcal/bird-day. "The existence energy requirements increased from a mean of 25.8 kcal/bird-day at 15 hours of light and 21 C to a mean of 45.5 kcal/bird-day at 9 hours of light and 11 C. The gross energy intake and excrement energy loss also increased as the photo-period and temper- ature decreased. The variation in photoperiod and temper- ature did not influence significantly the efficiency of metabolism by the birds." Orians (1973) reported nestlings being fed at the rate of 1.7 items/nestling/hour in 1966, and 2.2 items/nestling/hour in 1967, in a tropical marsh. Dunson (1965) discusses physiological aspects of the onset of molt. Meanley and Bond (1970; found Redwings in Maryland to undergo their most critical molt period during the time of greatest food availability after breeding. Brenner (1967) discusses fat deposits in Redwings at various times of the year. He found average temperature to affect the breeding cycle, and higher fat deposits present at the beginning of breeding. Agelaius phoeniceus (con't.) VI REPRODUCTION A. Age at first breeding Holcomb (1974a) found brood patches on first year females. Meanley and Bond (1970) believe that first year males usually do not breed and first year females usually do. B. Territorial behavior Peek (1971) says that trespass by conspecific males upon occupied territory reaches a peak in mid-April and then decreases significantly. Territorial males pay little attention to immature males. Muted and epaulet-colored males were unable to maintain territories. Early in the season intraspecific defense is important to achieve spacing of breeding populations, later interspecific defense and protection of female are important. Strosnider (1960) observed a male defending his territory with "song spread", "bill tittling," and attack when necessary. Each female defends a small area around her nest. Nero (1963) describes Yellow-headed Blackbird territorial behavior and compares it with Redwing behavior. Robertson (1972) discusses various aspects of territorial behavior in detail. Nero and Emlen (1951) found territorial boundaries to be sharply defined but not paying particular attention to vegetation or terrain. Males were found to defend their territory against other males, alien females and fledged young. Trespassing by males rarely occurred. Females generally restricted their movements to a fraction of their mate's territory. C. Courtship and mating behavior Goddard and Board (1967) describe courtship as beingning when a female enters a male's territory. Coccamise (1977) "...aggressive interactions between females play an important role in the mating system..." Strosnider (i960) reported a male mated with three females. Nero (1963) compares Redwing behavior with Yellow-headed Blackbird behavior. Orians (1961) mentions that males chase females during courtship. Blakley (1976) suggests that the staggered breeding of females among polygynous Redwings may avoid problems. Younger females are more often polygynous. D. Nesting phenology Goddard and Board (1967) found the first nest in their study area in Oklahoma on 22 April. Redwings are persistent renesters. Orians (1973) noted 6 young already fledged ^ on 6 July, 1966, in Costa Rica. Nest construction had begun m t Agelaius phoeniceus (con't.) on 12 June. There were still some nests under construction on 20 June. Brown and Goertz (1978) found active nests with eggs from 7 April to 2 August in northern Louisiana. Robertson (1972) reported nest activity to begin 17 April in marshes and 8 May in uplands. Young (1963) says that Blackbirds are persistent renesters after failure. Holcomb and Twiest (1968) report nest building to take 3 days. Orians (1961) says territorial defense begins in January in north-central California. In mid-March males begin to feed in the area and by April they spend the bulk of the day in their territories. Faukhauser (1964) found all red- wings at nests with eggs before May 21 that did not raise a brood successfully renested. Three cases of second nesting were found. Dolbeer (1976) in a study done in Ohio found the first eggs laid on 30 April and the last young fledged on 6 August. E. Length of incubation period Holcomb (1974b) - 11 days. Orians (1973) - 11 to 13 days. Brown and Goertz (1978) - 11 to 13 days. F. Length of nestling period k G. Growth rates Holcomb and Twiest (1970) did a detailed study on growth of nestlings. Males grew somewhat faster than females. Sex can generally be determined by weight by day eight. H. Post-breeding behavior Orians (1973) reports Redwings in Costa Rica forming large flocks during the non-breeding season and roosting in dense, herbaceous vegetation. During the last 2 weeks of September the adults were in full molt and during this period terri- torial behavior was reduced to a minimum. During December territorial behavior increased and there was sexual chasing. Orians (1961) says Redwings are highly gregarious in the non-breeding season but that sexes are often segregated. Dolbeer et al. (1978) in a study in Tennessee found redwings to use a post-breeding roost from early November to early March. VII POPULATION PARAMETERS A. Clutch size Bent (1958) - 4 to 5. Peterson (1961) - 3 to 5. Goddard and Board (1967) 1 to 5. Orians (1973) - 2 to 4, with a fc mean of 2.96 in 1966 and 2.67 in 1967. Brown and Goertz W (1978) - 3.82 average, range 3 to 5. Holcomb (1971) dis- cusses the effect of artificial manipulations on clutch size, 10 Agelaius phoeniceus (con't.) B. Fledging success Goddard and Board (1967) found young fledged from 65 of 243 active nests, but they had removed eggs and young from these nests. They had .87 young fledge per early nest and .69 per later nest. Orians (1973) recorded fledging success for 18 nests in a tropical marsh: 13 fledged 3, 3 fledged 2, and 2 nests fledged 1 each. In 1967 only 20 out of 93 nests fledged any young. Brown and Goertz (1978) reported 2.77 young fledged per nest from 65 successful nests over an eight-year period. Dolbeer (1976) reported 5.5 young fledged per territory and 13.3 per hectare annually. Knox and Stickley (1974) discuss hand rearing of Redwings. C. Mortality rates per age class Goddard and Board (1967) say that early nests tend to be more successful than nests started after 1 June. Many of the nests initiated after this were renesting. Holcomb (1966), "Young (1963) found that mortality. .. is greatest in nestlings. Nestlings begin crowding each other at 8-11 days of age..." and some are crowded out of the nest. "One factor influencing age specific mortality in nestlings may be their ability to grasp and balance. Robertson (1972) found morta- lity rates in nestlings to be uniform up to day 19, when they dropped significantly. Starvation was the single factor most responsible for mortality of nestlings. Young (1963) discusses causes of egg and nestling mortality. Most eggs and young were lost to predation. Faukhouser (1967) did a study of band returns and found approximately 50% survival per year. Coccamise (1976) found that nestling mortality increased with age. D. Longevity Kennard (1975) found the oldest banded Redwing to be 14 years, 5 months. E. Seasonal abundance Meanley (1961) reports thousands of Redwings invading a tidal marsh immediately after the breeding season. Meanley (1964): "As the redwings approach the completion of molt in the latter half of September, they begin to move toward the wintering grounds," dispersing over a wide area. F. Habitat density figures Robertson (1972) believes that habitat density is kept at low levels due to territoriality. Density was 10 times higher in marsh than in upland habitat in his study. Whitmore (1977) discusses habitat partitioning of redwings and other passerines. 11 t Agelaius phoeniceus (con't.) Ill INTERSPECIFIC INTERACTIONS A. Predation Orians (1973) reported 47 young taken during 524 potential nestling days in a tropical marsh. Snakes were seen taking young but he believes that few are taken by avian predators. Robertson (1972) did a study comparing nesting success in upland vs. marsh habitat and found less predation in marshes, but that predation was the most common cause of nest failure. Young (1963) found the most common loss of eggs and young to be predation. Coccamise (1976) gives a detailed discus- sion of predation. He found predation while the prime cause of mortality was less in more dispersed nests. B. Competition Bent (1958) does not discuss competition but tells of Red- wings attacking ravens, magpies and even sparrows. Goddard (1969) reported Redwings eating grain sorghum in large quantities and damgaing farmer s crops. The Redwings com- peted with ducks for sorghum. Burtt and Giltz (1977) report that starlings, grackles, Redwings and Brown-headed Cowbirds roost together in the non-breeding season. C. Parasitism Friedmann et al. (1977) report most records of parasitism by the cowbird are from the central U.S. and Canada. 2.3% of the Red-wing clutches in the Western Foundation of Verte- brate Zool. are parasitized. Brown and Goertz (1978) found 12 of 755 nests parasitized by the Brown-headed Cowbird. IX STATUS A. Past population trends B. Present population status Goddard and Board (1967) attribute the upward trend in the number of Red-winged Blackbirds nesting in Oklahoma to the increased number of farm ponds and flood dams. C. Population limiting factors D. Environmental quality: adverse impacts Graber et al. (1965) discuss the adverse impact on nesting Redwings in a field sprayed with dieldrin. Dolbeer et al . (1978) found Redwings to have little impact on agricultural k crops. Tanner and Tolbert (1975) discuss the effect of f chlorinated hydrocarbons on Redwing eggshells. E. Potential for endangered status 12 Agelaius phoeniceus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Beasley, L. E. and S. W. Carothers. 1974. Unusual feeding habits in two species of blackbirds. Wil. Bull. 86:478-479. Bent, A. C. 1958.. Life histories of North American black- birds, orioles, tanagers and their allies. Smithsonian Institution. U.S. Nat. Mus. Bui. No. 211. Washington. Blakely, N. R. 1976. Successive polygyny in upland nesting Red-winged Blackbirds. Condor 78:129-133. Brenner, F. J. 1966. Energy and nutrient requirements of the Red-winged Blackbird. Wil. Bui. 78:111-120. Brenner, F. J. 1967. Seasonal correlations of reserve energy of Red-winged Blackbird. Bird-Banding 38:195-211. Brenner, F. J. and W. F. Malin. 1965. Metabolism and survival time of the Red-winged Blackbird population. Wil. Bui. 77:282-289. Brown, B. T. and J. W. Goertz. 1978. Reproduction and nest site selection by Red-winged blackbirds in north Louisiana. Wil. Bui. 90:261-270. Burtt, H. E. and M. L. Giltz. 1977. Seasonal directional patterns of movements and migrations of Starlings and black- birds in North America. Bird-Banding 48:259-271. Coccamise, D. F. 1976. Nesting mortality in the Red-winged Blackbird. Auk 93:517-534. Coccamise, D. F. 1977. Breeding success and nest site character- istics of the Red-winged Blackbird. Wil. Bui. 89:396-403. Davis, D. E. 1972. Stability of a population of male Red-winged Blackbirds. Wil. Bui. 84:349-350. Dawson, W. L. 1923. The birds of California. Vol. 1. South Moulton Co., San Francisco. Dolbeer, R. A. 1976. Reproductive rate and temporal spacing of nesting of Red-winged Blackbirds in upland habitat. Auk 93:343-355. 13 Agelaius phoeniceus (con't.) Dolbeer, R. A., P. P. Woronecki, A. R. Stickley and S. B. White. 1978. Agricultural impact of a winter population of black- birds and starlings. Wil. Bui. 90:31-44. Dunson, W. A. 1965. Physiological aspects of the onset of molt in the Red-winged Blackbird. Condor 67:265-269. Faukhauser, D. P. 1964. Renesting and second nesting of individually marked Red-winged Blackbirds. Bird-Banding 35:119-121. Faukhauser, D. P. 1967. Survival rates in Red-winged Black- birds. Bird-Banding 38:139-142. Francis, W. J. 1971. An evaluation of reported reproductive success in Red-winged Blackbirds. Wil. Bui. 83:178-185. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the para- sitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Goddard, S. V. 1969. Fall and winter food habits of Red-winged Blackbirds and Brown-headed Cowbirds in western Oklahoma. Wil. Bui. 81:336-337. Goddard, S. V. and V. V. Board. 1967. Reproductive success of Red-winged Blackbirds in north-central Oklahoma. Wil. Bui. 79:283-289. Grabar, R. R. , S. L. Wunderle and W. N. Bruce. 1965. Effects of a low-level dieldrin application on a Red-winged Black- bird population. Wil. Bui. 77:168-174. Grinnell, J. 1915. A distributional list of the birds of California. Pacific Coast Avifauna. No. 11, 217 pp. Grinnell, J. 1928. A distributional summation of the ornithology of lower California. Univ. of Calif., Berkeley. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna. No. 27. 608 pp. Helms, C. W. 1962. Red-winged Blackbird killing a Sharp- tailed Sparrow. Wil. Bui. 74:89-90. Holcomb, L. C. 1966. Red-winged Blackbird nestling development. Wil. Bull. 78:283-288. Holcomb, L. C. 1971. Nest building and egg-laying by Red-winged Blackbirds in response to artificial manipulations. Auk 88:30-34. 14 Agelaius phoeniceus (con't.) Holcomb, L. C. and G. Twiest. 1968. Ecological factors affect- ing nest building in Red-winged Blackbirds. Bird-Banding 39:14-22. Holcomb, L. C. and G. Twiest. 1970. Growth rates and sex ratios of Red-winged Blackbirds nestlings. Wil. Bui. 82: 294-303. Holcomb, L. C. 1974a. The question of possible surplus females in breeding Red-winged Blackbirds. Wil. Bui. 86:177-179. Holcomb, L. C. 1974b. Incubation constancy in the Red-winged Blackbird. Wil. Bui. 86:450-460. Kennard, J. H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. Knox, C. J. and A. R. Stickley. 1974. Breeding Red-winged Blackbirds in captivity. Auk 91:808-816. Knowlton, F. H. 1909. Birds of the World. Henry Holt & Co., New York. 873 pp. Mayr, E. and L. Short. 1970. Species taxa of North American birds. Publication of the Nuttal Ornithological Club, No. 9. Cambridge. Meanley, B. 1961. Late-summer food of Red-winged Blackbirds in a fresh tidal-river marsh. Wil. Bui. 73:36-40. Meanley, B. 1964. Origin, structure, molt, and dispersal of a late summer Red- winged Blackbird population. Bird-Banding 35:32-38. Meanley, B. 1965. The roosting behavior of the Red-winged Blackbird in the southern United States. Wil. Bui. 77: 217-228. Meanley, B. and G. M. Bond. 1970. Molts and plumages of the Red-winged Blackbird with particular reference to fall migration. Bird-Banding 41:22-27. Nero, R. W. 1963. Comparative behavior of Yellow-headed Black- bird, Red-winged Blackbird and other Icterids. Wil. Bui. 75:376-413. Nero, R. W. and J. T. Emlen, Jr. 1951. An experimental study of territorial behavior in breeding Red-winged Blackbirds. Condor 53:105-116. Orians, G. H. 1961. The ecology of blackbird (Agelaius) social ■ systems. Ecol. Monog. 31:285-312. ^ 15 Agelaius phoeniceus (con't.) Orians, G. H. 1973. The Red-winged Blackbird in Tropical marshes. Condor 75:28-42. Peek, F. W. 1971. Seasonal change in the breeding behavior of the male Red-winged Blackbird. Wil. Bui. 83:383-395. Peek, F. W. , E. Franks and D. Case. 1972. Recognition of nest, eggs, nest site, and young in female Red-winged Blackbirds. Wil. Bui. 84:243-249. Peterson, R. T. 1961. A field guide to western birds. 2nd Edition. Houghton Mifflin Co., Boston, 366 pp. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. of Ariz. Press, Tucson. 212 pp. Rand, A. L. 1961. Some size gradients in North American birds. Wil. Bui. 73:46-56. Ridgway, R. 1915. A manual of North American birds. Fourth Edition. J. B. Lippincott Company, Philadelphia. 653 pp. Robbins, C. S., B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Robertson, R. J. 1972. Optimal niche space of Red-winged Blackbird (Agelaius phoeniceus). I. Nesting success in marsh and upland habitat. Canadian Jour. Zool. 50:247-263. Rogers, J. G. , Jr. 1978. Some characteristics of conditioned aversion in Red-winged Blackbirds. Auk 95:362-369. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Stowers, J. F. , D. T. Harke and A. R. Stickley, Jr. 1968. Vegetation used for nesting by the Red-winged Blackbird in Florida. Wil. Bui. 80:320-324. Strosnider, R. 1960. Polygyny and other notes on the Red- winged Blackbird. Wil. Bui. 72:200. Tanner, J. T. and W. W. Tolbert. 1975. Optical and gamma radiation measurements of the effects of chlorinated hydrocarbons on egg shells of Red-winged Blackbirds. Wil. Bui. 87:426-427. Weatherhead, P. J. and R. J. Robertson. 1977. Male behavior and female recruitment in the Red-winged Blackbird. Wil. Bui. 89:583-592. Wetherbee, D. K. 1962. Breeding of Red-winged Blackbird in captivity. Wil. Bui. 74:90. 16 Agelaius phoeniceus (con*t.) Whitmore, R. C. 1977 . Habitat partitioning in a community of passerine birds. Wil. Bui. 89:253-265. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. Young, H. 1963. Age-specific mortality in the eggs and nestlings of blackbirds. Auk 80:145-155. < 4 I • % RUBY-CROWNED KINGLET Regulus calendula I TAXONOMY A. Type description AOU (1957) Regulus calendula cineraceus Grinnell, Condor, 6 , No . 1 , Jan7~T5~j 1904, p. 2*5"! (Strain ' s Camp , Mount Wilson, Los Angeles County, California.) B. Current systematic treatments AOU (1957) considers the Ruby-crowned Kinglet a member of the Order Passeriformes, Family Sylviidae, Subgenus Corthylio, with 4 subspecies. Dawson (1922): "There are probably few problems more fascinating or difficult than the distribution of the races of Corthylio calendula [R. calendula"] and the key to a solution lies in a study of "the songs " C. Synonomies of scientific nomenclature Grinnell and Miller (1944) - Regulus calendula calendula, Corthylio calendula cineraceus, Corthylio c. calendula. Baird (1905), referring to R. calendula - Motacilla calendula. D. Synonomies of vernacular nomenclature Dawson (1923) - Ashy Kinglet. Grinnell and Miller (1944) Ruby-crowned Wren, Ruby-crowned Kinglet, Ashy Kinglet, Eastern Ruby-crowned Kinglet. II DESCRIPTION A. External morphology of adults Peterson (1961)' "Note the conspicuous broken white eye-ring, which gives the bird a big-eyed appearance. A tiny birdlet, olive-gray above, with 2 pale wing-bars; male with a scarlet crown patch (erected when excited). Occasional males have yellow crowns." Dawson (1923): "Similar to Corthylio (Regulus) calendula calendula, but larger and much less olivaceous; the color tone of the foreparts ashy or grayish olive, decided olive- green often not appearing above the middle of the back; probably also without increase of olivaceous in fall and winter. Bairdet al. (1905), describing R. calendula: "Above dark greenish olive, passing into bright olive-green on the rump and outer edges of the wings and tail. The underparts are Regulus calendula (con't.) grayish-white tinged with pale olive-yellow, especially behind. A ring around the eye, two bands on the wing coverts, and the exterior of the inner tertials white. Male. Crown with a large concealed patch of scarlet feathers, which are white at the base. Female without red on the crown." Ridgway (1915): "Above grayish olive, the head not darker than back; adult male with crown-patch bright medium-red, or scarlet-vermillion. Length 3.75-4.60, wing 2.20-2.30, tail 1.85-1.90, bill from nostril .20-. 22, tarsus .75." B. External morphology of subadult age classes Baird et al. (1905) referring to R. calendula: "Young without red on the crown." C. Distinguishing characteristics Interspecific - Peterson (1961): "Any kinglet not having a conspicuous crown patch is of this species. The stubbier tail distinguishes it from any of our warblers, as does the dark bar bordering the rear wing-bar. Similar species: Golden-crowned kinglet and Hutton's Viero." Robbins et al . (1966): "Told from the Golden-crown by eye-ring and from vireos or fall warblers by its smaller size, short tail, and habit of flicking its wings." Intraspecific - Dawson (1923): "Similar to R. c. calendula but larger and much less olivaceous." Jewett et al . (1953) says grinnelli is similar to cineraceus but smaller and darker. Godfrey (1966) says cineraceus is grayer and paler than calendula. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species A0U (1957), R. calendula cineraceus: "Breeds from south- central British Columbia (probably the mountains of south- western Alberta) and western Montana southward in the moun- tains to southern California (to Mount Pinos, and the San Gabriel, San Bernardino, San Jacinto, and White Mountains), central and southern Arizona, east-central Colorado, and central New Mexico." Oberholser (1974) gives the distribution in Texas as: "Taken north to Haskell (May 15) east to Travis and Victoria (May 5), south to Hidalgo, west to Brewster and Culberson Counties." Gullion (1959) says that R. calendula is an uncommon winter visitor in Nevada in the brusHy areas, arriving as early as 26 September and remaining as late as 28 April. Hines (1963) reports Ruby-crowns as a common m resident of the Alaskan spruce forest. Jewett et al . (1953) Q Regulus calendula (con't.) say that Ruby-crowns are a permanent resident of Washington state, principally east of the Cascade Mountains, wandering to western Washington during migration. Sutton (1967) notes that Ruby-crowns do not nest in Oklahoma, but do migrate through. Gabrielson and Jewett (1940) note than cineraceus breeds from the Cascade Mountains and Blue Mountains of Oregon south to southern California. B. California distribution of the species Grinnell and Miller (1944), for R. calendula cineraceus: "As breeding, Siskiyou, Trinity, and~Warner mountains m north thence south in Cascade Mountains and Sierra Nevada from Mount Shasta to southern Tulare County; in southern California, on Mount Pinos, San Gabriel, San Bernardino and San Jacinto Mountains." Dawson (1923): "Common breeder in the Boreal Zone from the Warner and Siskiyou Mountains south along the central Sierras to about Long Meadow in Tulare County (Grin- nell); also in the San Bernardino and San Jacinto Mountains. Common in winter at the lower levels, especially southerly and southeasterly. Stewart et al. (1974; do not mention R. calendula in this paper on inland and coastal fall migra- ting passerines in central California. C. California desert distribution Grinnell and Miller (1944) give breeding records from these sites; San Bernardino and San Jacinto Mountains, Mohave and Colorado deserts east to Colorado River and from Death Valley south to Mexican line, Kern County, San Bernardino County, San Diego County. Willett (1951) lists R. c. cineraceus as a winter resident only, in the southern (California desert. D. Seasonal variation in distribution AOU (1957): "Winters from southern British Columbia, Idaho, Nevada, and southern Utah, south to Baja California and the highlands of northern Mexico." Grinnell and Miller (1944): "Winter visitant in western lowlands and on southeastern deserts from late September to mid-April. In winter wide tolerance of conditions is shown." Sutton (1967) says Ruby-crowns are found in Oklahoma during migration, pri- marily from mid-September to 1 December and from mid-March to 6 May. IV HABITAT A. Biotopic affinities Peterson (1961): "Conifer forests; in winter other woodlands, thickets. Grinnell and Miller (1944): "In breeding season coniferous forests either of moderately dense type or where Regulus calendula (con't.) trees are open and broken. Robbins et al. (1966): "Prefers conifers." Godfrey (1966): "In nesting season, coniferous forests and woodlands, muskegs, also mixed woods." Sutton (1967) says that during the Ruby-crown's migration through Oklahoma they inhabit all kinds of woods, showing no pre- ference for evergreens. B. Altitudinal range Grinnell and Miller (1944): "Extreme altitudes of nesting range from 1500 feet to 10,000 feet." C. Home range size D. Territory requirements Perch sites Courtship and mating sites Nest sites - Grinnell and Miller (1944) say they nest in concealing needle tufts at middle heights in lodgpole pines, mountain hemlock and firs. Godfrey (1966): "In coniferous trees at almost any height but most often well up." E. Special habitat requirements F. Seasonal changes in habitat requirements Godfrey (1966) says that during migration they are found in all kinds of woodland; also in thickets of tall shrubs such as alder and willow. V FOOD A. Food preferences Baird et al. (1905) says they eat chiefly insects, but also eat the stamens of blossoms of trees. Robertson (1959) had Ruby-crowns feeding at his hummingbird feeder. Hespen- heide (1962) give a description of Ruby-crowns feeding on insects caught in the cracks of buildings. B. Foraging areas Grinnell and Miller (1944) say they forage in the terminal foliage. IP i • Regulus calendula (con't.) C. Foraging strategies Baird et al. (1905) report them to be very active in the pursuit of insects. Jewett et al. (1953) say they spend most of their waking hours searching the foliage for insects. They often make flycatcher-like excursions into the air, snapping their beak and returning to their perch. D. Feeding Phenology Baird et al . (1905): "They are chiefly met in the spring among the tree tops, where the insects they prefer abound... In the fall of the year... they are more commonly met among lower branches, and among bushes near the ground." E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior j* C. Courtship and mating behavior D. Nesting phenology Dawson (1923) just gives "June" as the season. E. Length of incubation period F. Length of nestling period G. Growth rates H. Post-breeding behavior VII POPULATION PARAMETERS A. Clutch size Peterson (1961) - 6 to 9. Dawson (1923) - 5 to 9 . Godfrey (1966) - 5 to 11. Sutton (1967) - as many as 11. B. Fledging success C. Mortality rates per age class D. Longevity Kennard (1975) did not find any banding records indicating the banded Ruby-crowns live longer than four years. 6 Regulus calendula (con't.) E. Seasonal abundance F. Habitat density figures III INTERSPECIFIC INTERACTIONS A. Predation Gabriel son and Jewett (1940) publish an account of a Rocky- Mountain Jay taking eggs from a Western Ruby-crowned Kinglet nest in Oregon. B. Competition C. Parasitism Friedmann et al . (1977): "In spite of its diminutive size, the Ruby-crowned Kinglet must be rated as a regular. . .host choice of the Brown-headed Cowbird." IX STATUS A. Past population trends B. Present population status Grinnell (1933): "Common summer visitant to the Canadian zone from Warner and Siskiyou Mountains along Sierra Nevada south to Tulare County. Also sparingly in southern Calif- ornia on San Gabriel Mountains, San Bernardino Mountains and San Jacinto Mountains." C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status I Regulus calendula (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Baird, S. F. , T. M. Brewer and R. Ridgway. 1905. A history of North American birds. Vol. 1. Little, Brown and Co., Boston. Carter, F. 1939. How does the Ruby-crowned Kinglet's Crown work? Condor 41:79. Dawson, W. L. 1923. The birds of California. Vol. 2. South Moulton Co., Los Angeles. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the para- sitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Gabrielson, I. N. and S. G. Jewett. 1940. Birds of Oregon. Oregon State College, Corvallis. 650 pp. Godfrey, W. E. 1966. The birds of Canada. National Museum of Canada, Bull. no. 203. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna. No. 27. 608 pp. Gullion, G. W. , W. M. Pulich and F. G. Evenden. 1959. Notes on the occurrence of birds in southern Nevada. Condor 61: 278-297. Hespenheide, H. A. 1962. Adaptive feeding in a Ruby-crowned Kinglet. Wil. Bull. 74:93-94. Hines, J. Q. 1963. Birds of Noatak River, Alaska. Condor 65:410-425. Jewett, S. G., W. P. Taylor, W. T. Shaw and J. W. Aldrich. 1953. Birds of Washington State. Univ. of Washington Press, Seattle. 765 pp. Kennard, J. H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. Knowlton, F. H. 1909. Birds of the world. Henry Holt and Co., New York. 873 pp. Leberman, R. C. 1970. Pattern and timing of skull pneumatiza- tion in the Ruby-crowned Kinglet. Bird-banding 41:121-124. 8 Regulus calendula (con't.) Oberholser, H. C. 1974. The bird life of Texas. Vol. 2. Univ. of Texas Press, Austin. Peterson, R. T. 1961. A field guide to western birds. Houghton Mifflin Co., Boston. 366 pp. Ridgway, R. 1915. A manual of North American birds. Fourth Edition. J. B. Lippincott Company. 653 pp. Robbins, C. S., B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Robertson, J. McB. 1959. Ruby-crowned Kinglet feeding on nectar. Condor 61:371. Stewart, Robert M. , L. Richard Mewaldt and Susan Kaiser. 1974. Age ratios of coastal and inland fall migrant passerines in central California. Bird-Banding 45:46-57. Sutton, G. M. 1967. Oklahoma birds. Univ. of Oklahoma Press, Norman. 674 pp. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna. No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. I RUFOUS- SIDED TOWHEE Pipilo erythrophthalmus I TAXONOMY A. Type description AOU (1957), P. e. montanus : Pipilo maculatus montanus Swarth, Condor, 7, no. 6, Nov. 22, 1905, p. ITT. (Miller Canyon, Huachuca Mountains, Arizona.) P. e. curtatus : Pipilo maculatus curtatus Grinnell, Univ. California Publ. Zool. , 7, no. 8, Aug. 24, 1911, p. 309. (Big Creek Ranch, alt. 4350 feet, base of Pine Forest Mountains, Humboldt County, Nevada.) P. e. megalonyx: Pipilo megalonyx Baird, in Baird, Cassin, and Lawrence, Rept. Expl~ and Surv. R. R. Pac. , vol. 9, 1858 pp. XLI, 511, 515. (Fort Tejon, California] . ) B. Current systematic treatments Swarth (1913), for historical importance, a treatment of the California forms of the species, at that time recog- nizing (megalonyx, falcif er, falcinellus, curtatus, clementae) . Paynter (1970), recognizes seven species in the genus Pipilo; twenty- four subspecies in the species erythrophthalmus . Passeriformes: Emberizidae (Emberizinae) . C. Synonomies of scientific nomenclature P. e. megalonyx: Dawson (1923) - P. maculatus megalonyx. Grinnell and Miller (1944), FringTlla arctica; P. arcticus ; P. macutatus atratus. P. e. curtatus : Dawson (1923) - P. maculatus curtatus . Grinnell and Miller (1944), P. m. falcinellus. P. e. montanus: Dawson (1923) - _P. maculatus montanus . D. Synonomies of vernacular nomenclature P. e. megalonyx: Dawson (1923) - Spurred Towhee; San Diego Spotted Townee. Grinnell and Miller (1944), Arctic Ground Finch; California Ground Robin; Southern Pipilo; California Finch; Long- spurred Towhee. P. e. curtatus : Dawson (1923) - Spurred Towhee; Mountain Townee; Nevada Spotted Towhee. Grinnell and Miller (1944), Long-clawed Towhee Bunting; Long- spurred Towhee, Sacramento Towhee; Nevada Towhee. Pipilo e ry throphthalmus (con't.) P. e_;_ montanus : Dawson (1923) - Arizona Spotted Towhee; Mountain Towhee . II DESCRIPTION A. External morphology of adults Dawson (1923), P. e. megalonyx: "Adult in spring and summer: Head and neck all around and breast glossy black, the black of remaining underparts dulling posteriorly, especially upon rump and remiges; the scapulars heavily marked with longitudinal spots of white, included or else occupying entire outer web of feathers. . .Outer pair of rectrices narrowly margined and broadly tipped with white. . .Underparts centrally pure white, the sides and flanks tawny. .. Irides red; bill black; feet and tarsi dark brown. Fall and winter specimens have feathers of upperparts slightly washed or tipped with pale tawny, especially upon rump. Female in spring: Similar to male, but duller, the black veiled with olivaceous gray, the ground color strongest on throat and chest and persisting centrally on pileum and notaeum; the white tips of scapulars, rectrices, etc., more restricted, the tibia dusky." P. e. curtatus : "Similar to P. m. (e.) me gal onyx, but black o"F upperparts less pure, grayer; white markings notably increased and carried clear across the I m back; tawny of sides, etc., paler and more restricted, apical white spots of 3rd pair of rectrices more extended; hind claw notably weaker." P. e. montanus : "Similar to P. m. (e.) me gal onyx, but paler every way; back and rump witE admixture of gray; white markings more extended and diffuse; apical spotting of tail more extended; hind claw weaker." Ridgway (1901), P. maculatus megalonyx: detailed description of adult males and females, including plumage, soft parts, and measurements. Peterson (1961), Male: head and upper parts black; rows of white spots on back and wings; sides robin-red; belly white. Flashes large white spots in tail corners. Female: Similar, but dusky brown where male is black." B. External morphology of subadult age classes Dawson (1923), P. e. megalonyx: "highly streaked appearance, not unsuggestive oT a female Redwing (Agelaius phoeniceus) : Upperparts blackish, margined with cinnamon- buf f . . .white spotting of adult much restricted; underparts mingled blackish, whitish, and cinnamon-buff .. .Throat, chest, and sides of breast finely streaked." Peterson (1961), "in summer are streaked below like large slender sparrows but have the tail pattern of this towhee." Baumann (1959), detailed descrip- tion of skin, other soft parts, and extent of down from ^ day 1 to day 8. « ifc Pipilo erythrophthalmus (con't.) C. Distinguishing characteristics Interspecific - Peterson (1961), "smaller and more slender than Robin. " Intraspecific - Dawson (1923), "As compared with the easterly races of maculatus , megalonyx shows clearer black upon the back and restriction or white spotting." Borror (1975), analysis of the nature and amount of geographical variation in the local repetories of the subspecies occurring in the U.S. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) P. erythrophthalmus in general: "Southern British Columbia, central Alberta, central Saskatchewan, southern Manitoba, northern Minnesota, northern Michigan, southern Ontario, northern New York, northern Vermont, central New Hampshire, and southwestern Maine south to southern Baja California through Mexico to Guatemala, and western Texas, northern Oklahoma, northern Arkansas, central southern Louisiana, the eastern Gulf coast, and southern Florida... Fossil, in the late Pleistocene of California." P. e. montanus : "Breeds from central eastern California "(Benton) , southern and central eastern Nevada (Grapevine Mountains, Lehman Creek), northern Utah (Stansbury Island, Uinta Mountains), and northwestern and central northern Colorado (Boulder) south to southeastern California (Provi- dence Mountains), central western and central southern Arizona (Harquahala Mountains, Baboquivari Mountains), northeastern Sonora (San Jose and San Luis Mountains), northwestern Chihuahua (Sierra Madre, south to lat. 29°N.), and central southern and northeastern New Mexico (Mesilla Park, Sierra Grande) .. .Casual in Nebraska (North Platte) and Kansas (Morton County), and accidental in New Jersey (Metuchan)." P. e. curtatus: "Breeds from central southern British Columbia (Lilloet, Okanagan Landing, Robson) and northern Idaho (5 miles west of Cocolalla) south, east of the Cascades, to northeastern California (south to Mono Lake), western and central Nevada (Tybo), and southeastern Idaho (Craters of the Moon)." P. e. megalonyx: "Resident in southwestern California (Monterey and west slope of Walkers Pass south to Santa Cruz Island, Little San Bernardino Mountains, and San Diego County) and northwestern Baja California (south to about lat. 32° N.). Casual on San Miguel Island, Calif- ornia. " Pipilo erythrophthalmus ( con ' t . ) B. California distribution of the species Dawson (1923), P. e. mega 1 onyx: "Resident in the Pacific Coast district of southern California and northern Lower California, north along coast to San Luis Obispo County, east to southern Sierras (northern Kern County) . Also Santa Cruz Island and... Santa Rosa." P. _e. curtatus : " "northeastern California. . .breeds in tEe Warner Mountains of Modoc County." P. e. montanus : "Known only from the Panamint Mountains Tn Inyo County, where breeding." Grinnell and Miller (1944), P. e. curtatus : "breeding, northeastern section from Oregon line south to Mono Lake; limited to westward by high-zone forests of Cascade- Sierran system." P. e. montanus : "Mountain ranges of Inyo district from south- eastern Mono County south to northern San Bernardino County and from east side of Owens Valley to Nevada line." P. e. megalonyx: "Coastal districts from Monterey County west of lower (northern) Salinas Valley south to Mexican boundary; interiorly, from Kern County, southward, Included are the Kern River basin northeast to Walker Pass and the interior coast ranges north to extreme western Fresno County. Occurs also on Santa Rosa and Santa Cruz islands. Intergradation with adjoining races to the northward is notably gradual." C. California desert distribution Dawson (1923), P. e. montanus : "south of the Great Basin to the desert ranges of eastern California, ... Panamint Mountains, Inyo County, where breeding." Small (1974), "absent only from higher mountain areas and southeastern deserts." Grinnell and Miller (1944), P. _e. curtatus: reported in Potholes, Imperial County. P. e. megalonyx: reported at Pasadena, Los Angeles County; San Bernardino, San Bernar- dino County; Escondido, San Diego County; Palm Springs, Riverside County. Cardiff (1956), reported P. m. megalonyx collected on the New River northwest of Westmoreland. Willett (1912), reports two fresh eggs of P. e. megalonyx near Claremont, Los Angeles County. Miller (1951), P« e. me gal onyx: Kern Basin and San Diego. P. e. curtatus: Modoc ana Inyo regions. P. e. montanus : Inyo and Mojave regions. D. Seasonal variations in distribution AOU (1957), P. erythophthalmus in general: "Winters from southern British Columbia, Utah, Colorado, Nebraska, Iowa, the southern Great Lakes area, and Massachusetts southward." P. e. montanus : "Winters from southern Utah (Beaverdam Mountains) , central Colorado (Golden), and western Texas (Palo Duro Canyon) south to northern Sonora (Sierra Carrizal, Nacozari) , central Chihuahua (Chihuahua), and central Texas (Del Rio; Kendall County); casually farther southeast in Pipilo erythrophthalmus (con't.) Texas (Victoria, Eagle Lake)." P. e. curtatus : "Winters in part in breeding range and south to southeastern Calif- ornia (Potholes), northwestern Sonora (Sonoyta), and south- eastern Arizona (Huachuca and Chiricahua Mountains)." Peterson (1961), winters mainly from S. B. C. , Utah, Colorado south." Grinnell and Miller (1944), P. e. curtatus: "Summer resident in Great Basin region "From late March to early October; partly migratory, some birds winter- ing far to southward in State." IV HABITAT A. Biotopic affinities Small (1974), "chaparral and forest undergrowth, riparian thickets." Peterson (1961), "brush, chaparral, undergrowth, forest edges, city shrubs." Grinnell and Miller (1944), P. e. curtatus : "Basic requirements much as in race montanus . . .^rush cover inhabited includes willow thickets, artemisia and rabbit brush. In winter, in Colorado River valley, occurs in thickets of arrowweed and in atriplex bushes. P. e. montanus: "Large, stiff -branched shrubs, particularly Tn bottoms of ravines and canyons and along bases of rock outcrops. . .Purshia, willow thickets and tall artemisia bushes commonly provide the necessary cover." P. e. megalonyx: "Principally river bottom thickets and cEaparral. Tangles of blackberry, wild grape, willow thickets, poison oak, scrub oak, ceanothus and manzanita are prominent plant associates, but any brush cover appears to serve if it is fairly tall and produces abundant leaf litter either by reason of the plant types involved or because of favorable topography of the ground beneath." Miller (1951), Upper and Lower Sonoran and Transition life zones. B. Altitudinal range Grinnell and Miller (1944), P. e. curtatus: "from 4000 feet in Honey Lake Valley, Lassen County up to 8000 feet on Warner Mountains." P. e. montanus : "4300 feet to 8000 feet; may wander up to 10,U00 feet in late summer." P. e. megalonyx: "from near sea level, as at Laguna Beach, up to 70U0 feet in San Bernardino Mountains ; late summer vagrants range up to 9000 feet." C. Home range size D. Territory requirements Perch sites - Grinnell and Miller (1944), P. e. montanus: "pinons, junipers or mountain mahoganies wKicn" afford exposed elevated song posts essential for the males." Davis (1958) Pipilo erythrophthalmus (con't.) "highly variable. . .may sing from the ground while foraging or from as high as 50 feet up in tall trees. By far the greatest number of singing perches noted were in trees, especially in live and valley oaks, but to some extent in willows and sycamores. . .May sing from exposed perches, such as bare limbs or the tops of trees or shrubs, but usually they sing from leafy cover where they are at least partly concealed." Courtship and mating sites - Baumann (1959) "After singing in one place for a while, the birds often flew to a different location, sang there for a period of time, and then passed to another site. In this way they regularly covered most of their territory (courtship and territorial singing by males)." Nest sites - Dawson (1923), "Placed on the ground, or, rarely, very low in bushes, and usually sunk deeply in loose leaf- waste or trash; composed of grasses, barkstrips, dried leaves, lined with fine grasses." Davis (1960), "Since nests were flush with the ground, or nearly so, surrounding vegetation. . .provided sufficient lateral screening." Baumann (1959;, "generally. . .on the ground." E. Special habitat requirements Grinnell and Miller (1944), "For desert areas, the brush required is relatively dense and tall... Only in such brush is deep leaf litter likely to accumulate, protected from wind scattering, where these towhees can forage." F. Seasonal changes in habitat requirements V FOOD A. Food preferences Dawson (1923) "insects. .. fallen seeds." Davis (1960) re- ports adults feeding insect larvae to nestlings. Graskin (1950), stomach contents included ants. B. Foraging areas Grinnell and Miller (1944), "Although foraging is chiefly on the ground, in summer and fall berries are taken from bush tops." Woodbury (1933), "If the visible food supply on the surface is not sufficient for its needs, the towhee takes to turning over the leaves and scratching among the trash with its feet." Davis (1957a), "sheltered soil cover in which the birds may find their food by scratching. . . Rarely forage in areas which are not screened from above by - overhanging vegetation, and even more rarely do they search ^ for food in bare or sparsely covered soil." » |fc Pipilo erythrophthalmus (con't.) C. Foraging strategies Dawson (1923), "scratching for food... by a succession of backward kicks, executed. . .by both feet at once, and assisted by a compensatory flash of the wings." Woodbury (1933) describes bilateral scratching behavior used when foraging. Davis (1957a), "involve gleaning exposed food items, mainly weed seeds and insects, from the soil surface or obtaining food located by scratching in soil cover or in the upper layers of exposed soil... The nature of foraging, whether predominantly by scratching or by pecking at the surface, is determined by the nature of the terrain traversed." Includes a detailed discussion of comparative foraging with the Brown Towhee; foraging behavior, osteology and myology of the hind limbs, methods of locomotion and foraging. D. Feeding phenology Davis (1960), "nestlings in early nests are fed mainly larvae, whereas nestlings in later nests are fed mainly grasshoppers, the shift coinciding with the relatively greater abundance of larvae in the spring and the relatively greater abundance of grasshoppers in the early summer." Davis (1961), "The short bill and long intestinal tract of birds taken in winter apparently correlate with the vegetable diet utilized at that season; the long bill and short intestinal tract of birds taken in summer apparently correlate with increased consumption of insect material in the summer period." Davis (1957a), "ate cof f eeberries (Rhamnus calif ornica) between August 22 and December 24. . .The preponderance of September records. .. suggests that cof f eeberries are also an important source of water during this hot, dry month." E. Energy requirements VI REPRODUCTION A. Age at first breeding Davis (1958), "Throughout the period of spermatogenesis there is a definite tendency for adults to precede first year birds in the attainment of (first primary spermatocytes in synapsis, predominance of primary spermatocytes in synapsis, first spermatids, breeding)." B. Territorial behavior Bauman (1959), "From fall until late winter there seemed to be no evidence of territorality. . .However, in February, the males began to sing vigorously in a given area, and to spend more of their time there. Foreign males were chased away, but paired or unpaired females were not disturbed. . . Males maintained their territories from the time pairing began to the end of the breeding season. C. Courtship and mating behavior g*^ Davis (1958) detailed discussion of singing behavior with respect to breeding season. Baumann (1959;, "after pair- ing takes place, the song of the male becomes less frequent and insistent than the calls and songs of the unpaired males. " D. Nesting phenology Dawson (1923), "Season: May, June; one or two broods." Davis (1960), "at Hastings Reservation in coastal Calif- ornia occurs between about April 20 and June 20... Most pairs apparently raise one brood. Nests are built solely by the female." E. Length of incubation period Davis (1960), reports about 12 days, Hastings Reservation. Baumann (1959), reports 13 or 14 days. F. Length of nestling period Baumann (1959), "young birds were found to leave the nest when from nine to eleven days of age" (range for five broods) . G. Growth rates Baumann (1959), detailed description of development of plumage from day 1 to day 8, including photographs. Austin (1968), "In common with most passerines, the growth rate of the young towhees is very rapid. The weight of these nestlings increased about fourfold during the six days of observation." H. Post-breeding behavior Baumann (1959), "About one month after leaving the nest the young were independent. The immature birds were un- disturbed as they frequented common feeding grounds in the territories of the breeding pairs. . .About two weeks after appearing at the common feeding grounds, the young birds commenced to disappear, and most left within a month. Within two weeks after the appearance of the first set of immatures, another group appeared in the common feeding ground." Austin (1968), "after the young leave the nest the family stays together near the nesting site all summer. Young of the year in full juvenile plumage are seen reg- ularly in July. As the singing of the males diminishes after the nesting season, the birds become relatively in- conspicuous as they forage quietly in the dense cover of their preferred habitat.' % Pipilo erythrophthalmus (con't.) 711 POPULATION PARAMETERS A. Clutch size Dawson (1923), "3 or 4; white or palest bluish, grayish, or pinkish, finely and heavily and often uniformly sprinkled or spotted with reddish brown." B. Fledging success C. Mortality rates per age class D. Longevity Linsdale (1949), banding at Hastings Reservation revealed 6 individuals survived to age five; 4 to age six; 1 to age seven. Davis (1957b), discussion of uses of color of primary coverts, shape of rectrices, width of white spot on 4th rectrix, amount of wear on wings and tail, and color of iris to age individuals. Summer (1931), reports, from banding records, two individuals at least seven years of age. Kennard (1975) lists this species with a record age of 12 years, 3 months when banded. E. Seasonal abundance F. Habitat density figures Gaines (1974), reports 92 and 94 territorial males/km^ in 1972 and 1973 in clumped cottonwood and willow woodland in Butte Co.; 38 territorial males/km^ in brushy field and cottonwood and willow edge, Glenn and Butte counties; 60/km^ in cottonwood and willow woodland, Glenn; 62 and 58/km^ in riparian oak woodland, Sacramento Co., 1971 and 1972. VIII INTERSPECIFIC INTERACTIONS A. Predation Davis (1960), discusses the probability of the Scrub Jay, the king snake, and the California ground squirrel as serious predators. Baumann (1959), "The presence of a jay within their territory would definitely affect the behavior of the townees." Bond (1939), noted one carcass under a Prairie Falcon nest. B. Competition • 10 Pipilo erythrophthalmus (con't.) C. Parasitism Rowley (1930), reports a nest containing 3 eggs of the towhee and one of the Dwarf Cowbird (Molothrus ater obscurus) , the nest still occupied by the towhees. Hanna (192871 re- ports one Molothrus ater obscurus egg in a nest of P. m. megalonyx. Rockwell (1908), reported parasitized by M. a. obscurus in Mesa Co., Colorado. IX STATUS A. Past population trends Grinnell and Miller (1944), P. e. curtatus : "common on breeding grounds in summer; winter visitants to other areas occur only in small numbers." P. e. montanus: "Resident, so far as known; probably descends from higher mountains in winter. Common." P. e. megalonyx: "Permanent resident. Common; in some areas rated as abundant' . " B. Present population status Small (1974), "primarily resident" (California). C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status C 11 Pipilo erythrophthalmus (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Austin, 0. L. , Jr. 1968. Life histories of North American cardinals, grosbeaks, buntings, townees, finches, sparrows, and allies. Part 1. U.S. Natl. Mus. Bull. No. 237. Baumann, S. A. 1959. The breeding cycle of the Rufous- sided Towhee, Pipilo erythrophthalmus (Linnaeus), in central California. Wasmann J. Biol. 17:161-220. Bond, R. M. 1939. Observations on raptorial birds in the Lava Beds-Tule Lake region of northern California. Condor 41:54-61. Borror, D. J. 1975. Songs of the Rufous-sided Towhee. Condor 77:183-195. Cardiff, E. A. 1956. Additional records for the Imperial Valley and Sal ton Sea area of California. Condor 58:447- 448. Davis, J. 1957a. Comparative foraging behavior of the Spotted and Brown Towhees. Auk 74:129-166. Davis, J. 1957b. Determination of age in the Spotted Towhee. Condor 59:195-202. Davis, J. 1958. Singing behavior and the gonad cycle of the Rufous- sided Towhee. Condor 60:308-336. Davis, J. 1960. Nesting behavior of the Rufous- sided Towhee in coastal California. Condor 62:434-456. Davis, J. 1961. Some seasonal changes in morphology of the Rufous- sided Towhee. Condor 63:313-321. Dawson, W. L. 1923. The birds of California. South Moulton Co. , San Francisco. Gaines, D. 1974. A new look at the nesting riparian avifauna of the Sacramento Valley, California. Western Birds 5: 61-80. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 12 Pipilo erythrophthalmus (con't.) Groskin, H. 1950. Additional observations and comments on "anting" by birds. Auk 67:201-209. Hanna, W. C. 1928. Notes on the Dwarf Cowbird in southern California. Condor 30:161-162. Kennard, J. H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. Linsdale, J. M. 1949. Survival in birds banded at the Hastings Reservation. Condor 51:88-96. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool., Vol. 50, no. 6. Peters, J. L. 1970. Checklist of birds of the world. Vol. 10. (R. A. Paynter, Jr., ed.) Mus. Comp. Zool., Cambridge, Massachusetts. Peterson, R. T. 1961. Field guide to western birds. Houghton Mifflin Co. , Boston. Ridgway, R. 1901. The birds of North and Middle- America. Part 1. U.S. Natl. Mus. Bull. No. 50. Rockwell, R. B. 1908. An annotated list of the birds of Mesa Co., Colorado. Condor 10:169. Rowley, J. S. 1930. Observations on the Dwarf Cowbird. Condor 32:130-131. Small, A. 1974. The birds of California. Macmillan Co., New York. Sumner, E. L. 1931. Some banded birds recaptured after five to seven and one-half years. Condor 33:128. Swarth, H. S. 1913. A revision of the California forms of Pipilo maculatus Swainson, with description of a new sub- species. Condor 15:167-175. Willett, G. 1912. Birds of the Pacific slope of southern California. Pacific Coast Avifauna No. 7. Woodbury, A. M. 1933. The scratching of the Spurred Towhee. Condor 35:70. € SAGE THRASHER Oreoscoptes montanus I TAXONOMY A. Type description Oreoscoptes montanus - AOU (1957) J. K. Townsend, Journ. Acad. Nat. Sci. Philadelphia, 7, pt. 2, Nov. 21, 1837, p. 192. (Plains of the Rocky Mountains = Sandy Creek, lat. 42 N. , long. 109. 30' W. , Wyoming.). B. Current systematic treatments Hellmayr (1934) describes the Sage Thrasher as a monotypic species, with a general range described as "Arid sagebrush plains and foothills of western United States." AOU (1957) considers the Sage Thrasher a monotypic member of the order Passeriformes, family Mimidae. Mayr and Short (1970), "given the variation with Toxo stoma, Oreoscoptes is doubtfully separable from it." C. Synonomies of scientific nomenclature Hellmayr (1934), Orpheus montanos ; Oroscoptes montanus. Grinnell and Miller (1944), Mimus montanus. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Mountain Mockingbird. Dawson (1923) adds "Sage Mocker." II DESCRIPTION A. External morphology of adults Ridgway (1907) gives detailed description of plumages for all age classes; "above light grayish brown, the feathers... producing very indistinct streaks.'" Peterson (1961), "gray- backed with a Robin-like bill, heavily streaked breast, white spots at tip of tail, pale yellow eye." Phillips et al. (1964) "the chest spots are dark, and the tail corners are white. The bill is short... the iris yellow." Ligon (1961), 8-9 inches long. Dawson (1923) described this thrasher as towhee size; ashy-brown. . .abundant spotting. Oreoscoptes montanus (con't.) B. External morphology of subadult age classes f£ Ridgway (1907) noted that young were "...light grayish brown ...back, scapulars, and rump rather broadly streaked... streaks on under parts less sharply defined than in adults." Dawson (1923) notes that young birds are browner and more streaked than adults. C. Distinguishing characteristics Interspecific - Peterson (1961), "small size (8-9 inches), Shorter tail, shorter bill, striped breast distinguish it from other. . thrashers." Phillips et al. (1964), "this is our only thrasher with a fairly definite facial pattern." Grinnell (1904) thought this thrasher could be confused with Cactus Wrens. Intraspecific - Ridgway (1907) describes adults as nearly identical in plumage, with some size differences; male: wing 98.7 mm, length 197 mm, tail 88.5 mm. Ligon (1961), "color pattern of sexes alike." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species C Distribution of 0. montanus (AOU 1957) given as, "Breeds from central southern British Columbia, central Idaho, central southern Montana, and northern and southeastern Wyoming, with an apparently isolated colony in southwestern Saskatchewan, south through eastern Washington, eastern Oregon, and eastern California (Macdoel, Eagle Lake, White Mtns. , Inyo Mtns.) to central southern California (Buena Vista Lake, Lockwood Valley, Victorville) , southern Nevada, Utah, central northern New Mexico, northwestern Texas, and western Oklahoma." Ridgway (1907) gives general range as the arid plains, mesas, and foothills of western United States. Peterson (1961) gives range as, "from British Columbia, Idaho, Montana, Saskatchewan, south to southern California, Nevada, northern Arizona, New Mexico, Texas panhandle, Oklahoma." B. California distribution of the species Grinnell and Miller (1944), "As breeding, Great Basin plateau region, east of the Cascade-Sierran axis from the Oregon line south to northern end of Owens Valley and White Mtns. , thence irregularly southward at higher levels in mountains around northern, western, and southern margins of Mohave Desert." Small (1974), "breeds in Great Basin Desert south to northern edges of Mojave Desert and Walker Basin, Kern Co. ; also... San Joaquin Valley." Dawson (1923)," breeds locally C Oreoscoptes montanus (con't.) in the high upper Sonoran, Sagebrush areas, east of the Sierra Nevada, south to the Panamint Mtns." Wheelock (1904) gives California breeding ranges as, "in upper Sonoran zone southeast of the Sierra Nevada." C. California desert distribution Grinnell and Miller (1944) note the winter distribution of this thrasher in the Mohave and Colorado deserts; desert records include: Inyo and Panamint Mtns. ; near Walker Pass, Kern Co.; near Bakersfield and Buena Vista Lake, Kern Co.; Lockwood Valley, Ventura Co. ; vicinity of Victorville; Death Valley, Inyo Co.; Hesperia and Twentynine Palms, San Bernardino Co. Dawson (1923) notes sporadic nesting near Bakersfield and Walker Pass. Johnson et al. (1948) found wintering thrashers near Cima in the Providence Mtns. at 4,500 ft. Called an April to May transient near Blythe, Calif. (Grinnell 1914). Breeds in some high valleys in northeastern Ventura Co. and along desert slope of San Gabriel and San Bernardino Mountains, south at least to Victorville; noted near Perris, Riverside Co. (Willett 1933). Apparently reaches its highest numbers on the desert in winter, with Willett (1951) calling it the "most common thrasher" in winter. Miller and Stebbins (1964) state that although the species does not breed at Joshua Tree National Monument, there are regular breeders on the Mojave Desert near Victorville. Wauer (1964) found Sage Thrashers breeding on open sage flats and valleys of the Panamint Mtns., Death Valley. Rowley (1928) and Hanna (1930) found Sage Thrashers nesting near Victorville, the most southerly desert locations noted. D. Seasonal variations in distribution Grinnell and Miller (1944), "present in two seasonal roles: summer resident in Artemisia tridentata belt of eastern California; winter visitant (late September-April) to deserts and coastal slopes of southern California and to San Joaquin Valley." Small (1974), "summer visitor (on breeding grounds) and transient and winter visitor (September- April) elsewhere; winters south to... Mojave and Colorado deserts." Winters on the southeastern deserts and... in the San Diegan district (Dawson 1923). In winter in southern California, this bird occurs on Pacific slope, north to Ventura Co. and south to Baja California (Willett 1933). "Common winter visitant to the deserts of southeastern Calif ornia. .. summer visitant to sagebrush of northeastern California" (Grinnell 1915). The Sage Thrasher is called a rare straggler into Los Angeles Co. from the desert by Grinnell (1898); pair seen in March. Wintering birds usually arrive after mid- September at Joshua Tree National Monument, with the earliest record being September 13 (Miller and Stebbins 1964). Bent (1948) states Oreoscoptes mem t anus (con't.) that this thrasher is migratory, spending the winter near ca or beyond the southern border of the United States. He notes the California winter range to include San Fernando, Twenty- nine Palms, and Death Valley. The species usually departs its more northern breeding range in September. Gullion et al. (1959) calls this species a spring and fall migrant on southern Nevada deserts; most birds migrate north by mid- April. Torrey (1909) found a single Sage Thrasher wintering near San Diego (city park) in 1908. Van Rossem (1911) listed this species as a regular winter visitor in the Salton Sea region (noted in March). Howell and Van Rossem (1915) discovered a single Sage Thrasher wintering (January) in the Lower Colorado River Valley in 1913. Gilman (1907) describes the migrations and habits of Sage Thrashers on southern California deserts. IV HABITAT A. Biotopic affinities Peterson (1961) describes habitat as, "sagebrush brushy slopes, mesas; in winter, also desert." 'A common short- tailed desert bird. . .nests in arid country (Robbins et al. 1966)." Grinnell and Miller (1944), "mesas and slopes of moderate inclination, well covered with Artemisia tridentata. Much less frequently other shrubs of similar growth pattern, such as rabbitbrush, provide the necessary cover for nesting and escape." Small (1974), "for breeding, flat areas vege- tated primarily with Great Basin Sagebrush." Ligon (1961), "the Latin designation, montanus , implying that it is a moun- tain bird, is misleading" since it shuns the higher, heavily forested areas." In southern California, species is most plentiful on brushy foothills and mesas, but occasionally straggling to lowlands (Willett 1933). Grinnell (1904) found Sage Thrashers in creosote brush near Palm Springs, California, during winter. B. Altitudinal range Grinnell and Miller (1944), "probable breeding, 300 ft... up to 10,500 ft. on White Mountain." Breeds in New Mexico between 5,000 and 6,000 ft. (Bailey 1928). Rossem (1936) found this thrasher on the desert and up to 5,000 ft. in the Yucca belt. Found nesting (May) at 5.000 ft. in Lockwood Valley, Ventura Co., by Willett (1933). Bent (1948) notes this thrasher up to 4,000 or even 6,000 ft. in juniper wood- lands. Wauer (1964) noted nesting Sage Thrashers between 4,000 and 5,000 ft. in the Panamint Mountains, Death Valley. Oreoscoptes montanus (con't.) D. Territory requirements Perch sites - Bent (1948) lists posts and the tops of bushes as favorite perch sites. Pearson (1936) describes the favor- ite perches of Sage Thrashers as sagebrush and thorny cactus. Courtship and mating sites - Bailey and Niedrach (1965), "...during spring and early summer... the males perch on the tips of vegetation. .. singing for the benefit of their mates..." Nest sites - Nest a twiggy cup in bush (Peterson 1961). Bailey (1928) - nest, on ground or in low bushes, especially sagebrush. Dawson (1923), "nest placed... in sage-bush or greasewood." Nest. . .placed in sagebrush from 10 inches to 3 ft. from the ground (Wheelock 1904). Bent (1948) gives usual sites as from a few inches to 3ft. above ground, usually in sage, greasewood, or rabbi tbrush. Hanna (1930) found nests in cotton thorn (Tetradymia spinosa) near Victor- ville, Calif., 18 inches from the ground. Gilman (1907) describes several sagebrush nests within 3 ft. of the ground near 6,000 ft. in Colorado. E. Special habitat requirements Burleigh (1972) states that the Sage Thrasher has very exacting habitat requirements, being restricted to sage- brush. F. Seasonal changes in habitat requirements Grinnell and Miller (1944), "in winter, brushland associa- tions of much wider variety are frequented (than summer range)." Small (1974) noted that Sage Thrashers move into more open country with sparse arid vegetation during winter. Carter (1937) found this thrasher in the mesquite between an oasis and the open desert near Twentynine Palms, San Bernardino Co. , during winter. V Food A. Food preferences Bailey (1928) noted food items such as berries, seeds, fruit, beetles, locusts, ants, small wasps, other insects; as high as 62% grasshoppers. Wheelock (1904) mentions the taking of worms and insects. Martin et al. (1951) lists: beetles, grasshoppers and crickets, ants and other Hymenoptera, cater- pillars and moths, spiders, bugs, and flies; states that little plant food is taken, although grape, serviceberry, and blackberry have been found in diet. Bent (1948) gives detailed summary of food items; grasshoppers, chinch bugs, leaf hoppers, ants, and a few berry seeds. Knowlton and Harmston (1942) gave a detailed summary of Sage Thrasher prey in Utah; grasshoppers were the major prey taken. Oreoscoptes montanus (con't.) B. Foraging areas Grinnell and Miller (1944), "the ground between arid beneath bushes, and to some degree the bushes themselves, are searched over in foraging." Wheelock (1904) found most Sage Thrashers feeding below bushes in California. During winter at Joshua Tree National Monument, these birds forage in open desert terrain, although they utilize as retreats the low shrubs and bushes present there (Miller and Stebbins 1964). Pearson (1936) noted that Sage Thrashers are seldom seen far from the ground. C. Foraging strategies "He would run to a bush. .if bushes were far apart he would sometimes fly from one cover to another, halt, and then forward again" (Gilman 1907). Bent (1948) states that al- though the majority of feeding takes place on the ground, this thrasher will feed on grapes and berries in low shrubs. Pearson (1936), "it is found on the ground, running about among the clumps of bushes." D. Feeding Phenology Feed primarily on berries during the non-breeding season (Dawson 1923). Little plant material is taken by this species; serviceberry and grape are favored in the fall (Martin et al. 1951). Kennedy (1911), "with young independ- ence, habits change greatly. After July, Sage Thrashers feed heavily on grapes" (Washington). E. Energy requirements VI REPRODUCTION A. Age at first breeding B. Territorial behavior Bent (1948) states that the Sage Thrasher acts somewhat like the Mockingbird. It frequently raises its tail rapidly, moving its head from side to side at an intruder. C. Courtship and mating behavior "Song, given from conspicuous perch or in flight, resembles Brown's (Thrasher), but is more melodious and lacks the pauses between phrases (Robbins et al. 1966)." Ligon (1961), its song... is somewhat like that of the Mockingbird." During pairing, the males often fluttered their wings and gave a warbling song as they flew; they flew in a zigzag fashion over the sage (Bent 1948). Qreoscoptes montanus (con't.) t D. Nesting phenology Dawson (1923) gives breeding season as May 1 to June 15 with 1 or 2 broods raised; the nesting season is very ir- regular, however. Wheelock (1904) gives California season as March to July. Bent (1948) gives California egg dates as 19 April to 18 July; most nesting begins in mid-April. E. Length of incubation period Incubation period of 14 days given by Wheelock (1904). F. Length of nestling period Killpack (1970) found an 11 day nestling period in Colorado Sage Thrashers. G. Growth rates General account of development given by Wheelock (1904); down more perceptible by second day; eyes open by fifth day. In Colorado, nestlings gained an average of 3.4 (1.5- 4.7) g. per day; their average weight was 87% of adult females at fledging (Killpack 1970). j H. Post-breeding behavior Form large flocks after breeding (Bailey 1928). "At the close of the (nestling) season. ..the birds. . .resort in numbers to the hillside springs and brushy draws (Dawson 1923)." In the late summer, family groups band together (Bailey and Niedrach 1965) . VII POPULATION PARAMETERS A. Clutch size Eggs (4-5; 7) blue, spotted (Peterson 1961). Bailey (1928) gives clutch as 4 eggs. Reed (1904) gives clutch of 3-4. Ligon (1961), "eggs 4, greenish blue, spotted." Eggs 4 or 5 (Dawson 1923). Bent (1948) reports the normal clutch as 4 or 5 eggs, with 7 being the record. B. Fledging success In Colorado, Killpack (1970) stated that nest success was variable. Of 19 eggs laid, 11 young hatched and all 11 fledged. C. Mortality rates per age class Wheelock (1904) felt that lizards and snakes took a large number of eggs and nestlings in California. 8 Oreoscoptes montanus (con't.) D. Longevity E. Seasonal abundance Carter (1937) states that wintering Sage Thrashers near Twentynine Palms, California, vary widely in numbers from year to year, from "quite numerous" to rare. After breed- ing, family groups form and the birds become fairly numer- ous around waterholes (Bailey and Niedrach 1965). F. Habitat density figures Hoppes (1978) found 2 territorial males on a 12.26 ha "Sagebrush flat" study area in Wyoming. On another sage- brush study area, also in Wyoming, Todd (1974) reported 1 territorial male on an 8.1 ha plot. Jewett (1953) reported a density of 5 pairs per square mile in Washington. VII INTERSPECIFIC INTERACTIONS A. Predation Killpack (1970) noted the taking of eggs by a coyote in Colorado. B. Competition C. Parasitism Friedmann (1963) gives a single record of the Sage Thrasher being parasitised by a cowbird (Utah) . IX STATUS A. Past population trends Called "common" by Grinnell (1915). Bent (1948) notes a slight northward range expansion during the early 1940' s. Called a common wintering bird along the lower Colorado River (Price 1899). Mailliard and Grinnell (1905) described the thrasher as "unexpectedly rare" on the Mojave Desert in winter. Hollister (1908) called the species "common and in full song in April (1905) near Needles, California. B. Present population status Grinnell and Miller (1944), "Common, even abundant locally, on breeding grounds; common in eastern part of winter range." Miller and Stebbins (1964) listed the birds as "fairly com- mon" during winter at Joshua Tree National Monument. Called a "common breeder" in eastern California (McCaskie and De Benedictis.1967) . Oreoscoptes montanus (con't.) C. Population limiting factors Bent (1948), "...it is limited almost entirely to the semiarid regions where immense areas are clothed with. .. sage." Pear- son (1936) states that Sage Thrashers appear to be confined very largely to the open areas of the far West. D. Environmental quality: adverse impacts Jewett (1953) stated that agricultural activities (irriga- tion and cultivation) usually drives Sage Thrashers out of an area. However, tracts of sagebrush left adjacent to the agricultural fields will be utilized for nesting. E. Potential for endangered status 10 Oreoscoptes montanus ( con ' t . ) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bailey, F. M. 1928. Birds of New Mexico. New Mexico Dept. Game and Fish. 807 pp. Bailey, A. M. and R. J. Niedrach. 1965. Birds of Colorado. Vol. 2. Denver Mus. Nat. Hist., Denver, Colorado. Bent, A. C. 1948. Life histories of North American nuthatches, wrens, thrashers, and their allies. U.S. Nat. Mus. Bull. 195:1-475. Burleigh, T. D. 1972. Birds of Idaho. Caxton Printers, Ltd., Caldwell, Idaho. 467 pp. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39: 210-219. Dawson, W. L. 1923. The birds of California. Vol. 2. South Moulton Co. , San Francisco. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233. 276 pp. Gilman, M. F. 1907. Migration and nesting of the Sage Thrasher. Condor 9:42-44. Grinnell, J. 1898. Birds of the Pacific slope of Los Angeles County. Pasadena Academy Sci. No. 11:1-52. Grinnell, J. 1904. Midwinter birds at Palm Springs, Calif- ornia. Condor 6:40-45. Grinnell, J. 1914. An account of the mammals and birds of the lower Colorado Valley. Univ. California Publ. Zool. 12:51-294. Grinnell, J. 1915. A distributional list of the birds of California. Pacific Coast Avifauna No. 11. 217 pp. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp. Gullion, G. W., W. M. Pulich and F. G. Evenden. 1959. Notes on the occurrence of birds in southern Nevada. Condor 61: 278-297. : 11 Oreoscoptes montanus (con't.) Hanna, W. C. 1930. Southerly breeding record of Sage Thrasher in California. Condor 32:263. Hellmayr, C. E. 1934. Catalogue of birds of the Americas. Part 7. Field Mus. Nat. Hist. Zool. Ser. Publ. 330, Vol. 13. Hollister, N. 1908. Birds of the region about Needles, Cal- ifornia. Auk 25:455-462. Hoppes, W. 1978. Forty-first breeding bird census. Am. Birds 32:97. Howell, A. B. and A. Van Rossem. 1915. Additional observations on the birds of the Lower Colorado Valley in California. Condor 17:232-234. Jewett, S. G., W. P. Taylor, W. T. Shaw and J. W. Aldrich. 1953. Birds of Washington State. Univ. Washington Press, Seattle. 767 pp. Johnson, D. H. , M. D. Bryant and A. H. Miller. 1948. Verte- brate animals of the Providence Mountains area of Calif- ornia. Univ. California Publ. Zool. 48:221-376. Ligon, J. S. 1961. New Mexico birds. Univ. New Mexico Press, Albuquerque. 360 pp. Kennedy, C. H. 1911. Notes on the fruit-eating habits of the Sage Thrasher in the Yakima Valley. Auk 28:225-228. Killpack, M. L. 1970. Notes on Sage Thrasher nestlings in Colorado. Condor 72:486-488. Knowlton, G. F. and F. C. Harmston. 1942. Insect food of the Sage Thrasher. Condor 44:76-77. Mailliard, J. and J. Grinnell. 1905. Midwinter birds on the Mohave Desert. Condor 7:71-77, 101-102. Martin, A. C. , H. S. Zim and A. L. Nelson. 1951. American wildlife and plants. McGraw-Hill Book Co., New York. 500 pp. Mayr, E. and L. L. Short. 1970. Species taxa of North American birds. Publ. Nuttall Ornithol. Club 9:1-127. McCaskie, G. and P. De Benedictis. 1967. The distribution of certain Mimidae in California. Condor 69:310-311. 12 Oreoscoptes montanus (con't.) Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Pearson, T. G. 1936. Birds of America. Garden City Publ. Co., Inc., Garden City. N.Y. Peterson, R. T. 1961. A field guide to western birds. 2nd Edition. Houghton Mifflin Co., Boston. 366 pp. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. 212 pp. Price, W. W. 1899. Some winter birds of the Lower Colorado Valley. Condor 1:89-93. Reed, C. A. 1904. North American birds eggs. Doubleday, Page & Co., New York. 356 pp. Ridgway, R. 1907. The birds of North and Middle America. Part 4. Bull. U.S. Nat. Mus. No. 50. Robbins, C. S., B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Rowley, J. S. 1928. Sage Thrasher nesting near Victorville, California. Condor 30:325. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Swarth, H. S. 1900. Sage Thrasher in Los Angeles Co., Cal. Condor 2:89. Todd, F. W. 1974. Thirty-eighth breeding bird census. Am. Birds 28:1044. Torrey, B. 1909. The Sage Thrasher at San Diego. Condor 11:174. Van Rossem, A. 1911. Winter birds of the Salton Sea region. Condor 13:129-137. Van Rossem, A. 1936. Birds of the Charleston Mountains, Nevada. Pacific Coast Avifauna No. 24. 65 pp. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Wheelock, I. G. 1904. Birds of California. A. C. McClurg and Co., Chicago. 578 pp. 13 Oreoscoptes montanus (con't.) Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles Co. Mus. Zool. Ser. 6:1-39. m m i SOLITARY VIREO Vireo solitarius cassinii I TAXONOMY A. Type description Vireo solitarius cassinii - AOU (1957) Vireo cassinii Xantus, Proc. Acad. Nat. Sci. Philadelphia, 10, sig. 8, Apr*-May (after May 25) 1858, p. 117. (Fort Tejon, California.) B. Current systematic treatments AOU (1957) considers Vireo solitarius a member of the avian Order Passeriformes, Family Vireonidae, Subfamily Vireoninae. Hellmayr (1935) lists 7 races of Vireo solitarius, including cassinii. Hamilton (1962) presents a detailed study of the relationships within the genus Vireo. V. solitarius is most closely related to V. f lavifrons, V. atricapillus, and V. huttoni. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Vireo cassinii, Vireosylvia solitaria; Lanivireo solitarius; L. cassinii. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Cassin Vireo; Blue-headed Fly- catcher; Blue-headed Vireo; Blue-headed Greenlet; Cassin Greenlet. II DESCRIPTION A. External morphology of adults Miller and Stebbins (1964): "A large (14-16 gram) vireo with heavy bill. Gray head marked with conspicuous white eye ring connected with white running to base of bill; two prominent white wing bars on secondary coverts; back and flanks greenish." Ridgway (1904) adds that the "mandible grayish (pale bluish gray in life) with blackish tip; iris brown; legs and feet dusky." Hamilton (1958) gave a detailed analysis of geographic variation in the genus Vireo. B. External morphology of subadult age classes Ridgway (1904) described young as: "(in first autumn and winter) --Pileum, hindneck and sides of head and neck varying from olivaceous hair brown to grayish olive, not very differ- ent...from color of back; (first plumage) --Wings and tails as in adults; rest of upper parts brownish gray." ^ Vireo solitarius (con't.) C. Distinguishing characteristics Interspecific - Peterson (1961), "Similar species: (1) Hutton s Vireo has dull throat; eye-ring broken at top. (2) Bell's Vireo has inconspicuous wing-bars and eye- ring." Intraspecific - Ridgway (1904), "Adult female—Similar to adult male but duller in color; length 121.7 mm; wing 72.1; tail 52.0; Adult male, length 123.2 mm; wing 72.3; tail 52.3." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) gives the overall distribution of the Solitary Vireo as "Breeds from central "Bitish Columbia, southwestern Mackenzie, central Saskatchewan, central Manitoba, northern Ontario, southern Quebec, Newfoundland, and Nova Scotia south to southern Baja California, Guatemala, and El Salvador. Winters from Arizona and South Carolina south to the Cape district of Baja California, southwestern Mexico, northern Nicaragua, and Cuba." The range of Vireo solitarius cassinii is given by the AOU (1957) as "Breeds from southern British Columbia, northern S^L Idaho, and northwestern Montana south through central northern Washington, northeastern Oregon, central Idaho to the moun- tains and foothills of California (Humboldt County, Warner Mountains, Campo, Kings Canyon) and southern Nevada (Poyosi Mountain) . " Hellmayr (1935) gives range of cassinii as "Transition zone from British Columbia, southwestern Alberta, Idaho, and western Montana south through California and western Nevada to the Sierra San Pedro Martir, Lower California; in winter south through Arizona to Jalisco, Michoacan, Guanajuato, Oaxaca, and Chiapas." B. California distribution of the species Small (1974), "range in California--for breeding, foothills and mountains of most of California east of the deserts and excluding the humid coniferous forest of the northwest coast; in migration, throughout state." McCaskie (1968) called solitarius "a regular migrant and summer visitor between late March and mid-October with stragglers regularly occurring in November." He further notes that the appearance of birds in December may mean that the species now winters in Calif- ornia. % Vireo solitarius (con't.) C. California desert distribution Miller and Stebbins (1964) called this vireo a "sparse but regular spring migrant" in Joshua Tree National Monument; recorded from Lower Covington Flat, Smithwater Canyon, Twentynine Palms, Eagle Mountain, and Cottonwood Spring, from March to May. Only one fall record, on 17 September. Willett (1951) calls this species a migrant across the deserts of southern California. Johnson et al. (1948) called cassinii uncommon migrants, with no evidence of breeding^ in the Providence Mountains in May. Grinnell (1914) called cassinii a transient during April in the lower Colorado River valley. Grinnell and Swarth (1913) noted that this vireo was "Found in fair abundance in. . . the Transition Zone" of the San Jacinto area of southern California. Van Rossem (1936) called this vireo "a common late-August migrant" in the Charleston Mountains, Nevada (near Death Valley, California) ; he could find no evidence of breeding, however. Johnson (1974) found that V. _s. cassinii has been replaced by V. s. plumbeus in some areas of southern Nevada (Grapevine and Potosi Mountains). De Benedictis and McCaskie (1967) collected singing male V. _s. plumbeus in the White Mountains of California during July; they feel that this race may breed in these mountains. Cardiff (1963) collected a male plumbeus near Needles. San Bernardino County, on 26 November 1960. Miller (1945) found cassinii breeding on Potosi Mountain (South Nevada), but could not find breeders on Clark Mountain (San Bernardino County) or in the Charleston Mountains. At Twentynine Palms, Carter (1937) called cassinii a "casual spring migrant"; was noted between late-March and mid-May. D. Seasonal variations in distribution AOU (1957) states that V. s. cassinii "Winters from south- eastern Arizona and Nuevo Leon south to Michoacan and Guerrero. Migrates through the Great Basin region through Colorado, New Mexico, and western Texas." Grinnell and Miller (1944) found that this species is pre- sent in two seasonal roles in California: "summer resident, on nesting grounds, from mid-April through August; migrant ...from the first of April through May, and from late August through the first half of October, rarely later." In Joshua Tree, the protracted period of passage through the desert suggests the presence of populations moving both to southern and northern parts of the breeding range of the race (cassinii) (Miller and Stebbins 1964; . Small (1974) in California, "transient and summer visitor, late March to October." Vireo solitarius (con't.) IV HABITAT A. Biotopic affinities Grinnell and Miller (1944) describe this species California habitat as "oak and conifer forests that offer open branch- work at low and middle levels. . .Comparatively dry, warm forests are favored. .. Principal trees frequented in summer are yellow pine, Jeffery pine, incense cedar, black oak, and golden oak; mature willows, cottonwoods and alders also may be occupied." Small (1974) gives California habitat as "for breeding, oak woodlands and mixtures of oaks and conifers; otherwise, lowlands in general where there are thickets, riparian woodlands..." In the Charleston Moun- tains of Nevada, Van Rossem (1936) found late-August migrants through the Upper Sonoran and Transition Zones. Johnson et al. (1948) found cassinii "in a juniper among rocks on a steep hillside at 6,300 feet on the southeast side of Clark Mountain." During a May study in the Providence Mountains. Hamilton (1962) noted that "The Solitary Vireo appears to be the only vireo sufficiently wide in habitat tolerance to utilize coniferous vegetation. .. the breeding territories are usually in broadleaved or mixed broadleaf -conifer habitats." 41 B. Altitudinal range %t>-" In California, nesting from 300 feet (Contra Costa Co.) to 7,500 feet (Tulare County) (Grinnell and Miller 1944). Fall migrants were observed from 6,200 to 9,000 feet in Nevada by Van Rossem (1936). In Kings Canyon National Park, Dixon (1943) found cassinii up to 6,000 feet. C. Home range size In Arizona, Launders layer and Balda (1976) gave the mean size of a breeding territory as 1.7 ha. D. Territory requirements Perch sites - Courtship and mating sites - Nest sites - "Nest emplacements usually are in the lower branches of... trees, not uncommonly in exposed, though shaded, situations" Grinnell and Miller (1944). Bent (1950), "it ...builds its dainty nest low in bushes or trees." Ligon (1961), "nest: From 5 to 20 feet above ground." In the San Bernardino Mountains, Grinnell (1908) found nests in "golden oaks at lower levels and cottonwoods at higher altitudes... but nests were also found in the incense cedar, silver fir, Jeffrey pine, black oak, and alder." Vireo solitarius (con't.) E. Special habitat requirements During nesting, Grinnell and Storer (1924) found that the distribution of cassinii "closely parallels the range of golden oak and incense cedar, though the bird does not restrict itself exclusively to these two trees." F. Seasonal changes in habitat requirements Grinnell and Storer (1924) reported that cassinii is found in blue oaks and chaparral on dry hillsides during spring migration, while in the fall, they wander up in the Hudsonian Zone before leaving for wintering grounds. Phillips and Amadon (1952) found cassinii wintering in mesquite thickets in Sonora, Mexico. V FOOD A. Food preferences Martin et al. (1951) found that "the food of vireos is primarily insects. .. caterpillars, moths, bugs, beetles, wasps, ants, bees, and flies. Spiders are also taken." Bent (1950) stated that animal matter accounted for 98.0% of the diet--Hemiptera (51.0%), Lepidoptera (23.0%). B. Foraging areas Bent (1950) reported that this vireo "lives mainly in trees of the forest and obtains most of its food among the twigs and foliage." Hamilton (1962) described V. solitarius as an "arboreal forager", utilizing the crown- to- shrub area of a woodland. C. Foraging strategies The Solitary Vireo was described as a "foliage gleaner" by Bent (1950). Hamilton (1962) noted that Solitary Vireos normally glean broadleaved foliage for insects. D. Feeding phenology Bent (1950) reported that although vegetable matter makes up less than 5% of the yearly diet of this species, up to one quarter of the diet may be plant material during winter (January) . E. Energy requirements » ' ^ Vireo solitarius (con't.) VI REPRODUCTION A. Age at first breeding B. Territorial behavior The male apparently wanders about the territory while sing- ing, with no fixed singing post (Bent 1950). C. Courtship and mating behavior Bent (1950) recounted that the male "bobs and bows to the female... and sings repeatedly." In New Mexico, Tatschl (1967) noted singing males between 28 April and 26 September. D. Nesting phenology Bent (1950) gives California egg dates as "100 records, April 26 to July 9; 52 records, May 20 to June 6, indicating the height of the season." E. Length of incubation period Bent (1950) concluded that the incubation period was at least 11 days; both sexes incubate. C> F. Length of nestling period G. Growth rates H. Post-breeding behavior VII POPULATION PARAMETERS A. Clutch size Bent (1950) reported that cassinii lays 3-5 eggs. Ligon (1961), "Eggs: 4; white, lightly spotted around larger end with brown and black," B. Fledging success C. Mortality rates per age class In southern California, Edwards (1919) noted the frequent destruction of nests and eggs by rain and windstorms. D. Longevity < Vireo solitarius (con't.) E. Seasonal abundance In Oregon, Anderson (1970) located 8 Solitary Vireos per 100 acres between June and February, but only 4 per 100 acres between March and May. F. Habitat density figures In white oak stands of Oregon, Anderson (1970) found 4 to 8 Solitary Vireos per 100 acres during all season of the year. In an oak-juniper-pine woodland of southern Arizona, Balda (1970) reported 5 breeding pair per 100 acres. Bock and Lynch (1970) found 0.5 pair of Solitary Vireos breeding per 100 acres in an unburned conifer forest of the Sierra Nevada; this species was not present in a similar, but burned, plot. In a ponderosa pine forest in southeastern Arizona, Balda (1969; recorded a breeding population of 14 pair of Solitary Vireos per 100 acres. Johnston (1949) found a breeding density of 10 to 20 pairs per 100 acres in a Douglas fir dominated area in Idaho. Launderslayer and Balda (1976) found 9.9 pairs per 100 ha in a Arizona pinyon-juniper- ponderosa pine ecotone. jVIII INTERSPECIFIC INTERACTIONS A. Predation B. Competition Hamilton (1962) found that in areas of sympatry, V. solitarius, V. atricapillus, and V. vicinior reduce competition through altitudinal segregation. C. Parasitism Friedmann (1963) and Friedmann et al. (1977) found that 6.7% of cassinii nests were parasitized by Brown-headed Cowbirds. IX STATUS A. Past population trends Grinnell and Miller (1944) called cassinii "common" in Calif- ornia. In Oregon, cassinii was called "second in abundance among Oregon members of the family" by Gabriel son and Jewett (1940). 8 Vireo solitarius (con't.) B. Present population status In Montana, Weydemeyer (1975) reported that solitarius "has been dwindling in numbers for the past 15 or 20 years However, Johnson (1974) noted that in southern Nevada, "Solitary Vireo. .. either colonized for the first time... or definitely increased in number in both the Grapevine Mountains and on Potosi Mountain." Johnson and Garrett (1974) noted that "the breeding range of V. s. plumb eus has undergone a major westward expansion ourTng the last decade"; race is moving into California. C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status <> «~ Vireo solitarius (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American Birds. Fifth Edition. American Ornithologists' Union, Baltimore, MD. 691 pp. Anderson, S. H. 1970. The avifaunal composition of Oregon white oak stands. Condor 72:417-423. Balda, R. P. 1969. Foliage use by birds of the oak-juniper woodland and ponderosa pine forest in southeastern Arizona. Condor 71:399-412. Balda, R. P. 1970. Effects of spring leaf-fall on composition and density of breeding birds in two southern Arizona wood- lands. Condor 72:325-331. Bent, A. C. 1950. Life histories of North American wagtails, shrikes, vireos, and their allies. U. S. Nat. Mus. Bull. 197:1-411. Bock, C. E. and J. F. Lynch. 1970. Breeding bird population of burned and unburned conifer forest in the Sierra Nevada. Condor 72:182-189. Cardiff, E. A. 1963. Solitary vireo of the race Plumbeus in California. Condor 65:534. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39: 210-219. De Benedictis, P. and R. G. McCaskie. 1967. Cassin's King- bird and plumbeous Solitary Vireo in the White Mountains of California. Condor 69:424-425. Dixon, J. S. 1943. Birds of the Kings Canyon National Park area of California. Condor 45:205-219. Edwards, H. A. 1919. Losses suffered by breeding birds in southern California. Condor 21:65-68. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233:1-276. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the parasitic cowbirds. Smithsonian Contrib. Zool. 235. 75 pp. Gabrielson, I. N. and S. G. Jewett. 1940. Birds of Oregon. Oregon St. Univ., Corvallis. 650 pp. m 10 Vireo solitarius (con't) Grinnell, J. 1908. The biota of the San Bernardino Mountains. Univ. California Publ. Zool. 5:1-170. Grinnell, J. 1914. An account of the mammals and birds of the lower Colorado Valley. Univ. California Publ. Zool. 12: 51-294. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp. Grinnell, J. and T. I. Storer. 1924. Animal life in the Yose- mite. Univ. California Press, Berkeley. 752 pp. Grinnell, J. and H. S. Swarth. 1913. An account of the birds and mammals of the San Jacinto area of southern California. Univ. California Publ. Zool. 10:197-406. Hamilton, T. H. 1958. Adaptive variation in the genus Vireo. Wilson Bull. 70:307-346. Hamilton, T. H. 1962. Species relationships and adaptations for sympatry in the avian genus Vireo. Condor 64:40-68. Hellmayr, C. E. 1935. Catalogue of birds of the Americas. ^jfek Vol. 13, Part 8. Field Mus. Nat. Hist. Zool. Ser. 347. 541 pp. Johnston, D. W. 1949. Populations and distribution of summer birds of Latah County, Idaho. Condor 51:140-149. Johnson, D. H. , M. D. Bryant and A. H. Miller. 1948. Verte- brate animals of the Providence Mountains area of Calif- ornia. Univ. California Publ. Zool. 48:221-376. Johnson, N. K. 1974. Montane avifaunas of southern Nevada: Historical change in species composition. Condor 76:334- 337. Johnson, N. K. and K. L. Garrett. 1974. Interior bird species expand breeding ranges into southern California. Western Birds 5:45-56. Laundens layer, W. F., Jr. and R. P. Balda. 1976. Breeding bird use of a pinyon-juniper-ponderosa pine ecotone. Auk 93:571-586. Ligon, S. J. 1961. New Mexico birds. Univ. New Mexico Press, Albuquerque. 360 pp. Martin, A. C. , H. S. Zim-, and A. L. Nelson. 1951. American wildlife and plants. McGraw-Hill Book Co., Inc., N.Y. 500 pp. «- 11 Vireo solitarius ( con ' t . ) McCaskie, R. S. 1968. Noteworthy records of vireos in Calif- ornia. Condor 70:186. Miller, A. H. 1945. Birds of the yellow pine association of Potosi Mountain, southern Nevada. Condor 47:130-131. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Peterson, R. T. 1961. A field guide to western birds. 2nd Edition. Houghton Mifflin Co., Boston. 366 pp. Phillips, A. R. and D. Amadon. 1952. Some birds of north- western Sonora, Mexico. Condor 54:163-168. Ridgway, R. 1904. The birds of North and Middle America. Part 3. U.S. Nat. Mus. Bull. 50. 801. pp. Small, A. 1974. The birds of California. Winchester Press, N.Y. 310 pp. Tatschl, J. L. 1967. Breeding birds of the Sandia Mountains and their ecological distributions. Condor 69:479-490. Van Rossem, A. J. 1936. Birds of the Charleston Mountains Nevada. Pacific Coast Avifauna No. 24. 65 pp. Weydemeyer, W. 1975. Half-century record of the breeding birds of the Fortine area, Montana: Nesting data and popu- lation status. Condor 77:281-287. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. 6. 39 pp. >£: o SONG SPARROW Melospiza melodia I TAXONOMY A. Type description AOU (1957) Melospiza melodia melodia (Wilson); Fringilla melodia Wilson, Amer. Orn. , vol. 2, 1810, p. 125, pi. TE, fig. 4. (Canada to Georgia = Philadelphia, Pennsylvania.) Melospiza melodia montana Henshaw; Melospiza fasciata montana Henshaw, Auk, 1, no. 3, July 1884, p. 224. (Fort Bridger, Utah f}= Wyoming} . ) Melospiza melodia merrilli Brewster; Melospiza fasciata merrilli Brewster, Auk, 13, no. 1, Jan"! 189b, p~ 4b. (Fort Sherman, Idaho.) Melospiza melodia fisherella Oberholser, Proc. Biol. Soc. Washington, 24, no. 49, Dec. 23, 1911, p. 251. (Honey Lake, near Millford, California.) Melospiza melodia cooperi Ridgway; Melospiza fasciata cooperi Ridgway, Auk, lb, no. 1, Jan. 1899, p. 35. (San Diego, California. ) Melospiza melodia saltonis Grinnell, Univ. California Publ. Zool. , 57 no. 3, Apr. T", T909, p. 268. (One mile southeast of Mecca, "Colorado Desert, California.) B. Current systematic treatments AOU (1957) places Melospiza melodia in the Order Passeri- formes, Family Fringiilidae, and lists 31 races. Linsdale (1928) suggests that Melospiza and Passerella properly belong in the same genus, as does Paynter (wI9b4/) , wHile Parkes (1954) maintains that they should be separate. C. Synonomies of scientific nomenclature AOU (1957) lists the synonomies as above. Grinnell and Miller (1944), M. m. montana - M. m. fall ax, part; M. m. yirginis; M. m. fisherella, part; M. m. fisherella - Melospiza fallax,~M. ruTina, M. fasciata, M. cinerea faliax~ M. m. maiiliarai,~FassereTla melodia Tisherella: M. m. merrilli - M. fasciata guttata, M. f. ingersolli, M. m. Tngersolli, H. cinerea merrilli, H. m. morphnal M. m. cooperi - ZonotrichiaTasciata, M. heermanni , M. m. heermanni , M. fasciata heermanni, M. f. samueiis, H. T. grammea, MT f . cooperi7 M. cinerea cooperi, M. mT santaecrucis: M. m. saltoni's - M. fallax, M. m. fallax, M. cinerea falTax. • Melospiza melodia (con't.) D. Synonomies of vernacular nomenclature Grinnell and Miller (1944) list the following as synonomies for the Song Sparrow: Rocky Mountain Song Sparrow, Modoc Song Sparrow, Virgin River Song Sparrow, Mountain Song Spar- row, Oregon Song Sparrow, Heerman Song Sparrow, Merrill Song Sparrow, Desert Song Sparrow, Modesto Song Sparrow, Tehama Song Sparrow, Calif ornian Song Sparrow, Samuel's Song Sparrow, Santa Barbara Song Sparrow, Arizona Song Sparrow, Western Song Sparrow, Salton Sink Song Sparrow. II DESCRIPTION A. External morphology of adults Baird et al . (1905) describe the species as a whole as fol- lows: general tint of upper parts rufous and distinctly streaked dark-brown, and ashy-gray. The crown is rufous, with a superciliary and median stripe of dull gray, the former lighter; nearly white anteriorly, where it sometimes has a faint shade of yellow, principally in autumn; each feather of the crown with a narrow streak of black forming about six narrow lines. Interscapulars black in the center, then rufous, then pale grayish on the margin, these three colors on each feather very sharply contrasted. Rump grayer than upper- tail coverts, both with obsolete dark streaks. There is a whitish maxillary stripe, bordered above and below by one of dark rufous-brown, and with another from behind the eye. The underparts are white; the jugulum and sides of body streaked with clear dark-brown, sometimes with a rufous suffusion. On the middle of the breast these marks are rather aggregated so as to form a spot. No distinct white on tail or wings. Specimens vary somewhat in having the streaks across the breast more or less sparse, the spot more or less distinct. In autumn the colors are more blended. Peterson (1961): "Note the heavy breast streaks confluent into a large central spot. Many subspecies vary in color and size; those of arid sections are paler; those in humid regions darker. Oberholser (1974) gives measure- ments for the races. Marshall (1948b) gives detailed descriptions of adults for the races occurring around the San Francisco Bay region. B. External morphology of subadult age classes Baird et al. (1905) describes young as having upper parts paler, the streaks more distinct; the lines on the head scarcely appreciable. The underparts are yellowish; the streaks narrower and more sharply defined dark brown. Peterson (1961): "...more finely streaked, often without central spot." Melospiza melodia (con't.) C. Distinguishing characteristics Intraspecific - Bent (1968): "montana is similar to melodia, but wing, tail and tarsi averaging longer, bill smaller and relatively more slender, coloration grayer. Merrilli is very similar to montana but slightly darker and more uniform above, with grayish edges to the interscapulars and scapulars less strongly contrasted with the darker mesial streaks. Fisherella. . .similar to heermanni but larger; upper surface paler, less rufuscent"; streaks on lower parts less blackish. Fisherella differs from montana in its darker upper parts, more blackish brown streaks of under surface, heavier bill, and shorter wing. Cooperi . . . similar to heermanni but slightly smaller and coloration much lighter and grayer; prevailing color of the back, etc., grayish olive, the back broadly streaked with black streaks with little if any, rusty external suffusion. Saltonis. . .resembling fallax but very much paler throughout , the ground color being white ventral ly and ashy dorsally, with streaking of pale hazel; superciliary stripe wholly white; general size much less than montana. Robbins et al. (1966): "Geographic races vary from rusty to gray and light to dark." Wolf son (1955) describes some races on the Pacific coast and their variation. Marshall (1948a & b) describes race variation in California. Interspecific - Peterson (1961): "Savannah Sparrow often shows yellow average, has pinker legs, shorter notched tail. Fox Sparrow is larger, more- heavily marked." Robbins et al. (1966) add that it lacks a yellow or buffy color. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution AOU (1957) Melospiza melodia, "Aleutian Islands, southern Alaska, southern Yukon, southern Mackenzie, northern Saskatchewan, northern Manitoba, northern Ontario, central Quebec, and Newfoundland south to south-central Baja Calif- ornia, northern Sonora, Michoacan, and Puebla; and to north- ern New Mexico, northeastern Kansas, northern Arkansas, southeastern Tennessee, northern Georgia, and northwestern South Carolina. M. m. montana: "Breeds from northeastern Oregon, central western Idaho, and north- central Montana, south to eastern Nevada, southwestern Utah, central eastern Arizona, and northern New Mexico." • M. m. merrilli: "Breeds from southern interior British Columbia and southwestern Alberta south to eastern Wash- ington, east of the Cascade Range, northern Idaho, and north- western Montana." Melospiza melodia (con't.) M. m. fisherella; "Breeds from northeastern Oregon, east of the Cascade Range and west of the Blue Mountains, and extreme southwestern Idaho south to south-central Oregon, north-central and central eastern California, and western Nevada." M. m. cooperi : "Resident in the coastal districts of southern California from Santa Cruz County southward to northern Baja California, as far as at lat. 30° N. ; east to streams pene- trating Mohave and Colorado deserts. f M. m. saltonis; "Resident in lower Colorado River Valley Th extreme southern Nevada, southeastern California, western Arizona, northwestern Baja California, and northwestern Sonora, extending northwest through Imperial Valley of Calif- ornia. Casual is desert area of southeastern California, south- central Arizona, and northwestern Sonora. Bent (1968), M. m. montana: "Northeastern Oregon and north- central Montana to southeastern California, northern Sonora, central Chihuahua, and western Texas." M. m. merrilli: "Southern interior British Columbia and southwestern Albert south to southern California, southern Utah, and northern New Mexico." M. m. fisheri: "Northeastern Oregon and southwestern Idaho south to southern California." M. m. cooperi : "The San Diego Song Sparrow is resident in the coastal districts of southern California from Santa Cruz County southward to northern Baja California; east to streams penetrating Mohave and Colorado Deserts." M._m. saltonis: "The Desert Song Sparrow is resident in "the lower Colorado Valley in extreme southern Nevada, south- eastern California, western Arizona, northwestern Baja California, and northwestern Sonora, extending northwest through Imperial Valley, California." Phillips (1964) list montana, saltoni, uddi, fisherella, merrilli and ruf ina as occurring in Arizona. Gabrielson and Jewett (1940) say that fallax merges into fisherella as you go east in Oregon. B. California distribution Grinnell and Miller (1944), M. m. montana: "Known princi- pally from Death Valley, Inyo County, and Colorado River Valley south to Fort Yuma, Imperial County; recorded also from Riverside County." v- Melospiza melodia (con't.) M. m. fisherella; "Summer resident in northern interior and eastern sections, and on considerable numbers present there throughout the year. Partial migration in late September and October accounts for appearance of winter visitants to southward and westward. As breeding, Great Basin region from Oregon line southward along eastern flank of Sierras through Owens Valley, and westward through lower mountains and valleys, exclusive of coastal belt, from Klamath River Valley and Shasta Valley south to upper Trinity River System and in Sacramento drainage to Tehama County." M. m. merrilli: "Chiefly Sacramento Valley, northern San Joaquin Valley, and surrounding foothills, but recorded also from lower and middle elevations in State, generally from Oregon line south to Mohave Desert and Los Angeles County, exclusive of northern coastal strip." M. m. cooperi: "Valleys of coast ranges from southern Monterey County southward, and Pacific slopes of southern California south to Mexican boundary; extends eastward across desert divides into Mohave drainage and to streams on east side of San Jacinto Mountains of San Diego County." M. m. saltonis: "Valley of Colorado River from Nevada line to Mexican boundary and waterways of Imperial Valley north to vicinity of Sal ton Sea in Imperial and Riverside Counties, Twice recorded as a vagrant in the Mohave-Inyo region." Grinnell (1928) discusses the distribution of cooperi, cor onator ium , saltonis and rivularis in Baja California. Marshall (,1948a! says there are eleven races breeding in California, and no two of them occur together during the breeding season. C. California desert distribution Grinnell and Miller (1944) list montana as occurring in Inyo, Imperial and Riverside Counties. Fisherella occurs in Owens Valley, Klamath River Valley, upper Trinity River System. In winter it is found on the western part of the Mohave desert, rarely to Coachella Valley. These two races are not sharply contrasted in the western part of the Great Basin. Merrilli occurs in the Mohave desert, Los Angeles County, Inyo and San Bernardino Counties. Cooperi extends into the Mohave River drainage and to streams on east side of San Jacinto Mountains, and mountains of San Diego County. Records from San Bernardino, Riverside, San Diego and Los Angeles Counties. Saltonis is found in the Colorado River Valley and waterways in Imperial Valley north to vicinity of Sal ton Sea in Imperial and Riverside Counties. Twice re- corded as a vagrant in Mohave- Inyo region. Records from Riverside, San Bernardino, Imperial and Inyo Counties. Melospiza melodia (con't.) Willett (1951) only lists saltonis as being a resident of the California desert. "Resident of watered sections of Colorado River and Imperial Valleys, north to Sal ton Sea." D. Seasonal variations in distribution AOU (1957), M. m. montana : "Winters throughout the breeding range and south to southeastern California, northern Sonora, central Chihuahua, and western Texas; east casually to western Nebraska, western Kansas, and western Oklahoma." M. m. merrilli : "Winters from southern interior British Columbia and northwestern Montana west to western Washington and south to southern California, southern Nevada, southern Utah and northern New Mexico. Casually to southern Arizona and northern Sonora." M. m. fisheri: "Winters throughout breeding range south to western and southern California; rarely to northern Sonora and southern Arizona." M. m. cooperi: Winters throughout breeding range. M. m. saltonis: Winters throughout breeding range. Dawson (1923): "California Song Sparrows are sedentary save in the territory east of the Sierras, where increased altitudes and lower temperatures enforce evacuation in winter." Small (1974): "Common resident but birds of Mountains and Great Basin move to lowlands for winter." Marshall (1948a) describes the more northern races as being migratory. IV HABITAT A. Biotopic affinities Grinnell and Miller (1944) report Song Sparrows breeding in thickets arrowweed, and willows and reeds at the edges of ditches and river courses. Life- zones in summer, Lower Sonoran, Upper Sonoran and Transition. In general they favor riparian growth and damp places, freshwater marshes and garden shrubbery. Reported tule beds and cattails. Saltonis has occasionally been noted in mesquite thickets at some distance from water. Baird et al . (1905): "The birds are found in almost any cultivated locality where the grounds are sufficiently open. They prefer the edges of open fields, and those of meadows and low grounds, but are rarely found in woods or in thick bushes, except near their outer edges. Melospiza melodia (con't.) } Bent et al . (1968): "...water-edge vegetation, whether it be marshes around mountain lakes,.... in stream-side willows, ...or in boggy areas of cultivated fields and meadows... clumps of dead tule...into sagebrush. . .dense thickets 6 to 10 feet high along open water." Peterson (1961): "Thickets, brush, marshes, roadsides, gardens, seabeaches." Small (1974): "Streamside thickets, tangles, weed thickets, thickets of willows and reeds at edges of watercourses, marshes, lake borders, brushpiles, gardens, shrubs, edges of marshes." Phillips, et al. (1964), for song sparrows in Arizona: "Locally common resident of reed- sedge-brush types along major permanent rivers... and on permanent brush-lined streams. Rather common winter resident locally at reedy ponds, brushy streams, and farmlands with brushy, weedy edges." They refer to three types of Song Sparrows by biotopic affinity (1) saltonis, fallax - desert, (2) montana, fisherella, juddi - mountain, (3) merrilli, rufina - northwest. Marshall (1948a): "...is a characteristic inhabitant of vegetation growing in wet places..." Evidentally fisherella can forage in drier brush than some of the other races. B. Altitudinal range k Grinnell and Miller (1944) - From near sea level up to 8,000 feet. Bent et al. (1968) - From near sea level to as high as 9,000 feet. C. Home range size Marshall (1948a) - 2/3 acre per pair roughly. He goes on to describe reasons for variation in range size which are generally related to food availability. Nice (1931b) has similar data. Suthers (1960) gives a range of 0.30 to 0.65 acre for territory size. D. Territory requirements Perch sites Courtship and mating sites Nest sites - Grinnell and Miller (1944): "Nests are placed in the vegetation above the mud which marks flood level." Baird et al. (1905): "They nest naturally on the ground," and in bushes above the ground. Bent et al. (1968): "Ground nests appear to be the commonest and are built in grass, alfalfa, in hollows under sage and willows, among ferns under fallen trees. Melospiza melodia (con't.) E. Special habitat requirements <-g0 Grinnell and Miller (1944): "The presence of water is essen- tial, coupled with cover." Phillips et al. (1964) state that south-central Arizona Song Sparrows have led a pre- carious existence, depending on water as they do. Marshall (1948a) gives detailed descriptions of habitat used by Song Sparrows in California. Two of the most important factors are moisture and light. Whitmore (1977) discusses habitat partitioning in some passerines saying that song sparrows are high shrub density species with little canopy cover and moderate ground cover. F. Seasonal changes in habitat requirements Oberholser (1974) says that Song Sparrows appear restricted in habitat use during migration, using cattails, tall grass or weed patches, and bushes growing near streams or lakes. V FOOD A. Food preferences Baird et al. (1905) - insects, caterpillars, larvae, moths. Bent et al. (1968) give estimated plant food consumption as 60% of total diet. Oberholser (1974) describes Song Sparrows as eating varied food depending on their location; crustaceans, mollusks, seeds. B. Foraging areas Grinnell and Miller (1944): "The birds forage short distances out into grassy or weedy places and about root tangles and piles of wood. ' Bent et al. (1968) report them foraging along open water often with their feet in the water. C. Foraging strategies Oberholser (1974) describes Song Sparrows as being the most plastic passerine species in reference to feeding behavior. Marshall (1948a) says that he has never seen them eating seeds off a plant but apparently they must wait for the seeds to fall to the ground. Nice (1940) describes anting in Song Sparrows. D. Feeding phenology Oberholser (1974): "Especially in warm months, it gleans beetles, grasshoppers, crickets, caterpillars, and ants." E. Energy requirements Melospiza melodia (con't.) ^"i REPRODUCTION A. Age at first breeding B. Territorial behavior Nice (1934): "Some resident males begin to proclaim their territories in late January or early February, according to the weather." Nice (1936c) reports song sparrows in Ohio to be very "sessile" on territories. The male chooses the territory. The female returns to her previous nesting site or as near as possible. Nice (1931a) in a paper on song sparrows returning to breeding grounds says that males go directly to their territories. C. Courtship and mating behavior Martin (1977) discusses the functional aspects of song in the Fox and Song Sparrows. Nice (1933c) describes mate fidelity in song sparrows in Ohio. D. Nesting phenology Bent et al. (1968) report the breeding season to begin about 5 February and end about 5 July. Oberholser (1974) says that ^ females commonly raise three broods a year. Nice (1931a) W gives arrival dates in spring as 8 February to 26 March. Nice (1931b): "...nesting began in mid-April. E. Length of incubation period Nice (1940) - 13 days. F. Length of nestling period G. Growth rates H. Post-breeding behavior Oberholser (1944) reports that Song Sparrows seldom sing on their southern wintering grounds. Nice (1934) says the male usually indulges in singing on his territory after the molt in the fall. VII POPULATION PARAMETERS A. Clutch size Baird et al. (1905) - 4 to 5. Bent et al. (1968) - 3.69 mean. Peterson (1961) - 3 to 5. Gabrielson and Jewett (1940) - 4 to 5. Nice (1933b) - 1 to 5. 10 Melospiza melodia (con't.) B. Fledging success Nice (1933b): "In 1930 the numbers of young fledged per pair by 15 pairs that survived the season were as follows: 0,2,2,3,3,3,4,4,4,4,5,6,7,7,10; an average of 4.3 per pair. She calculated 3.2 young raised per successful nest over a 3-year period. C. Mortality rates per age class Nice (1933a) gives mortality for eggs and young in 3 years. Nice (1933c) says that mortality of adult males and females is very high each year. Nice (1931b): "Mortality during the 14 to 18 days of parental care after the young leave the nest is hard to keep track of... 3 broods were wiped out... but at least some of 19 broods were reared to independence." D. Longevity Kennard (1975) gives the oldest banded song sparrow as 10 years 4 months. E. Seasonal abundance Nice (1933a): "It is possible that the weather in October may have something to do with some of the birds staying or leaving." F. Habitat density figures Bent et al. (1968): "Population density was approximately 3 individuals per 10 acres." Wolf son (1955) describes an effective breeding unit as an area of about 400 meters' radius and about 150 individuals. Nice (1931a) presents maps of territories for an area in Ohio. Nice (1931b) had 64 pairs living on 50 acres in Columbus, Ohio. VIII INTERSPECIFIC INTERACTIONS A. Predation Nice (1931b) lists dogs, cats and rats as nest predators. She also saw a Ring-necked Pheasant empty a nest. B. Competition Marshall (1948a) reports that habitat is shared in winter with White-crowned and Lincoln Sparrows. Gorton (1977) found song sparrows to be intensely intraspecif ically terri- torial. 11 Melospiza melodia (con't.) P C. Parasitism Friedmann et al. (1977) list these records of parasitism by the cowbird from sets of eggs at the Western Foundation of Vert. Zool.: M. m. montana - 2 sets; M. m. cooperi - 16 sets; M. m. saltonis - 5 sets; M. m. fTsherella - 4 sets. They report the Song Sparrow is a common and good host. Nice (1933b) notes cowbird parasitism in some song sparrow nests. IX STATUS A. Past population trends Dawson (1948) describes fossil specimens of M. melodia found at Rancho La Brea. B. Present population status Grinnell and Miller (1944) believe that the development of irrigation has increased the total population of saltonis in the last 30 years. C. Population limiting factors P Dawson (1923): "A young Song Sparrow is the choice morsel for everything that preys--cats, skunks, weasels, chipmunks, foxes, hawks, crows, magpies, jays, snakes." D. Environmental quality: adverse impacts E. Potential for endangered status 12 Melospiza melodia (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Baird, S. F. , T. M. Brewer and R. Ridgway. 1905. A history of North American birds. Vol. 2. Little, Brown, and Co., Boston. Bent, A. C. and collaborators. 1968. Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows, and allies. Part Three. U.S. Natl. Mus. Bull. No. 237. Dawson, W. L. 1923. The birds of California. Vol. 1. South Moulton Co., Los Angeles. Dawson, W. R. 1948. Records of fringillids from the pleisto- cene of Rancho La Brea. Condor 50:57-63. Eberhardt, C. and L. F. Baptista. 1977. Intraspecif ic and interspecific song mimesis in California song sparrows. Bird-Banding 48:193-205. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the para- sitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Gabrielson, I. N. and S. G. Jewett. 1940. Birds of Oregon. Oregon State College, Corvallis, 650 pp Gorton, R. E. , Jr. 1977. Territorial interactions in sympatric song sparrow and Bewick's wren populations. Auk 94:701-708. Grinnell, J. 1928. A distributional summation of the ornithology of lower California. Univ. of California Publ. Zool. 32: 1-300. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna. No. 27. 608 pp. Harris, M. A. and R. E. Lemon. 1974. Songs of song sparrows: reactions of males to songs of different localities. Condor 76:33-44. Hoyt, S. F. 1961. Nest-building movements performed by juvenile song sparrow. Wil. Bui. 73:386-387. Kennard, J. H. 1975. Longevity records of North American birds. Bird-Banding 46:55-73. 13 Melospiza melodia (con't.) Linsdale, J. M. 1928. The species and subspecies of the fringillid genus Passerella Swainson. Condor 30:349-351. Marshall, J. T. , Jr. 1948a. Ecological races of Song Sparrows in the San Francisco Bay region. Part I. Habitat and Abundance. Condor 50:193-215. Marshall, J. T. , Jr. 1948b. Ecological races of Song Sparrows in the San Francisco Bay region. Part II. Geographic variation. Condor 50:233-256. Martin, D. J. 1977. Songs of the Fox Sparrow. I. Structure of song and its comparison with song in other emberizidae. Condor 79:209-221. Nice, M. M. 1930. The technique of studying nesting song sparrows. Bird-Banding 1:177-181. Nice, M. M. 1931a. Returns of song sparrows in 1931. Bird- Banding 2:89-98. Nice, M. M. 1931b. Survival and reproduction in a song sparrow population during one season. Wil. Bull. 43:91-102. Nice, M. M. 1933a. Migratory behavior in song sparrows. Condor 35:219-224. Nice, M. M. 1933b. Nesting success during three seasons in a song sparrow population. Bird-Banding 4:119-131. Nice, M. M. 1933c. Relations between the sexes in song spar- rows. Wil. Bull. 45:51-59. Nice, M. M. 1934. Song sparrows and territory. Condor 36: 49-57. Nice, M. M. 1937. Studies in the life history of the song sparrow I. A population study of the song sparrow. Trans. Linn. Soc. , N.Y. 4:1-247. Nice, M. M. 1939. What determines the time of the song sparrow's awakening song? Proc. of the IX International Ornithological Congress, Roven. Nice, M. M. 1940. Anting by the song sparrow. Auk 57:520-522. Nice, M. M. 1943. Studies in the life history of the song spar- row III. The behavior of the song sparrow and other passerines. Trans. Linn. Soc, N.Y. 6:1-328. Nice, M. M. 1953. The question of ten-day incubation periods. Wil. Bull. 65:81-93. 14 Melospiza melodia (con't.) Oberholser, H. C. 1974. The bird life of Texas. Vol. 2. Univ. of Texas Press, Austin. Parkes, K. C. 1954. Notes on some birds of the Adirondack and Catskill mountains, New York. Ann. Carnegie Mus. 33:149- 178. Paynter, R. A. 1964. Generic limits of Zonotricha. Condor 66:277-287. Peterson, R. T. 1961. A field guide to western birds. Second Edition. Houghton Mifflin, Co., Boston. 366 pp. Phillips, A., J. Marshall, G. Monson. 1964. The birds of Arizona. Univ. of Arizona Press, Tucson. 212 pp. Phillips, A. R. and R. W. Dickerman. 1957. Notes on the song sparrow of the Mexican plateau. Auk 74:376-382. Robbins, C. S. , B. Bruun and H. S. Zim. 1966. Birds of North America. Western Publ. Co., Wisconsin. 340 pp. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Suthers, R. A. 1960. Measurement of some lake- shore territories of the song sparrow. Wil. Bull. 72:232-237. Whitmore, R. C. 1977. Habitat partitioning in a community of passerine birds. Wil. Bull. 89:253-265. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna. No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp Wolfson, A., Ed. 1955. Recent studies in avian biology. Univ. of Illinois Press, Urbana. 479 pp. 9 I TURKEY VULTURE Cathartes aura I TAXONOMY A. Type description AOU (1957), Cathartes aura teter Friedmann, Proc. Biol. Soc. Washington, 46, Oct. 2TT, H)33, p. 188. (Riverside, California. J B. Current systematic treatments AOU (1957) recognizes 3 subspecies of C. aura; 4 species in the Genus Cathartes, Family CathartTdae, Super family Cathartoidea, suborder Cathartae, Order Falconiformes. Taverner (1926) recognizes one subspecies, C. a. septen- trionalis, the Northern Turkey Vulture, in the Family Cathartidae, Suborder Sarcorhamphi, Order Raptores. Brown and Amadon (1968) don't recognize teter, but put the western United States subspecies under C. a. aura. Wetmore (1964) calls teter C. a. meridionalis, comBining the two as one. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Western Turkey Vulture, C. aura; Rhinogryphus aura; Oenops aura; C. aurea ; C. a. septen- trionalis. Wetmore (1964) : C. a. meridionalis. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944): Turkey Vulture; Turkey Buzzard; Red-headed Turkey Vulture; Red-headed Vulture; Northern Turkey Vulture; May (1935): Carrion Crow, John Crow, Red- headed Buzzard. II DESCRIPTION A. External morphology of adults Dawson (1923): Head and neck all naked, livid crimson; above a lustrous black with purple, varied grayish brown edgings of feathers; plumage changing below to more uniform sooty brown, lustrous only on the breast; wing-quills and retrices light to dusky below, with whitish shaft; primaries deeply emarginate; iris brownish gray; bill dull white; cere bright red. Dawson (1923) also give measurements. Taverner (1926) feet resemble those of a chicken rather than a hawk; claws are blunt and foot is poorly adapted for seizing or holding prey. Peterson (196!) sexes alike; 2- toned blackish wings (flight feathers lighter than wing linings) ; nearly eagle size; soars with wings slightly above Tiorizontal. Cathartes aura (con't.) B. External morphology of subadult age classes Dawson (1923) Similar to adult but dusky on head and neck, with grayish brown feathers; bill blackish. C. Distinguishing characteristics Interspecific - Peterson (1961); diminutive head and slimmer tail distinguish Turkey Vultures from eagles. Brown and Amadon (1968); very similar to Yellow-headed Vulture, dis- tinguished by red, not yellow, head and by darker base of wing in flight. Zone- tailed Hawk has a similar flight profile, but its tail has white bars. Intraspecific - Grossman and Hamlet (1964): Most do not differ noticeably, but populations in the Amazon rain forest are darker; green and bronze- glossed plumage occurs in the Falkland Island race. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957): Breeds from southern British Columbia, central Alberta, Saskatchewan, southern Manitoba, western Ontario, northern Minnesota, and Wisconsin south to southern Baja California, and in the interior of Mexico to Colima, Jalisco, Guanajuato, Michoacan, and Districto Federal; east to eastern Texas. Grinnell and Miller (1944): In summer seen more or less commonly from Mexican line to Oregon line, and from seashore to Nevada line and up to altitudes of 10,000 feet in Sierra Nevada, as on Mount Dana, Tuolumme County. Breeds chiefly in the upper Sonoran Zone. Dawson (1923): North America from the southern portions of the western Canadian Provinces, southwestern Ontario, southern New York, and New Jersey, south to northern Mexico and southern lower California. Phillips et al. (1964) describe the Turkey Vulture as a common summer resident, except in extensive forested areas, in Arizona. In southern Nevada, Gullion et al. (1959) describe the Turkey Vulture as "primarily spring and fall migrants on the desert." B. California distribution of the species Grinnell and Miller (1944): "Sample localities. . .Modoc County; Requa, Del Norte County; Cape Mendocino, Humboldt County; San Francisco Bay area; Mount Diablo, Contra Costa County; 15 miles northeast of San Jose in Alameda County; Yosemite region; Fresno district, Fresno County; Elk Hills, Kern County; Death Valley, Inyo County; Santa Barbara, Santa Barbara County; Whittier, Los Angeles County; Buena Park, Orange County; San Jacinto Mountains; Colorado River Valley." » Cathartes aura (con't.) Dawson (1923): Resident south of the Tehachipe and casually north to Vaca Valley, Solano County. Elsewhere found commonly in spring, summer, fall throughout the State (California), gave in the Boreal Zone. Most abundant in warmer sections, and breeding almost exclusively in Upper Sonoran zone. Small (1974), "length of the state. Breeds throughout the State." C. California desert distribution Grinnell and Miller (1944): Yosemite region; Elk Hills, Kern County; Death Valley, Inyo County. Willet (1951) refers to calurus as a "migrant, probably resident locally," in the southern California desert. D. Seasonal variations in distribution Grinnell and Miller (1944): In winter, only west of the Sierras and at low altitudes; there north to Red Bluff, Tehama County and Ornbaun Springs, Mendocino County. Grinnell (1915): remains throughout winter in small number in the San Diegan district, and north interiorly at least to Vaca Valley, Solano County. Dawson (1923): winters easterly in all except the northern portion of its range, but in the West retiring as far as Nebraska and California. AOU (1957): Winters from California and Nebraska south to Ecuador. One winter record for Vancouver Island. Small (1974), "part of the population is resident and part is migratory. " IV HABITAT A. Biotopic affinities Dawson (1923) and Grinnell (1915); Upper Sonoran Zone. Brown and Amadon (1968) refer to C. aura as a bird of open plains, desert, forest, jungle an3 even high barren desert plateau. Small (1974) "...over open country of mountains, grasslands, deserts, savannahs, and agricultural lands." B. Altitudinal range Grinnell (1915): Breeds chiefly if not altogether in the Upper Sonoran Zone. Dawson (1923): agrees with Grinnell (1915), and adds that the bird is not a high flier. C. Home range size • Cathartes aura (con't.) D. Territory requirements *& Perch sites - Griimell and Miller (1944): When roosting, uses tree with open branch work. Brown and Amadon (1968); "...rather slow in leaving the roost each morning. During the middle of the day there are, except in rainy weather, no vultures near the roost. . .The roost is sometimes shared with Black Vultures. Neither species nests near the roost, as a rule." Prather et al. (1976) report a roost in Virginia containing 13 Black Vultures and 320 Turkey Vultures. Courtship and mating sites - Brown and Amadon (1968); "Both birds may roost in the nesting cavity for some time before the eggs are laid." Nest sites - Grinnell and Miller (1944): prefers shelter of rocks or brush on steep hillsides, or cavities in cliff faces. Dawson (1923): "in hollow trees, stumps, fallen logs, crannies in cliffs; unlined." Taverner (1926); on the ground usually in a hollow log, or under an upturned stump. Brown and Amadon (1968), "eggs are laid in caves, preferably ones with two entrances; in hollow logs or stumps, or on the ground in dense inaccessible briar patches or swamps. Occasionally. . .well above the ground." No real nest is built. m E. Special habitat requirements Brown Tachycineta thalassina (con't.) B. Present population status C. Population limiting factors Franzreb (1976) "A hole-nesting species such as the Violet- green Swallow breeding, later in the season may have diffi- culty in locating suitable nest cavities as most are already occupied by other species... If such sites are in short supply, the number of nest cavities may be an important factor in limiting population densities. D. Environmental quality: adverse impacts E. Potential for endangered status P Tachycineta thalassina (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bent, A. C. 1942. Life histories of North American fly- catchers, larks, swallows, and their allies. U.S. Nat. Mus. Bull. 179. Combellack, C. R. B. 1954. A nesting of Violet-green Swallows. Auk 71:435-442. Dawson, W. L. 1923. The birds of California. Vol. 1. South Moulton Co., San Francisco. Edson, J. M. 1943. A study of the Violet-green Swallows. Auk 60:396-403. Franzreb, K. E. 1976. Nest site competition between Mountain Chickadees and Violet-green Swallows. Auk 93:836-837. Grinnell, J. 1908. The biota of the San Bernardino Mountains. Univ. California Publ. Zool. Vol. 5:1-170. Grinnell, J. and A. H. Miller. 1944. The distribution of birds of California. Pacific Coast Avifauna No. 27. 608 pp. Lasiewski, R. C. and H. J. Thompson. 1966. Field observation of torpidity in the Violet-green Swallow. Condor 68:102- 103. Miller, A. H. 1940. A transition island in the Mohave Desert. Condor 42:161-163. Miller, A. H. 1951. An analysis of the distribution of the birds of California. Univ. California Publ. Zool. No. 50: 531-624. Nichols, W. F. 1938. Some notes from Negit Island, Mono Lake, California. Condor 40:262. Peters, J. L. 1960. Checklist of birds of the world. Vol. 9. Mus. Comp. Zool., Cambridge, Massachusetts, 506 pp. Peterson, R. T. 1961. A field guide to western birds. Hough- ton Mifflin Co., Boston. 309 pp. Ridgway, R. 1904. The birds of North and Middle America. Part 3. Bull. U.S. Nat. Mus. No. 50. Tachycineta thalassina (con't.) Small, A. 1974. The birds of California, Macmillan Co., New York. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Webster, H. , Jr. 1944. A survey of the Prairie Falcon in Colorado. Auk 61:609-616. ( r ■ WESTERN BLUEBIRD Sialia rnexicana I TAXONOMY A. Type description Sialia rnexicana bairdi - AOU (1957) Ridgway, Auk, 11, no. 2, Apr. 1894, pp. 151 and 157. (Camp 110, New Mexico = Cactus Pass, 20 miles east of Kingman, Mohave County, Arizona. ) . Sialia m. occidentalis - AOU (1957) Townsend, Journ. Acad. Sci. Philadelphia, 7, pt. 2, (Nov. 21) 1837, p. 188. (Col- umbia River = Fort Vancouver, Washington.). B. Current systematic treatments AOU (1957) considers this species a member of the avian Order Passeriformes, Family Turdidae (Thrushes, Solitaires, and Bluebirds). Peters (1964) includes Western Bluebirds in the Family Musicapidae, Subfamily Turdinae. He recognized six races of S. rnexicana, including bairdi and occidentalis. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Sialia occidentalis; S. caeruleocollig; S. rnexicana anabelae; Sylvia occiHentalis. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Mexican Bluebird; California Bluebird; Anabel Bluebird; Chestnut-backed Bluebird; San Pedro Bluebird. II DESCRIPTION A. External morphology of adults Ridgway (1907) gives a detailed description of plumages of several races. He describes the species general appear- ance as "Above plain rich blue, brighter. . .on the rump, upper tail-coverts, tail, and outer webs of primaries... the blue gradually fading on abdomen. .. sides of chest and breast and anterior portion of sides chestnut. . .bill black; iris dark brown; legs and feet black." Miller and Stebbins (1964), "A bluebird marked with rust-brown areas on breast and back." Sialia mexicana (con't©) B. External morphology of subadult age classes Ridgway (1907) describes young as plain sooty gray with wing coverts, remiges, and rectrices blue. Wheelock (1920), "Young: Gray, mottled and streaked with white, darkest on upper parts." C. Distinguishing characteristics Interspecific - Peterson (1961), "Similar species: (1) See Eastern Bluebird. (2) Male Lazuli Bunting has white wing-bars. (3) Mountain Bluebird has blue breast." Intraspecific - Ridgway (1907) states that bairdi is "Similar to S. m. occidental! s, but adult male with whole back and scapulars uniform chestnut, producing a large and conspi- cuous dorsal patch." Measurements of both races are given. Miller and Stebbins (1964), "Female with blue and brown areas much duller than in male, the throat often nearly gray." Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) lists the overall range of the Western Bluebird (Sialia mexicana) as "From southern British Columbia and central Montana south through the mountains to northern Baja California, Michoacan, Puebla, and central Veracruz." Sialia m. bairdi - AOU (1957), range "Breeds from southern Nevada, central Utah and Colorado south through the moun- tains to central western and southeastern Arizona, northern Chihuahua, and western Texas. Winters throughout breeding range at lower altitudes; wandering to southeastern Calif- ornia (Little Lake, Victorville, lower Colorado Valley), eastern Sonora, and central Texas." Peters (1964), "Southern Nevada, central Utah, and Colorado south to Arizona, western Texas, northern Sonora, and northern Chihuahua; wintering at lower altitudes in same areas and as far as southeast California." Sialia m. occidental is - AOU (1957), range "Breeds from southern British Columbia and western and central southern Montana south in eastern Oregon, northern Idaho, and northwestern Wyoming, and through the mountains to south- ern California (San Diego, San Bernardino Mountains, Walker Pass) and western Nevada. Winters in breeding range at lower altitudes, rarely north to British Columbia, wandering to southeastern California (Death Valley, Potholes, Twenty- nine Palms), and Santa Catalina and San Clemente Islands. ' Peters (1964), "Southern British Columbia, Montana, eastern Oregon, Idaho, and Wyoming south in the mountains to southern California and Western Nevada; wintering at lower altitudes; wandering to southeast California, Santa Catalina and San Clemente Islands." Sialia mexicana (con't.) P B. California distribution of the species Sialia m. bairdi - Grinnell and Miller (1944), "In summer known only from Clark Mountain, 7300 feet, northeastern San Bernardino Co. In winter, Providence Mountains. . .Colorado River, Needles to Potholes." Sialia m. occidentalis - Grinnell and Miller (1944), "As breeding" entire length of State west of eastern margins of Sierran forests, but including Great Basin plateau south to the vicinity of Lake Tahoe." Small (1974), range in California of S. mexicana (Races combined) — "for breedings length of~"state exclusive of eastern and southeastern deserts; in winter, almost statewide." C. California desert distribution Grinnell and Miller (1944) list Death Valley, Twentynine Palms, Colorado River Valley, Needles, Little Lake, Victor- ville, and Oro Grande as areas of winter occurrence. They conclude that "the winter population in this region now appears to us to be composed chiefly of bairdi; occasional individuals apparently represent occidentalis." In Joshua Tree National Monument, Miller and Stebbins (1964) called this species a "Common winter resident." They listed sev- eral sightings, including: Morongo Valley (April); Little Morongo Canyon (March) ; and Twentynine Palms (November through late March) . Most birds were occidentalis, although bairdi can be expected. Although they do not breed, Willett (1951) described these bluebirds as winter visitants on southern California deserts. Smyth and Coulombe (1971) noted this species during winter at Upper Carrizo Spring, Riverside Co. Wauer (1964) found breeding bluebirds above 9,000 feet in the bristlecone pine association of the Pana- mint Mountains, Death Valley. Grinnell (1914) found occi- dentalis to be a common winter visitor along the lower Colorado River; bairdi not present. Grinnell (1934) noted occidentalis wintering in Death Valley. Gilman (1935) also found this race wintering in Death Valley (Furnace Creek Ranch). Carter (1937) describes wintering flocks of Western Bluebirds at Twentynine Palms, San Bernardino Co., California, from early November to late March. Van Rossem (1911) noted this species wintering near the Sal ton Sea. Lamb (1912) found Western Bluebirds between November and March on the Mohave Desert near Daggett (San Bernardino Co.). In the lower Colorado Valley during winter, Price (1899) described these bluebirds as "Common in the river bottom, feeding largely on the. . .mistletoe." Grinnell (1901) noted several flocks of occidentalis near Barstow, San Bernardino Co., in January. Grinnell (1904) found this species wintering near Palm Springs (Palm Canyon) in "great numbers." Near Victorville (Mojave River), Mailliard and Grinnell (1905) described Western Bluebirds during winter as "Abundant along the river bottom where they were feeding largely on mistletoe berries." Sialia mexicana (con't.) D. Seasonal variations in distribution /gj* In California, Grinnell and Miller (1944) found that "Migra- tory movements are irregular as to date and apparently often are local or altitudinal. In many sections these bluebirds are permanently resident." Peters (1964) notes that both bai rdi and occidentalis drop to lower elevations during the winter, wandering onto southeast California deserts. Wintering birds in Arizona were found "somewhat irregularly in farmlands and on the desert wherever mistle- toe occurs." In southwestern California, Willett (1933) found this species breeding to over 10,000 feet; is more widely distributed over lowlands in winter. IV HABITAT A. Biotopic affinities Grinnell and Miller (1944), "In breeding season, the prime requisite is well spaced, broken timber, providing nest sites and an abundance of exposed lookout posts. . .mature, scattered groups of willows and cottonwoods along stream courses; typically open stands of wild walnut and sycamore, and of blue, valley and black oaks; yellow and Monterey pine forests, and even conifers of higher zonal type when displaying the requisite spacing." In California, Small (1974) gives habitat as "open forests of deciduous, coni- ferous, or mixed trees; savannah; edges of riparian wood- lands." In Joshua Tree, Miller and Stebbins (1964) found Western Bluebirds wintering in the pinon belt and in the lower, open desert. Peterson (1961; describes habitat as "scattered trees, open conifer forests, farms." In a montane forest of Colorado, Winternitz (1976) found that Western Bluebirds spent 67% of their time in an aspen-willow woodland, 13% in ponderosa pine, 13% in Douglas fir, and TL in spruce-aspen. B. Altitudinal range Grinnell and Miller (1944), "Altitudes of summer residence range from near sea level... up to 10,600 feet in San Bernardino Mountains." In southern Nevada, Johnson (1965) found this bluebird breeding between 7,500 and 9,200 feet. C. Home range size D. Territory requirements Perch sites - Grinnell and Miller (1944) stated that exposed limbs and dead trees are favorite perch sites. Grinnell and Storer (1924), "It ordinarily seeks a perch which will com- mand a wide field of view, as on some upper or outer branch." Sialia mexicana (con't.) Courtship and mating sites - Bent (1964) noted a pair of bluebirds mating while perched next to one another. Nest sites - Peterson (1961) describes nests as "In hole in tree, stub, bird box." Wheelock (1920), "In old wood- pecker holes or in cavities of pine trees, usually rather high." E. Special habitat requirements Grinnell and Miller (1944) found that this species requires areas of well spaced timber along with abundant dead trees or limbs; the presence of mistletoe (berries) may govern local occurrence during winter. F. Seasonal changes in habitat requirements Speaking of bairdi, Grinnell and Miller (1944) found that "In summer, open patches of white fir, interspersed with pirion, on mountain slopes. In winter, yucca, sagebrush and creosote bush associations." Peterson (1961) found that during winter, this species moves from conifer forests out onto semiopen terrain, brush, and deserts. Wheelock (1920), "He is a resident throughout the foothills and lower mountains, coming down to the valleys in winter." V FOOD A. Food preferences In Joshua Tree, Miller and Stebbins (1964) noted wintering birds feeding on insects and mistletoe berries. Martin et al. (1961) describe animal food as--Grasshoppers con- stitute the largest and most regular item, followed by caterpillars, beetles (particularly ground beetles), and ants Plant food includes- -grape, mistletoe, elderberry, and fig. In California, Wheelock (1920) found "crickets, moths, grasshoppers, caterpillars, ants, and weevils form his diet, varied with fruits. B. Foraging areas Grinnell and Miller (1944) found this species feeding in "open patches of grassy, meadowy, or even rocky ground." Pitelka (1941) watched Western Bluebirds feeding "on a south-facing, open, grassy slope" in California. • Sialia mexicana ( con ' t . ) C. Foraging strategies Grinnell and Miller (1944) noted that feeding is "by the hovering method or from scattered bush tops or weed stalks... some flycatching of insects is indulged in." Miller and Stebbins (1964) noted that "these bluebirds forage on in- sects, dropping down to the desert floor." Wheelock (1920) noted that 'This bluebird, has the habit of darting down from a perch for insects, and often hunting through the grass for them..." Pitelka (1941) noted Western Bluebirds hovering and soaring for food items. D. Feeding phenology Grinnell and Miller (1944), "Although most of the food in summer is taken from the ground or the grass tops, some flycatching of insects is indulged in. In winter, mistle- toe berries commonly are taken..." Martin et al. (1961) found that animal matter makes up the largest part of this bluebird's diet. They found that plant material accounts for 4% of the diet in summer, 21% in fall, 267o in winter, and 0% in spring. Grinnell and Storer (1924) discuss the important role that mistletoe berries play in the diet of wintering bluebirds in California--"In summer the birds live chiefly upon insects. . .But in the colder months of the year, when insects are relatively scarce, the bluebirds ...gave their attention to berries." E. Energy requirements During winter on the California desert (Joshua Tree) , Miller and Stebbins (1964) noted bluebirds drinking from tanks and taking moist food. Smyth and Coulombe (1971) noted the frequent drinking at springs in the California desert during winter by Western Bluebirds. VI REPRODUCTION A. Age at first breeding B. Territorial behavior Bailey and Niedrach (1965) found that in Colorado, Western Bluebirds seldom show aggressive behavior towards swallows, chickadees > and nuthatches, even though they often nest in the same tree as the bluebirds. C. Courtship and mating behavior Bent (1964) gives a brief account of courtship behavior, in which both male and female mounted one another. e I Sialia mexicana (con't.) D. Nesting phenology In California, Wheelock (1920) gave the breeding season as April through June. Bent (1964; gave California egg dates as "104 records, April 4 to June 20; 58 records, May 2 to May 31, indicating the height of the season." E. Length of incubation period Bent (1964) found that "The period of incubation does not seem to have been definitely determined. .. similar to... the Eastern Bluebird (about 12 days)." F. Length of nestling period Bent (1964) could not find reference to the nestling period of Western Bluebirds, but felt that it was similar to that of Eastern Bluebirds (15-18 days). G. Growth rates H. Post-breeding behavior Grinnell and Storer (1924) noted an upward altitudinal shift in the fall (Yosemite). Flocks form by September ^ which include both adults and immatures, numbering from ™ 6 to 25 individuals. In northern California, Grinnell et al. (1930) noted that "Western Bluebirds were observed in small groups, through the winter and as late in the spring as the middle of April." VII POPULATION PARAMETERS A. Clutch size Peterson (1961), "Eggs (4-6; 8) pale blue." Bent (1964) gives a range of 3 to 8 eggs per clutch, with sets of 4, 5, and 6 being the most common. B. Fledging success C. Mortality rates per age class D. Longevity E. Seasonal abundance In Nevada, Van Rossem (1936) noted that "In fall, bluebirds became more common, an increase which probably resulted from an increase of migrants." Bent (1964) recounted that "This •species is varyingly numerous in lowland areas from late summer to early spring but is usually abundant in the foot- hill areas around Pasadena (Los Angeles Co., California) and in the more open mountain canyons below snow level." Sialia mexicana (con't.) F. Habitat density figures During winter at Joshua Tree on the California desert, Miller and Stebbins (1964) noted flocks of bluebirds as large as 25 to 50 individuals. In Colorado, Winternitz (1976) found an average of 0.6 pairs per 40 ha breeding in montane forests. In a ponderosa pine forest in Arizona, Balda (1969) reported a breeding population of 20 pairs of Western Bluebirds per 100 acreas. Anderson (1970) found a wintering population of 8 to 20 Western Bluebirds per 100 acres in an Oregon white oak forest. Hering (1948) listed 7 pairs of this bluebird nesting on a 75 acre study plot in a Colorado forest. Hosterman and Madding (1978) give a winter density of 40 Western Bluebirds per sq. km. (20/100 acres) in paloverde desert scrub of Arizona. Wilson (1978) found 37 bluebirds per sq. km. (15/100 acres) at Morongo Valley, San Bernardino Co. , California during winter. In a Mojavian desert scrub community, Fees (1976) noted 22 bluebirds per sq. km. (9/100 acres) in winter. Ill INTERSPECIFIC INTERACTIONS A. Predation Page and Whitacre (1975) noted the taking of a Western Blue- bird by a Merlin on the central California coast during winter. Great Horned Owl predation upon Western Bluebirds { in California was recorded by Fitch (1947). Mills (1976) recounts the capture of a Western Bluebird by an American Kestrel. B. Competition Miller and Bock (1972) concluded that interactions between woodpeckers and bluebirds (Monterey Co. , California) sug- gested that competition for nest sites was high in hole- nesters. C. Parasitism Friedmann (1963) felt that this bluebird is a very rare victim of cowbird parasitism. IX STATUS A. Past population trends Grinnell and Miller (1944) called bairdi a "summer resident; rare by reason of greatly restricted breeding habitat along southeastern border. .. Common winter visitant"; and occiden- talis a "Common summer resident over most of the northern and western sections. .. In winter, widespread in lowlands" 9 Sialia mexicana (con't.) (California). Willett (1912) called this species "an abundant breeder in the San Bernardino and San Jacinto Mountains" (California). Sherpardson (1915) felt Western Bluebirds were "much more common lately near the city of Los Angeles than in former years." B. Present population status Small (1974) calls Western Bluebirds "common residents" in California. C. Population limiting factors In Colorado, Winternitz (1976) concluded that because blue- birds must rely on the hole-drilling activities of wood- peckers for nest sites, the nesting activities (or lack thereof) of woodpeckers are potentially limiting to Western Bluebirds. Grinnell (1934) felt that the scarcity of blue- birds wintering in Death Valley was due to the lack of mistletoe berries. D. Environmental quality: adverse impacts In southern California, Ross (1933) felt that removal of dead trees and branches have produced a nesting cavity shortage sufficient enough to force bluebirds to nest on buildings. E. Potential for endangered status 3 10 Sialia mexicana (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. Fifth Edition. American Ornithologists' Union, Baltimore, MD. 691 pp. Anderson, S. H. 1970. The avifaunal composition of Oregon white oak stands. Condor 72:417-423. Bailey, A. M. and R. J. Niedrach. 1965. Birds of Colorado. Vol. 2. Denver Mus. Nat. Hist., Denver, Colorado. Balda, R. P. 1969. Foliage use by birds on the oak- juniper woodland and ponderosa pine forest in southeastern Arizona. Condor 71:399-412. Bent, A. C. 1964. Life histories of North American thrushes, kinglets, and their allies. U.S. Nat. Mus. Bull. 196. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39: 210-219. Fees, D. 1976. 29th winter bird-population study. Am. Birds 30:1064-1065. Fitch, H. S. 1947. Predation by owls in the Sierran foothills of California. Condor 49:137-151. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233. 276 pp. Gilman, M. F. 1935. Notes on birds in Death Valley. Condor 37:238-242. Grinnell, J. 1901. Midwinter birds at Barstow. Condor 3: 70-71. Grinnell, J. 1904. Midwinter birds at Palm Springs, Calif- ornia. Condor 6:40-45. Grinnell, J. 1914. An account of the mammals and birds of the lower Colorado Valley. Univ. California Publ. Zool. 12: 51-294. Grinnell, J. 1934. Further observations upon the bird life of Death Valley. Condor 36:67-72. Grinnell, J., J. Dixon and J. M. Linsdale. 1930. Vertebrate natural history of a section of northern California through the Lassen Peak region. Univ. California Publ. Zool. 35: 1-594. 11 Sialia mexicana (con't.) Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp. Grinnell, J. and T. I. Storer. 1924. Animal life in the Yose- mite. Univ. California Press, Berkeley. 752 pp. Hering, L. 1948. Nesting birds of the Black Forest, Colorado. Condor 50:49-56. Hosterman, G. and R. Madding. 1978. Thirtieth winter bird- population study. Am. Birds 32:37-38. Johnson, N. K. 1965. The breeding avifaunas of the Sheep and Spring ranges in southern Nevada. Condor 67:93-124. Lamb, C. 1912. Birds of a Mohave Desert oasis. Condor 14: 32-40. Mailliard, J. and J. Grinnell. 1905. Midwinter birds on the Mohave Desert. Condor 7:71-77; 101-102. Mansfield, G. S. 1946. Wintering Mountain Bluebirds on the Santa Barbara coast. Condor 48:285. Martin, A. C. , H. S. Zim and A. L. Nelson. 1961. American wildlife and plants. McGraw-Hill Book Co., New York. Miller, A. H. and C. E. Bock. 1972. Natura-1 history of the Nuttall Woodpecker at the Hastings Reservation. Condor 74:284-294. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley 452 pp. Mills, G. S. 1976. American Kestrel sex ratios and habitat separation. Auk 93:740-748. Myers, H. W. 1912. Nesting habits of the Western Bluebird. Condor 14:221-222. Page, G. and D. F. Whitacre. 1975. Raptor predation on wintering shorebirds. Condor 77:73-83. Peters, J. L. 1964. Checklist of birds of the world. Vol. 10. (E. Mayr and R. A. Paynter, Jr., eds.). Mus. Comp. Zool., Cambridge, Mass. 502 pp. Peterson, R. T. 1961. A field guide to western birds. Houghton Mifflin Co., Boston. 309 pp. 12 Sialia mexicana (c n't.) Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. 212 pp. Pitelka, F. A. 1941. Foraging behavior in the Western Blue- bird. Condor 43:198-199. Price, W. W. 1899. Some winter birds of the lower Colorado Valley. Condor 1:89-93. Ridgway, R. 1907. The birds of North and Middle America. Part 4. Bull. U.S. Nat. Mus. No. 50 Ross, R. C. 1933. Western Bluebird nesting in wall tile. Condor 35:73-74. Shepardson, D. I. 1915. Bluebird nesting in low country. Condor 17:206. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Smyth, M. and H. N. Coulombe. 1971. Notes on the use of desert springs by birds in California. Condor 73:240-243. Van Rossem, A. 1911. Winter birds of the Salton Sea region. Condor 13:129-137. Van Rossem, A. J. 1936. Birds of the Charleston Mountains, Nevada. Pacific Coast Avifauna No. 24. 65 pp. Wauer, R. H. 1962. A survey of the birds of Death Valley. Condor 64:220-233. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Wheelock, I. G. 1920. Birds of California. Fifth Editon. A. C. McClurg & Co., Chicago. 578 pp. Willett, G. 1912. Birds of the Pacific slope of southern California. Pacific Coast Avifauna No. 7. 122 pp. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. Wilson, D. L. 1978. Thirtieth winter bird-population study. Am. Birds 32:41. Winternitz, B. L. 1976. Temporal change and habitat prefer- ence of some montane breeding birds. Condor 78:383-393. ^' 9 WESTERN FLYCATCHER Empidonax d. diff icilis I TAXONOMY A. Type description Empidonax d. difficilis - AOU (1957) Baird, in Baird, Cassin, and Lawrence, Rep. Expl. and Surv. R. R. Pac. , vol. 9, 1858, pp. xxx, 198. (West coast; Ft. Steilacoom, Shoalwater Bay, Ft. Tejon = Fort Steilcoom, Washington.) B. Current systematic treatments AOU (1957) lists the Western Flycatcher as a member of the avian Order Passeriformes, Suborder Tyranni, Superfamily Tyrannoidea, and Family Tyrannidae; this species is poly- typic. Hellmayr (1927) gives 5 races of Western Flycatcher, includ- ing E. d. difficilis. Ridgway (1907) states that Western FlycatcRers were once considered a race of the Yellow- bellied Flycatchers (E. f laviventris) . Brodkorb (1949) discusses variations in North American Western Flycatchers, including measurements and plumages. C. Synonomies of scientific nomenclature Hellmayr (1927) gives Empidonax insulicola; E. bairdi perplexus. Ridgway (190/) adds E. pusillus; E. f laviventris aif ficiTTs. Grinnell and Miller (1944J incluHed Tyranni 11a pusilla; E. cineritius. Brodkorb (1949) adds E. d. immodulatus D. Synonomies of vernacular nomenclature Grinnell and Miller (1944) list Little Pewee Flycatcher; Yellow-bellied Flycatcher; Western Yellow-bellied Flycatcher; Baird Flycatcher; San Lucas Flycatcher; Island Flycatcher; Santa Barbara Flycatcher. II DESCRIPTION A. External morphology of adults Ridgway (1907) gives detailed description of plumages; above plain brownish olive, tail grayish brown, wings dusky, two distinct wing bands, a broad orbital ring of yellowish white, mandible wholly yellowish, iris brown, legs and feet dusky brown. Peterson (1961), "Upper parts olive-brown, underparts washed with yellowish, wing-bars whitish, eye-ring white. . .5.5-6 inches." Empidonax dif ficilis (con't.) B. External morphology of subadult age classes "Young similar to adults, but color of upper parts much browner. . .and yellow of under parts paler' (Ridgway 1907). "Young, similar (to adults), but upper parts browner, with wing-bars rusty buff, the sulphur-yellow of belly replaced by dull white" (Wheelock 1904). C. Distinguishing characteristics Interspecific - Ridgway (1907), "...like E. f laviventris (yellow-bellied Flycatcher), but much less greenish; tail longer." Peterson (1961), "Very similar to the other small flycatchers of this group, but underparts more yellowish." Intraspecif ic - Ridgway (1907), sexes alike; adult male - length 127 mm; wing 67.5 mm; tail 57.1 mm and adult female - length 123 mm; wing 64.4 mm; tail 55 mm. Brodkorb (1949) also gives detailed description of intraspecific measure- ments. Johnson (1974) presents an extensive description of molt and age determination in Western Flycatcher. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) gives overall range of E. difficilis as "Breeds from southeastern Alaska, southern British Columbia, west- central Montana, northern Wyoming, and southwestern South Dakota south in the mountains to Baja California, Honduras, and western Texas." The range of E. d. difficilis (AOU 1957) is given as "Breeds from southeastern Alaska, coastal and central southern British Columbia, northern Idaho, and western Montana south to southwestern California (San Clemente Island, San Jacinto) and central western Nevada." Hellmayr (1927), "Western North America, breeding from eastern base of Rocky Mountains and western Manitoba to Pacific coast, north to the Alaskan coast, south to Southern California, New Mexico, and western Texas; wintering in Mexico south to Cape San Lucas, Tres Marias Islands, and Oaxaca. " B. California distribution of the species Grinnell and Miller (1944) describes the California dis- tribution of this species as "In general, nearly entire length and breadth of state. As breeding, more restricted, almost altogether the area west of the main Sierran axis." » 9 Empidonax d. dif ficilis (con't.) Small (1974), "length of state west of Sierra Nevada except for Warner Mountains." Willett (1933) calls this species a resident of canyons in foothills and mesa regions and up to about 6000 feet in the mountains. C. California desert distribution Grinnell and Miller (1944) state that Western Flycatchers range out onto the California deserts during winter, some- times remaining until early June. Small (1974) called Western Flycatchers transients through southeastern deserts of California. Willett (1933) recounts the taking of eggs by W. C. Hanna near San Bernardino (16 May to 16 June). Johnson et al. (1948) found migrating Western Flycatchers during spring (late May-early June) in the Providence Mountains. Grinnell (1914) describes this species as a migrant along the lower Colorado River Valley; does not breed (from Needles southward). Wauer (1962; found several Western Flycatchers during the spring and fall of 1960 at Furnace Creek Ranch, Death Valley (listed as uncommon fall migrants). Carter (1937) reported Western Flycatchers as rare during April and May at Twentynine Palms; not breeding. In the Joshua Tree National Monument, Miller and Stebbins (1964) found Western Flycatchers during spring (2 April to 3 June) and fall (25 August to 15 September) migration. Willett (1951) found this species migrating across the deserts of southern California. D. Seasonal variations in distribution AOU (1957) lists winter range of E. d. difficilis as "... from southern Baja California, rarely northern Sonora, south to southern Sinaloa and southern Oaxaca." Small (1974) gives seasonal status in California as "transient and summer visitor, March to October." Willett (1933) notes that Western Flycatchers are "Found all over lowlands during migration. Rare in winter" throughout their California range. Bent (1963), "The winter range... is in Western Mexico from southern Baja California and southern Sonora south to southern Guerrero and Oaxaca." He gives date of spring arrival in California as 12 March, and latest date of fall departure as 10 October. IV HABITAT A. Biotopic affinities Peterson (1961) describes this species habitat as "moist woods, mixed or conifer forest, canyons, groves." Grinnell and Miller (1944) give extensive summary of habitat require- ments. Characteristically, places that are well shaded by Empidonax difficilis (con't.) tall trees or by steep canyon walls are favored. This species ^* breeding habitat in California was given by Small (1974) as "humid coniferous forest, well- shaded woodlands or forests with running water close at hand, deep, shaded canyons." Johnson et al. (1948) discovered Western Flycatchers in bushes along wash bottoms and ravines in the Providence Mountains, California, during spring migration. Grinnell and Swarth (1913) found this species breeding in small numbers in the high Upper Sonoran and Transition zones of the San Jacinto Mountains, California. In Joshua Tree, Miller and Stebbins (1964) found this species inhabiting pinon, scrub oaks, cottonwoods and willows during migration. B. Altitudinal range Grinnell and Miller (1944) give range as from near sea level up to 6000 feet in southern California; Willett (1933) listed a similar range. Johnson et al. (1948) found this species migrating through the Providence Mountains (Calif- ornia) in spring between 4800 and 7300 feet. Bailey (1906) noted Western Flycatchers breeding at 11,000 feet in New Mexico. C. Home range size D. Territory requirements Perch sites - Grinnell and Miller (1944), "look-out and singing posts, even though up to 40 feet above the ground, are still well beneath the leafy canopy and hence shaded." In southern California, Myers (1911) found that male and female Western Flycatchers used tree limbs as perch sites. Verbeek (1975b) reported perch sites were "almost entirely restricted to the middle and lower interior of trees"; mean perch height was 5.05 m (range = 0.25-17m). Courtship and mating sites - Davis et al . (1963) noted that most pair formation took place within the male's territory. Nest sites - Grinnell and Miller (1944), "A typical nesting locality. . .would thus be the bottom of a foothill canyon or ravine carrying running water at least in spring, with more or less over-arching canopy..." They stated that nests are placed in rock crevices, cavities in trees, or near protected beams or posts under bridges and about buildings. Dawson (1923), "placed in any convenient cranny, but chiefly in well-sheltered niches of banks or up-turned tree roots... near streams." Phillips et al . (1964) state that in the' absence of natural nest sites, such as crannies of banks or tree cavities, the eaves of buildings have proved an acceptable substitute. Davis et al . (1963) give a detailed jfl I Empidonax difficilis (con't.) account of nest sites in Monterey Co., California. "Natural" situations averaged 10.9 feet above ground (0 to 25 feet); all nests were in trees (oaks, sycamores, willows) except one, which was on the shelf of a creek bank. Nests were placed against the trunk of a tree or in a natural cavity. Several nests were also found in buildings. In Texas, Ohlendorf (1974) reported an average tree nest height as being 21.0 + 3.4 feet; over one-half of the nests were in the middle third of these trees. E. Special habitat requirements Peterson (1961) stated that this species requires water and shade in order for it to inhabit an area. In southeast California, the water factor as well as shade limits the range of this species (occurrence of the birds becomes more restricted and spotty) (Grinnell and Miller 1944). VanRossem (1936) felt that the absence of water in much of the mountains of Nevada restricted this species range in that state. In the San Bernardino Mountains of California, Western Fly- catchers are restricted (during breeding) to the lower can- yons of the Pacific slope. F. Seasonal changes in habitat requirements Willett (1933) noted that Western Flycatchers ascend to at least 8000 feet during late summer in California. V FOOD A. Food preferences Prey items taken by this species in Colorado were--Diptera (31%), Coleoptera (25%), Lepidoptera (22%), Hymenoptera 17%), Hemiptera (3%), and Homoptera (1%) (Beaver and Baldwin 1975). Bent (1963) reports that over 99% of the diet is animal matter. Over 38% of the prey items were Hymenoptera, Diptera about 31%. B. Foraging areas Grinnell and Miller (1944), "foraging is conducted beneath the crowns of the trees." In a Colorado aspen-conifer forest, Beaver and Baldwin (1975) found these flycatchers feeding mostly from ground level to 9 m. Myers (1911) noted Western Flycatchers feeding "quite near the nest in a damp place under the bank." Verbeek (1975a) found in a California study that "The Western Flycatcher. .. is strictly fa canopy species, preferring the inner parts of trees." Miller and Stebbins (1964) saw this species "foraging under and about the foliage canopy" at Joshua Tree. » * Empidonax difficilis (con't.) C. Foraging strategies Dawson (1923) describes foraging behavior; the birds select perches bare of vegetation through the middle heights of a forest where they usually "sally flycatch." Oberholser (1914) notes feeding behavior in Texas--MIt f lits. .. through shady openings beneath the tree canopy where it snaps up winged insects from the air and plucks caterpillars from tree trunks." LaRivers (1941) noted that Western Fly- catchers were unable to kill large crickets. Verbeek (1975b) found that this species used the "hawking" method to feed 60% of the time, and "gleaning" about 40"%,. D. Feeding phenology Bent (1963) reported that ladybird beetles made up about 7% of the diet in August, but the average dropped to about 2% for the year. Lepidopterans were not present in the diet for March, but totaled about 7% for the year. E. Energy requirements Beaver and Baldwin (1975) found that Lepidopterans provide Western Flycatchers with 65% of the total dry weight in _ their diet, although these insects account for only 22% i £ of all prey items taken. VI REPRODUCTION A. Age at first breeding Johnson (1974) states that first-year Western Flycatchers are known to breed. B. Territorial behavior Beaver and Baldwin (1975) found that most interspecific territorial disputes between Western Flycatchers and other species take place early in territory establishment. Davis et al . (1963), "The Western Flycatcher has an alert, aggres- sive, snappish nature and reacts to intruders with a swift chase, usually accompanied by threat notes..." C. Courtship and mating behavior Davis et al . (1963) give a detailed account of vocalization and courtship--"Mated males have only a dawn song. Unmated males sing at dawn and during much of the day as well. Song appears to function primarily in mate attraction." & > Em-pi donax difficilis (con't.) D. Nesting phenology Dawson (1923) states that 2 broods are raised in southern California, one elsewhere; season ranges from April to June. Wheelock (1904) gives California season as 1 May to 15 July. Willet (1933) noted Western Flycatchers breeding mostly in late May and early June in California. Davis et al . (1963) found that in California, the nesting cycle begins in late April or early May and second nestings may continue well into July. California egg dates from Bent (1963): 57 records, 6 May to 17 June, indicating height of season. E. Length of incubation period Davis et al. (1963) found that in California "The incubation period is 14 or 15 days, with 15 days the usual period. Incubation is performed by... the female." Rodeck (1947) found that the incubation period lasted as long as 19 days (Colorado). Williams (1942) reported a 15 day period in California. F. Length of nestling period Davis et al . (1963), studying the Western Flycatcher in California, found that "The duration of the nestling period ranged from 14.5 to 17.5 days." G. Growth rates Wheelock (1904) states the young are fed by regurgitation until they are 4 or 5 days old. Davis et al . (1963) gives a detailed description of the nestling period, including feeding and growth rates. They found that at hatching, young weigh about 1.5 g. Young gain 0.6 to 1.5 g per day through the first 9 days of life, after which the rate slows. Average fledging weight is about 10.0 g. H. Post-breeding behavior Swarth (1904), in noting the behavior of this species in Arizona--"Af ter the breeding season they descend the moun- tains to a lower altitude, and after the first of August young and old are fairly abundant in the oaks of the foot- hills, and along the washes as in the spring." In Calif- ornia, Davis et al . (1963) found that the final break-up of a family group is the result of a gradual drifting apart as the young move farther and farther away from the original territory; no young were seen on their parents territory 30 days after fledging. Empidonax difficilis (con't.) VII POPULATION PARAMETERS A. Clutch size Peterson (1961), "Eggs (3-4) spotted." Davis et al. (1963) found that clutch size "consisted of from three to at least five eggs." Bent (1963) reports a clutch as containing 3 or 4 eggs. B. Fledging success In Colorado, Beaver and Baldwin (1975) found that of 28 nestlings, 18 or 64% survived the first week out of the nest. Davis et al. (1963) found in a California study- that "13 young were fledged from five nests, an average of 2.6 fledglings per nest." C. Mortality rates per age class D. Longevity E. Seasonal abundance Davis et al . (1963) noted that in California, "there is a noticeable decrease in numbers by the end of August, followed by occasional records in September and early October .. .records from mid-September on pertain to transients from the North." F. Habitat density figures In California, Grinnell and Miller (1944) concluded that the center of abundance of Western Flycatchers lies within the coast belt along the entire length of the State. In an aspen-conifer habitat in Colorado, Beaver and Baldwin (1975) found breeding densities ranging from 1.2 birds per 10 ha to 6.9 birds per 10 ha. VIII INTERSPECIFIC INTERACTIONS A. Predation Bent (1963) stated that Empidonax flycatchers, like all other small birds, are preyed upon by many predatory birds and mammal s . B. Competition "We have shown that differences in foraging microhabitat are probably not sufficient to prevent competition between E. hammondii and E. difficilis in our study area." (Beaver and Baldwin 1975) (Colorado). Verbeek (1975b), in a study > » Empidonax difficilis (con't.) of Black Phoebes, Western Wood Pewees, and Western Flycatchers in California, showed that "Potential competition among these flycatchers appears to be reduced by interspecific differences in nest site selection, nest height, breeding season, foraging tactics, and the choice of perch sites." C. Parasitism Friedmann (1963), "Unknown as a cowbird host until 1934, the Western Flycatcher appears to be in the process of be- coming a fairly regular victim in California, where the parasite is extending its range." Friedmann et al . (1963) felt, however, that this species choice of nest sites- cliffs and manmade structures — renders it relatively immune from cowbird parasitism (possibly as low as 3.8% of all nests parasitized). Benson and Russell (1934) noted cow- bird parasitism of Western Flycatchers in California. IX STATUS A. Past population trends Grinnell and Miller (1944) called this species "common" throughout its California range. B. Present population status Peterson (1961) called this species "The most frequently encountered Empidonax in most parts of western United States." C. Population limiting factors Grinnell and Miller (1944) felt that the lack of shade and water prevents these flycatchers from expanding into south- east California. D. Environmental quality: adverse impacts E. Potential for endangered status 9 10 Empidonax dif ficllis (con't.) XI LITERATURE CITED American Ornithologists' Union. 1957. Checklist of North American birds. 5th edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Bailey, F. M. 1906. A nest of Empidonax difficilis in New Mexico. Condor 8:108. Beaver, D. L. and P. H. Baldwin. 1975. Ecological overlap and the problem of competition and sympatry in the Western and Hammond's flycatchers. Condor 77:1-13. Benson, S. B. and W. C. Russell. 1934. The cowbird breeds in Berkeley. Condor 36:219. Bent, A. C. 1942. Life histories of North American flycatchers, larks, swallows, and their allies. U.S. Nat. Mus. Bull. 179:1-555. Brodkorb, P. 1949. Variation in the North American forms of Western Flycatcher. Condor 51:35-39. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39: 210-219. Davis, J., G. F. Fisler and B. S. Davis. 1963. The breeding biology of the Western Flycatcher. Condor 65:337-382. Dawson, W. L. 1923. The birds of California. Vol. 2. South Moulton Co., San Francisco. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233:1-276. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the para- sitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Grinnell, J. 1908. The biota of the San Bernardino Mountains. Univ. California Publ. Zool. 5:1-170. Grinnell, J. 1914. An account of the mammals and birds of the lower Colorado Valley. Univ. California Publ. Zool. 12:51-294. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna. No. 27. 608 pp. 11 Empidonax dif ficilis (con't.) Grinnell, J. and H. S. Swarth. 1913. An account of the birds and mammals of the San Jacinto area of southern California. Univ. California Publ. Zool. 10:197-406. Hellmayr, C. E. 1927. Catalogue of birds of the Americas and the adjacent islands. Part 5. Field Mus. Nat. Hist. Zool. Ser. Publ. 242, Vol. 13. Johnson, D. H. , M. D. Bryant and A. H. Miller. 1948. Verte- brate animals of the Providence Mountains area of Calif- ornia. Univ. California Publ. Zool. 48:221-376. Johnson, N. K. 1963. Comparative molt cycles in the tyrannid genus Empidonax. Proc. Intern. Ornithol. Congr. 13:870- 883. Johnson, N. K. 1974. Molt and age determination in Western and Yellowish flycatchers. Auk 91:111-131." LaRivers, I. 1941. The Mormon cricket as food for birds. Condor 43:65-69. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Moore, R. T. 1940. Notes on middle American Empidonaces. Auk 57:349-389. Myers, H. W. 1911. Nesting habits of the Western Flycatcher. Condor 13:87-89. Oberholser, H. C. 1974. The bird life of Texas. Vol. 2. Univ. Texas Press, Austin. Peterson, R. T. 1961. A field guide to western birds. Houghton Mifflin Co. , Boston. 366 pp. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. 212 pp. Rodeck, H. G. 1947. Incubation in the Western Flycatcher. Condor 49:86. Ridgway, R. 1907. The birds of North and Middle America. Part 4. Bull. U.S. Nat. Mus. No. 50. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Storer, T. I. 1914. Return of a Western Flycatcher to a particular locality. Condor 16:144. 12 Empidonax dif ficilis ( con ' t . ) Swarth, H. S. 1904. Birds of the Huachuca Mountains, Arizona. Pacific Coast Avifauna No. 4. 70 pp. Van Rossem, A. J. 1936. Birds of the Charleston Mountains, Nevada. Pacific Coast Avifauna. No. 24. 65 pp. Verbeek, N. A. M. 1975a. Northern wintering of flycatchers and residency of Black Phoebes in California. Auk 92:737- 749. Verbeek, N. A. M. 1975b. Comparative feeding behavior of three coexisting tyrannid flycatchers. Wilson Bull. 87:231-240. Wauer, R. H. 1962. A survey of the birds of Death Valley. Condor 64:220-233. Wheelock, I. G. 1904. Birds of California. A. C. McClurg and Co. , Chicago. 578 pp. Weske, J. S. 1976. Western Flycatcher in Oklahoma. Auk 93: 655-656. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. Williams, L. 1942. Interrelations in a nesting group of four species of birds. Wilson Bull. 54:238-249. < ft WESTERN KINGBIRD Tyrannus verticalis I TAXONOMY A. Type description Tyrannus verticalis - AOU (1957) Mountains , vo 1 . 2, 1823, p. 60. Mts. = near La Junta, Colorado.) B. Current systematic treatments Say, (Ash in Long, Exped. Rocky River, near Rocky • AOU (1957) lists the Western Kingbird as a member of the avian Order Passeriformes, Suborder Tyranni, Superfamily Tyrannoidea, and Family Tyrannidae (Tyrant Flycatchers) ; this species is monotypic. Hellmayr (1927) also lists this species as monotypic. Davis and Webster (1970) feel that the existence of a hybrid Western Kingbird X Scissor-tailed Flycatcher, demonstrates the phylogenetic proximity of the two species. C. Synonomies of scientific nomenclature Ridgway (1907), Muscicapa verticalis ; Laphyctes verticalis. D. Synonomies of vernacular nomenclature Hellmayr (1927), Arkansas Kingbird. Grinnell and Miller (1944) add Arkansas Flycatcher. II DESCRIPTION A. External morphology of adults Ridgway (1907) gives detailed description of plumages; the crown with a large concealed patch of reddish orange; back, wings, add rump plain yellowish gray; tail black, the outer web and shaft of outermost rectrix wholly white: iris brown, legs and feet brownish black. Peterson (1961), "Smaller than Robin, with pale gray head and back, pale yellow belly. .. 8. 5-9 inches." B. External morphology of subadult age class Ridgway (1907) describes the young as being essentially like adults, but without the crown patch, more drab-gray, and yellow of under parts paler. Wheelock (1904), "Young like adults, but crown patch wanting, and wing-coverts edged with buff." Tyr annus verticalis (con't.) ^~ C. Distinguishing characteristics ^9 Interspecific - Peterson (1961), "In this species the black tail has a narrow white edging on each side. . . Ash- throated and Wied's Crested Flycatchers have wing bars, rufous tails." Phillips et al. (1964) calls this species a "paler edition" of the Cassin's Kingbird. Intraspecific - Ridgway (1907) describes the female as similar to the adult male; adult male-- length 206 mm; wing 130.1 mm; tail 93.5 mm and adult female-- length 196 mm; wing 122.3 mm tail 86.9 mm. Ill GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957), range of species - "Breeds from western Oregon, western Washington, east of the coast ranges, southern British Columbia, southern Alberta, southern Saskatchewan, southern Manitoba, and western Minnesota, rarely to southern Wisconsin, southern Michigan, southernmost Ontario, and northwestern Ohio; south to northern Baja California, Sonora, northwestern Chihuahua, southern New Mexico, west-central Texas, northeastern Oklahoma, central eastern Kansas, and rarely, north-central Missouri." Hellmayr (1927), "Western North America, breeding from southern British Columbia, Alberta, and Saskatchewan south to northern Lower California and Chihuahua, east to western Minnesota, western Iowa, central Kansas, and western Texas; wintering from western Mexico to Guatemala..." B. California distribution of the species Grinnell and Miller (1944) describe the California range of the Western Kingbird as "In general, almost entire area of State not heavily forested and below 5000 feet in altitude However, rare, or absent some at migration time, on open deserts and in northern humid coast belt... in migration the species has been recorded from Farallon and most of Santa Barbara Islands." Small (1974) gives range in Calif- ornia as "length of state but absent from northwest coastal forests and southeastern deserts." C. California desert distribution Grinnell and Miller (1944) list important California records, including Death Valley (April) and the Salton Sea (summer). Johnson et al. (1948), while working in the Providence Mtns. of California, found Western Kingbirds most numerous near Cima, San Bernardino County (13 May, in pairs). Grinnell (1914) noted the possible nesting of this species • ^k Tyrannus verticalis (con't.) i near Ehrenberg, Arizona (opposite Blythe, California). Grinnell and Swarth (1913) recount sightings of Western Kingbirds in the San Jacinto area, which include -- Kenworthy, Cabezon, and Banning in June, and Hemet Lake in August. Wauer (1964) found this species breeding in the upper canyons between 3000 and 4000 feet elevation on the Panamint Moun- tains, Death Valley. Carter (1937) noted the Western King- bird at Twentynine Palms during March, April, and May; not breeding. Pierce and Summer (1927) called Western King- birds "an abundant breeder on the desert" near the San Bernardino Mountains. Lamb (1912) found this species nest- ing near Daggett, San Bernardino Co. During the summer, Stevens (1903) noted Western Kingbirds at Twentynine Palms, Needles, Ehrenberg, and several other California and Arizona desert locations. Miller and Stebbins (1964) described this species as "Transient and also summer resident from late March to early September" in the Joshua Tree National Monument. They called Western Kingbirds scarce and local in the Monument, and list several breeding records (Quail Spring). Willett (1951) found this species breeding along the Colorado River and nearby desert regions of southern California. Hollister (1908; found this species nesting near Needles in May. D. Seasonal variations in distribution A0U (1957) states that Western Kingbirds winter in small numbers from the coast of South Carolina to Florida, but chiefly in Middle America from Guerrero and Morelos to northern Nicaragua- -migrates in small numbers to the east coast. Grinnell and Miller (1944) describe Western Kingbirds as "summer residents, late March to early September" in Calif- ornia. Small (1974) gives seasonal status as "common transient and summer visitor, late March to September. . . no satisfactory winter records." Willett (1933) noted that Western Kingbirds usually arrived in California in March and left the state in September. Bent (1963) describes the winter range as "chiefly in the western parts of Central America, north to Sonora, and south to southern Guatemala." He lists date of spring arrival in California as 15 March. IV HABITAT A. Biotopic affinities Peterson (1961) describes the habitat of this kingbird as "Open country with scattered trees, farms, roadsides." Grinnell and Miller (1944), "Dry open situations. .Woodlands must be of far- scattered trees, to harbor this kingbird; oaks, cottonwoods, digger pines and tree-yuccas are attractive, if not growing too thickly." Small (1974) gives California Tyr annus verticalis (con't.) habitat as "open country such as savannah, agricultural lands bordered by trees, plain." Phillips et al. (1964), "This is the common kingbird of the Lower Sonoran Zone." Willett (1933) called this species a common summer resident of lowlands and mesas in California. Grinnell (1914) found that this species prefers cottonwoods along the lower Colorado River. In Washington, Kennedy (1914) found that agriculture, with the associated increase in irrigation, caused an increase in kingbird numbers. B. Altitudinal range Grinnell and Miller (1944), "Altitudes of summer residence extend from below sea level, as near Salton Sea, up to over 6400 feet." Willett (1933) found this species "occasional up to 7000 feet in mountains" of California. Johnson et al, (1948) found Western Kingbirds at elevations between 3300 and 5100 feet in the Providence Mountains, California, during summer. C. Home range size D. Territory requirements Perch sites - Grinnell and Miller (1944) list living and dead trees, derricks, windmills, power poles, and fence- posts as roost sites. Johnson et al. (1948), in the Pro- vidence Mountains area of California, gave perch sites as utility poles, fence posts, Joshua trees, and junipers. Courtship and mating sites - Smith (1966) found that males "have a nest-site-showing display." Bent (1963) recounts several aerial displays performed by male kingbirds. Nest sites - Dawson (1923), "placed at moderate heights in bushes or trees, or, as frequently, on beams and ledges of barns or other outbuildings." Phillips et al. (1964), "nests primarily in broad- leaved deciduous trees, such as cottonwoods and mesquites. It is not adverse to placing its nests on exposed telephone poles." Johnson et al. (1948) found Western Kingbird nests in Joshua trees in the Providence Mountains of California. Quigley (1944) found a pair of Western Kingbirds utilizing a Northern Oriole nest in Kern Co., California (nest held young kingbirds). Robertson (1931) noted the use of eucalyptus trees as kingbird nest sites in southern California. E. Special habitat requirements Grinnell and Miller (1944) conclude that this species re- quires expansive open areas around perch and nest sites. ^ Tyrannus verticalis (con't.) F. Seasonal changes in habitat requirements Grinnell and Swarth (1913) found that Western Kingbirds moved to higher elevations during late summer in the San Jacinto region of California, with numerous 8000 feet sightings. V FOOD A. Food preferences Tyler (1913) notes that these kingbirds usually prey upon grasshoppers, butterflies, bees, and various other insects in California. In the Chihuahuan Desert of New Mexico, Raitt and Pimm (1976) found that grasshoppers were the most important food source. La Rivers (1941) found this species feeding on crickets in Nevada. Knowlton and Harmston (1943) reported that "of 55 stomachs. .. 48 of them contained 110 grasshoppers. .. six stomachs contained eight field crickets" (Utah). Martin et al. (1951) found that bees and wasps, grasshoppers, beetles, bugs, and flies were the most im- portant food items taken in the West. In Joshua Tree National Monument, Miller and Stebbins (1964) found that "Large insects flying in the open are the food resource for this kingbird..." In Texas, Ohlendorf (1974) found that in terms of relative frequency, Coleoptera were the most often captured prey, followed by Hymenoptera, Hemiptera, and Orthoptera. B. Foraging areas Tyler (1913) found these kingbirds hunting (f lycatching) from a wire fence along an alfalfa field in California. Grinnell and Swarth (1913) noted this species feeding in the open meadows surrounding Hemet Lake (southern California) during August. Smith (1966), "T. verticalis was partial to much more open desert shrub and grass areas, and foraged very little along the sides of the canyons." C. Foraging strategies Guillion (1948) noted that a Western Kingbird feeding along the edge of an orchard in Oregon was doing most of its flycatching within four feet of the ground. Although it would drop to the ground for an insect, it remained there for only a moment. La Rivers (1941) noted that this species often flew to the ground from a fence or utility pole to capture an insect. Tyrannus verticalis ( con ' t . ) D. Feeding phenology- Stone (1941) noted Western Kingbirds feeding on elderberries during June in Lake Co., California. Martin et al. (1951) found that elderberries were the only plant food found in appreciable amounts in the stomachs of 139 kingbirds col- lected mainly in California during summer and fall. E. Energy requirements Miller and Stebbins (1964) found that in the deserts of California, Western Kingbirds do not require water, although its presence, as at oasis, probably results in a better food supply. Ohlendorf (1974) showed that although they were not the most frequently captured prey, Orthopterans were the most important food item in terms of expressed as percent of total prey volume (supply most energy to bird). VI REPRODUCTION A. Age at first breeding B. Territorial behavior Dawson (1923) states that kingbirds show the highest levels of territory defense during courtship; hawks, crows, jays and magpies are often driven away from nests. C. Courtship and mating behavior Tyler (1913) noted that these kingbirds often spend several days in "noisy discussion" when choosing a nest site. Smith (1966) gives a detailed account of courtship behavior, including descriptions of vocalizations, tumble flight, wing and tail displays, and various other activities per- formed by both sexes. D. Nesting phenology In California, Dawson (1923) gives laying period as early May to mid-June. California breeding season of 1 May to 25 June given by Wheelock (1904). Willett (1933), "Breeds mostly in May and early June" in California. Tyler (1913) found that it took almost exactly 4 weeks for a pair to complete a nest, lay eggs, and fledge young. California egg dates, as given by Bent (1963), are: 106 records, 17 April to 9 July; 53 records, 10 May to 4 June. E. Length of incubation period Dawson (1923) lists an incubation period of 12-13 days. Wheelock (1904) states that incubation lasts 13 days in California. Bent (1963) gives incubation as lasting 12-14 days. B Tyr annus verticalis (con't.) F. Length of nestling period A 2 week nestling period was given by Dawson (1923). Wheelock (1904) reports that nestlings begin their first flights at 2 weeks of age. G. Growth rates Wheelock (1904), in describing young development, "At first they are fed by regurgitation, but after the third day large insects are torn apart and given fresh." H. Post-breeding behavior Grinnell and Miller (1944) state that "Post-breeding move- ment carries individuals up to 8500 feet" (California). VII POPULATION PARAMETERS A. Clutch size Peterson (1961), "Eggs (3-5; 7) boldly spotted." Bent (1963) gives the average clutch as 3-5 eggs, occasionally up to 6 or 7. » B. Fledging success & C. Mortality rates per age class D. Longevity E. Seasonal abundance In the San Jacinto area of California, Grinnell and Swarth (1913) found that "In late summer they became still more numerous, and more widely spread." Lamb (1912) called this species "Very abundant everywhere during August and September, after which they left to reappear April 2," near Daggett, on the Mojave Desert of California. F. Habitat density figures Balda (1970) found a breeding density of 3 pairs of Western Kingbirds per 100 acres in oak woodland (Arizona). Near Buena Vista Lake, Kern Co., California, Lamb and Howell (1913) found one Western Kingbird nest on about every fourth telegraph pole. Stewart and Kantrud (1972) gave an average range of 2.30 to 4.03 pair of Western Kingbirds per square in North Dakota, with a maximum density of 24 pairs/square mile. In a cottonwood-willow habitat of California, Ingles (1950) discovered 7 pair of nesting kingbirds on a 33 acre \ 4 Tyrannus verticalis (con't.) study area. In Montana, Walcheck (1970) found 3 pairs per 100 acres in a pine- juniper woodland, and 13 pairs per 100 acres in a cottonwood forest; kingbirds were absent in sagebrush habitat. In riparian habitat in the Sacramento Valley, California, Gaines (1974) found 26 to 38 territorial male Western Kingbirds per square km. VIII INTERSPECIFIC INTERACTIONS A. Predation Hamilton (1941) found the remains of Western Kingbirds at Burrowing Owl nests near Denver, Colorado. Bent (1963) feels that "These kingbirds and their eggs and young are doubtless preyed upon by the ordinary mammalian and avian predators. . .but they are valiant and often successful in driving their enemies away." B. Competition Dawson (1923) states that Western and Cassin Kingbirds often nest close to one another without adverse interactions. Swarth (1904) has noted these two kingbirds migrating together in Arizona. However, DeBenedictis and McCaskie (1967) found that intense fighting may occur between Western and Cassin' s Kingbirds, especially near the nest site--"these two species may be as interspecif ically territorial as they are intraspecif ically territorial." In Arizona, Gil- man (1915) found a Bendire Thrasher trying to drive a pair of Western Kingbirds from their nest: the kingbirds kept the site. In Texas, Ohlendorf (1974) showed that between Western and Cassin' s Kingbirds, "There was no apparent interspecific defense of feeding areas, although the nest sites were defended." Hespenheide (1964) discusses several factors that prevent serious interspecific competititon in kingbirds. C. Parasitism Friedmann (1963) notes the infrequent parasitism of Western Kingbird nests by cowbirds. Friedmann et al. (1977) state that although this kingbird has raised cowbird young, it usually "rejects" the eggs. Smith (1972) followed a king- bird pair that fledged one cowbird and one kingbird in Nebraska. IX STATUS A. Past population trends Grinnell and Miller (1944) called this species locally com- /fr * mon to abundant in interior valleys of California. Hollister v^, (1908) found this species "abundant along the Colorado River" near Needles, California. Tyrannus verticalis (con't.) B. Present population status Small (1974) describes this species as common in California during summer. Davis and Webster (1970) state that Western Kingbirds have been expanding their breeding range eastward (Texas). Smith (1966) felt that "its recent range expansion has probably been much influenced by the plantings settlers made on the plains." C. Population limiting factors Grinnell and Miller (1944) found that "Woodland must be of far-scattered trees to harbor this kingbird." D. Environmental quality: adverse impacts E. Potential for endangered status Tyrannus verticalis (con't.) XI LITERATURE CITED 10 American Ornithologists' Union. 1957. Checklist of North American birds. 5th edition. American Ornithologists' Union, Baltimore, Maryland. 691 pp. Balda, R. P. 1970. Effects of spring leaf-fall on composi- tion and density of breeding birds in two southern Arizona woodlands. Condor 72:325-331. Bent, A. C. 1942. Life histories of North American flycatchers, larks, swallows, and their allies. U. S. Nat. Mus. Bull. 179:1-555. Carter, F. 1937. Bird life at Twentynine Palms. Condor 39:210-219. Davis, L. I., and F. S. Webster, Jr. 1970. An intergeneric hybrid flycatcher (Tyrannus x Muscivora) . Condor 72:37-42. Dawson, W. L. 1923. The birds of California. Vol. 2. South Moulton Co., San Francisco. DeBenedictis, P. and R. G. McCaskie. 1967. Cassin's Kingbird and plumbeous Solitary Vireo in the White Mountains of California. Condor 69:424-425. Friedmann, H. 1963. Host relations of the parasitic cowbirds. U.S. Nat. Mus. Bull. 233:1-276. Friedmann, H. , L. F. Kiff and S. I. Rothstein. 1977. A further contribution to knowledge of the host relations of the parasitic cowbirds. Smithsonian Contrib. Zool. No. 235. 75 pp. Gaines, D. 1974. A new look at the nesting riparian avifauna of the Sacramento Valley, California. Western Birds 5: 61-80. Gilman, M. F. 1915. A forty acre bird census at Sacaton, Arizona. Condor 17:86-90. Grinnell, J. 1914. An account of the mammals and birds of the lower Colorado Valley. Univ. California Publ. Zool. 12:51-294. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna No. 27. 008 pp. Grinnell, J. and H. S. Swarth. 1913. An account of the birds and mammals of the San Jacinto area of southern California. Univ. California Publ. Zool. 10:197-406. 11 Tyr annus verticalis (con't.) Gullion, G. W. 1948. An early record of the Western Kingbird in Lane County, Oregon. Condor 50:46. Hamilton, W. J., Jr. 1941. A note on the food of the western Burrowing Owl. Condor 43:74. Hellmayr, C. E. 1927. Catalogue of birds of the Americas and the adjacent islands. Part 5. Field Mus. Nat. Hist. Zool. Ser. Publ. 242, Vol. 13. Hespenheide, H. 1964. Competition and the Genus Tyrannus . Wilson Bull. 76:265-281. Hollister, N. 1908. Birds of the region about Needles, Calif- ornia. Auk 25:455-462. Hunter, J. S. 1905. Double nest of Arkansas Kingbird. Condor 7:53. Ingles, L. G. 1950. Nesting birds of the willow-cottonwood community in California. Auk 67:325-332. Johnson, D. H. , M. D. Bryant and A. H. Miller. 1948. Verte- brate animals of the Providence Mountains area of California. Univ. California Publ. Zool. 48:221-376. Kennedy, C. H. 1914. The effects of irrigation on bird life in the Yakima Valley, Washington. Condor 16:250-255. Knowlton, G. F. and F. C. Harms ton. 1943. Grasshoppers and crickets eaten by Utah birds. Auk 60:589-591. Lamb, C. 1912. Birds of a Mohave Desert oasis. Condor 14: 32-40. Lamb, C. and A. B. Howell. 1913. Notes from Buena Vista Lake and Fort Tejon. Condor 15:115-120. LaRivers, I. 1941. The Mormon cricket as food for birds. Condor 43:65-69. Martin, A. C. , H. S. Zim and A. L. Nelson. 1951. American wildlife and plants. McGraw Hill Book Co., Inc., N.Y. Miller, A. H. and R. C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. California Press, Berkeley. 452 pp. Ohlendorf, H. M. 1974. Competitive relationships among king- birds (Tyrannus) in Trans-Pecos Texas. Wilson Bull. 86: 357-373. 12 Tyrannus verticalis (con't.) Peterson, R. T. 1961. A field guide to western birds. Houghton Mifflin Co.. Boston. 366 pp. Phillips, A., J. Marshall and G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. 212 pp. Pierce, W. M. and E. L. Sumner, Jr. 1927. New records from Big Bear Lake, San Bernardino Mountains, California. Condor 29:82. Pinckney, A. J. 1938. A hand-reared Arkansas Kingbird. Wilson Bull. 50:290-291. Quigley, R. , Jr. 1944. Unusual nest site of the Western King- bird. Condor 46:206 Raitt, R. J. and S. L. Pimm. 1976. Dynamics of bird communi- ties in the Chihuahuan Desert, New Mexico. Condor 78:427- 442. Ridgway, R. 1907. The birds of North and Middle America. Part 4. Bull. U.S. Nat. Mus. No. 50. Robertson, J. McB. 1931. Birds and eucalyptus trees. Condor 33:137-139. Small, A. 1974. The birds of California. Winchester Press, New York. 310 pp. Smith, T. S. 1972. Cowbird parasitism of Western Kingbird and Baltimore Oriole nests. Wilson Bull. 84:497. Smith, W. J. 1966. Communication and relationships in the Genus Tyrannus . Publ. Nuttall. Ornithol. Club No. 6, 250 pp. Stevens, F. 1903. Bird notes from eastern California and Western Arizona. Condor 5:75-78; 100-105. Stewart, R. E. and H. A. Kantrud. 1972. Population estimates of breeding birds in North Dakota. Auk 89:766-788. Stone, N. W. 1941. Elderberries as food for birds. Condor 43:121. Swarth, H. S. 1904. Birds of the Huachuca Mountains, Arizona. Pacific Coast Avifauna No. 4. 70 pp. Tyler J. G. 1913. Some birds of the Fresno District, Calif- ornia. Pacific Coast Avifauna No. 9. 114 pp. Walcheck, K. C. 1970. Nesting bird ecology of four plant communities in the Missouri River Breaks, Montana. Wilson Bull. 82:370-382. (J 13 W Tyr annus verticalis (con't.) Wauer, R. H. 1962. A survey of the birds of Death Valley. Condor 64:220-233. Wauer, R. H. 1964. Ecological distribution of the birds of the Panamint Mountains, California. Condor 66:287-301. Whedon, A. D. 1938. Nesting behavior of Kingbirds. Wilson Bull. 50:288-290. Wheelock, I. G. 1904. Birds of California. A. C. McClurg and Co., Chicago. 578 pp. Willett, G. 1933. A revised list of the birds of southwestern California. Pacific Coast Avifauna No. 21. 204 pp. Willett, G. 1951. Birds of the southern California deserts. Los Angeles County Mus. Zool. Publ. No. 6. 39 pp. » fr u WESTERN MEADOWLARK m Sturnella neglecta I TAXONOMY A. Type description AOU (1957) Sturnella neglecta confluenta Rathbun, Auk, 36, no. 1, Jan. 1917, p. 68. (Seattle, Washington.) Sturnella neglecta neglecta: Sturnella neglecta Audubon, Birds Amer. (octavo ea.), vol" T, 1884, p. 339, pi. 489. (Missouri River about Fort Crogan = Old Fort Union, North Dakota. ) B. Current systematic treatments AOU (1957) places Sturnella neglecta in the Order Passeri- formes. Family Icteridae with two subspecies. Mayr and Short (1970) note that S. neglecta and S. magna hybridize in their zone of overlap and should be "Further studied to determine their relationship. They are considered sibling species. Oberholser (1974) considers S. neglecta, S_. ludoviciana, as does Kincaid (1974). This is based on a name assigned by Brisson, prior to Audubon describing the species. C. Synonomies of scientific nomenclature Grinnell and Miller (1944), Sturnella hippocrepus, Sturnella magna neglecta, Sturnella magna. Oberholser (19 74), S. luctoviciana. Kincaid (1974), S. ludoviciana. D. Synonomies of vernacular nomenclature Grinnell and Miller (1944), Western Meadowlark, Meadow Lark, Missouri Meadowlark, Western Lark. II DESCRIPTION A. External morphology of adults Dawson (1923): "Adult male. General color of underparts black-brown, modified by much tawny and buffy-gray edgings of feathers, which throw the black into stripes and bars with a suggestion of herring-bone pattern; the tawny heaviest on secondaries and upper-tail feathers, where taking the form of partial bands; a median crown stripe and posterior por- tion of superciliary sordid white or buffy; anterior portion of superciliary, lower cheeks, chin, upper throat, breast, middle belly, and edge of wing, rich yellow; a large black crescent on upper breast; sides and flanks black- streaked, i » Stumella neglecta (con't.) and spotted with pale brown on a buffy whitish ground. Bill variegated, tawny black and white. Female, Like male but smaller and paler, with some substitutions of brown for black in streaking; black of jugulum veiled by grayish tips of feathers; yellow of breast, etc., duller." Baird et al . (1905): "Feathers above, dark brown, margined with brownish- white, with a terminal blotch of pale reddish- brown. Exposed portion on wings and tail with transverse band, which in the latter are completely isolated from each other, narrow and linear. Beneath yellow, with a black pectoral crescent. The yellow of the throat extending on the sides of the maxilla. Sides, crissum, and tibiae very pale reddish-brown, or nearly white, streaked with blackish. Head with a light median and superciliary stripe, the latter yellow in front of the eye; a blackish line behind it. The transverse lines on the feathers above with a tendency to become confluent near the exterior margin. B. External morphology of subadult age classes Dawson (1923): "Immature birds resemble parents but are grayer with pale yellow more confined and they lack the jugular crescent. Bent (1958) says the young are practically indistinguishable from the adults once they get their first winter plumage. C. Distinguishing characteristics Interspecific - Baird et al. (1905) describes the differences between ;S. neglecta and S^. magna the eastern species. Dawson (1923) describes the eastern species as lacking the yellow on lower cheek. Robbins et al . (1966) say the western species can be told from the eastern by its paler back and tail. Kincaid (1974): "Similar to Lilian's Eastern Meadowlark, S. magna lilianae, but wing and tail longer, sides of head more whitish, yellow of lower surface lighter," in reference to S. neglecta. Bent (1958): "These two species Ceastern and western] can be easily recognized by their white lateral tail feathers, yellow breast, and black crescent," but it is very difficult to tell them apart. Intraspecific - Bent (1958) describes conf luenta as similar to neglecta but the bars on the tail and tertials are broader and much more confluent; upper parts are darker throughout and the black areas more extensive; yellow of underparts darker. Kincaid (1974), S. n. conf luenta: "Resembling _S. n. neglecta but upper parts more deeply colored with black markings broader; bars on tertials and tail wider; yellow of lower parts a little darker." f> e Sturnella neglecta (con't.) ^ GEOGRAPHICAL DISTRIBUTION A. Overall distribution of the species AOU (1957) Sturnella neglecta in general: "Central British Columbia, central Alberta, central Saskatchewan, southern Manitoba, western and southern Ontario, northern Michigan, and northwestern Ohio south to Baja California, Zacatecas, Nuevo Leon, central Texas and Louisiana." Sturnella neglecta conf luenta: "Breeds from southwestern and central British Columbia south through Washington, western Idaho, and Oregon to southern California, intergrading with S. n. neglecta in central Idaho, Death Valley, and San Diego County, California." Sturnella neglecta neglecta: "Breeds from southern British Columbia, central Alberta, central Saskatchewan, southern Manitoba, western Ontario, northeastern Minnesota, northern Wisconsin, northern Michigan, southern Ontario, northwestern Ohio south through western Montana, eastern Idaho, Nevada, southeastern California to northwestern Baja California, northwestern Sonora, central and southeastern Arizona, eastern Sonora, Sinaloa, Jalisco, northwestern Durango, Guanajuato, southeastern Coahuila, central Texas, northwestern Louisiana, northwestern Arkansas, central and eastern Missouri, south- western Tennessee, southern Illinois, southern Michigan, and central Ohio." Gullion et al . (1959): "Noted as a common resident in the valleys and sagebrush areas... but also found to be common throughout the year on desert areas, particularly in desert grassland and creosote-bush." Lanyon (1956) describes the sympatric distribution of Meadowlarks in the north-central states. B. California distribution of the species Grinnell and Miller (1944): "Occurs throughout the state with exception of most arid and barren tracts of deserts, roughest mountains and densest forests. Included are all coastal islands, and many high points in the Sierra Nevada reached by vagrants. Life-zones occupied in breeding season; Lower and Upper Sonoran, and Transition." Dawson (1923): "Resident and general distribution throughout state, save arid portions of the desert, broken mountain sections, and the dense forests. Breeds from Lower Sonoran to Lower Boreal." Small (1974) calls S. neglecta a common resident. in the state. Sturnella neglecta (con't.) C. California desert distribution Grinnell and Miller (1944) say that breeding populations are rare in the desert but that on southeastern deserts numbers have increased with the development of oases and irrigated lands. They give records for San Bernardino Mountains, San Jacinto Mountains, Owens Valley, Inyo Moun- tains, Panamint and Death Valleys, San Bernardino County, Riverside County and Imperial County. Dawson (1923) lists Colorado deserts at Indio and Inyo County as breeding sites. Willett (1951) calls S. neglecta a scattered resident in the southern desert. PhiTlips et al . (1964): "In occasional years heavy winter or spring rains on the desert will bring up a stand of grass which will become inhabited with Western Meadowlarks. " D. Seasonal variations in distribution AOU (1957), S. n. confluenta: "Winters from Vancouver Island and the adjacent mainland southward. Migrant, in part, in the northeastern section of its range." _S. n. neglecta: "Winters north to southern Alberta, southern Saskatchewan , southern Manitoba, and southern Wisconsin; south to southern Baja California, Michoacan Mexico, Tamaulipas, southern Texas, Louisiana, and Mississippi. Casual in Alaskan northern British Columbia, Mackenzie, northern Alberta and Kentucky. IV HABITAT A. Biotopic affinities Grinnell and Miller (1944): "Life-zones occupied in breed- ing; Lower Sonoran, Upper Sonoran, Transition." Habitat in grassy plains, hillslopes and meadowlands, may be mod- erately intermixed with bushes. Peterson (1961): "Open fields, meadows, grassy plains, prairies." Kincaid (1974): "...in habits prairies, meadows, and fields. Habit details frequently differ however." Walcheck (1970) in a study in the Missouri River Breaks, Montana, found S. neglecta associated with greasewood- sagebrush shrubTand, sagebrush grassland, and pine- juniper woodland. Lanyon (1957) notes that neglecta selects drier environments than _S. magna. B. Altitudinal range Grinnell and Miller (1944) - 200 feet to 11,000 feet. Dawson (1923) - up to 11,000 feet. Bent (1958) - about 8,000 feet is the highest in California. <* # Sturnella neglecta (con't.) • » C. Home range size Bent (1958) - 10 to 32 acres. Lanyon (1957) - 3 to 15 acres. These areas were found to undergo changes in shape through the season. Kendeigh (1941) in 50 acres of priarie noted 6 S. neglecta nesting and feeding in the area. D. Territory requirements Perch sites - Bent (1958) says the males have singing perches on trees or posts in their territory. Courtship and mating sites Nest sites - Baird et al. (1905) state that they build their nest in a slight depression under a bunch of grass, and concealed by it. Dawson (1923): "On ground, chiefly in meadows or pastures, in thick grass or weeds. Peterson (1961): "A grassy saucer, partially domed, among grass." Bent (1958) describes a nest placed in a growth of low grass that was arched over with strips of dry bark. Roseberry and Klimstra (1970) in a study of S. magna note pastures to be the favored nest site and then Hayfields. E. Special habitat requirements F. Seasonal changes in habitat requirements Kincaid (1974): "During spring and summer the western nests on uplands where grass is comparatively short and dry; in winter habitat preferences are less marked... the western is more likely to forage on bare, desert-like ground. V FOOD A. Food preferences Baird et al . (1905) say they feed chiefly on insects, seeds and grain. Bent (1958; says the diet consists of grass- hoppers, beetles, crickets; 70% animal matter to 30% vege- table. Kincaid (1974): "The vegetable portions of its diet consists of grain (corn, oats, wheat, barley), a little fruit pulp, and weed seeds." Bryant (1914) found meadowlarks to eat 63.3% animal food and 36.77D vegetable food; grain was the largest by volume. B. Foraging areas Grinnell and Miller (1944) give foraging areas as matted grass tangles, living vegetation, in cultivated lands. $ Stumella neglecta (con't.) C. Foraging strategies Grinnell and Miller (1944) say that much food is obtained from the ground surface by turning over clods and by drill- ing the soil. D. Feeding phenology Bryant (1914) found vegetable food to make up the largest part of the diet in January through March and October through December. Animal food made up the largest percent in April through September. E. Energy requirements Dawson (1923) gives an estimate of 6 pounds of food needed annually by an adult. VI REPRODUCTION A. Age at first breeding B. Territorial behavior Bent (1958) prints an exerpt from a study by Kendeigh (1941): "Territorial behavior is well established in this species, although only the male defends the territory." They have singing posts in the territory where they perch while singing. Lanyon (1957): "Territories were established and maintained solely by the males and defended for a period of up to 4 weeks before the arrival of the female. Maintenance of territories continued until fledging of the final brood." Species of a different genus were often tolerated in the territory. C. Courtship and mating behavior Bent (1958): "It probably consists of song and plumages display." Lanyon (1957) says that both male and female sing. Lanyon (1957) found males that did not obtain a mate could not maintain territories. Pair formation took place immediately upon arrival of the female on the male's territory. 53% of male S. neglecta had more than one mate. D. Nesting phenology Bent (1958) records egg dates from California from February 11 to June 10. Kincaid (1974) reports the nesting season in Texas as mid-March to mid-August. Lanyon (1957) gives 18 April as the average date of egg-laying initiation; last egg laid - 4 May. e Sturnella neglecta (con't.) E. Length of incubation period Bent (1958) - 13 days. Lanyon (1957) - 13 to 14 days, occasionally 15 days. F. Length of nestling period Bent (1958) - about 4 weeks. G. Growth rates Bent (1958) gives a detailed description of each days growth for the eastern species. By the eleventh or twelfth day the young leave the nest at which time they can fly a little if necessary. H. Post-breeding behavior Bent (1958) says the male chases his young out of his terri- tory at about 1 month of age. "After the last brood of young are... on the wing, old and young gather into groups... and begin their late summer wanderings..." Lanyon (1957) says that they become gregarious following the late- summer molt. POPULATION PARAMETERS A. Clutch size Dawson (1923) - 4 to 5, rarely 6 or 7. Peterson (1961) - 3 to 7. Bent (1958) - 3 to 7, 5 being the commonest. B. Fledging success Lanyon (1957) records 50% of nests fledging young. C. Mortality rates per age class D. Longevity Kennard (1975) did not publish an age record from band returns for the Western Meadowlark, but the oldest eastern one he found was 8 years 8 months. E. Seasonal abundance Bent (1958): "...many birds winter on suitable portions of the Colorado and Mohave deserts where this species is unknown in the summer." F. Habitat density figures Sturnella neglecta (con't.) II INTERSPECIFIC INTERACTIONS A. Predation Bent (1958): "Meadowlarks have many enemies, more especially Golden Eagles, Prairie Falcons, Marsh Hawks, Red-tailed Hawks," and also skunks, weasels, minks, raccoons, coyotes, snakes and crows. "Some nests are probably trodden by cattle or sheep. Roseberry and Klimstra (1970) attribute losses to predation at 51% of total losses. B. Competition Kendeigh (1941) on a 50-acre priarie noted 16 species of passerines using the area for feeding and/or nesting. C. Parasitism Friedmann et al . (1977) do not list the Western Meadowlark as being a cowbird victim. The eastern species is, however. IX STATUS A. Past population trends Baird et al . (1905) report the species to be abundant in California. Lanyon (1957) notes a marked northeastward v~r extension of the range of neglecta during the past 50 years. * B. Present population status Lanyon (1957) notes the increasing range of both the eastern and western species as a result of increased suitable habi- tat due to greatly expanded agricultural activities. Bryant (1914) gives a long discussion on the economic status of the western meadowlark in California. This study was prompted by the number of complaints against the meadowlark by farmers who said they ate sprouting grain. The results of Bryant's study (1914) indicate that the meadowlark actually does more good than harm by eating cutworms and grasshoppers. C. Population limiting factors D. Environmental quality: adverse impacts E. Potential for endangered status