0 f Vol. 14, No. 1, 1983 WESTERN BIRDS Quarterly Journal of Western Field Ornithologists President: Terence R. Wahl Vice-President: Laurence C. Binford Treasurer/ Membership Secretary: Garth Alton Circulation Manager: Elizabeth Copper Recording Secretary: Jean-Marie Spoelman Directors: Laurence C. Binford, Jeanne A. Conry, Peter Gent, John S. Luther, Guy McCaskie, Richard W. Stallcup, Terence R. Wahl, Timothy Manolis, Janet Witzeman Editor: Alan M. Craig Associate Editors: Cameron Barrows, Narca A. Moore-Craig Editorial Board: Robert Andrews, Alan Baldridge, William H. Behle, Andrew J. Berger, Laurence C. Binford (Chairman), Jeanne A. Conry, David F. DeSante, Richard Erickson, Joseph Greenberg, Joseph R. Jehl, Jr., Ned K. Johnson, Virginia P. Johnson, Brina Kessel, Charles S. Lawson, Stephen A. Laymon, John S. Luther, Tim Manolis, Brian J. McCaffery, Guy McCaskie, M. Timothy Myres, Harry B. Nehls, Thomas L, Rodgers, Stephen M. Russell, Oliver K. Scott, P. David Skaar, Richard W. Stallcup, David Stirling, G. Shumway Suffel, Charles Trost, Terence R. Wahl, Roland H. Wauer, Bruce Webb, Dale A. Zimmerman Layout artist: Virginia P. Johnson Membership dues, for individuals and institutions, including subscription to Western Birds: Patron, $1000; Life, $150; Supporting, $30 annually: Contributing, $20 annually; Regular $14 U.S. ($17 outside U.S.), annually. Dues and contributions are tax-deductible to the extent allowed by law. Send membership dues, changes of address, and correspondence regarding missing issues to Garth Alton, 17 Camino Lenada, Orinda, CA 94563. Make checks payable to Western Field Ornithologists. Send orders for back issues and special publications to Elizabeth Copper, P.O. Box 595, Coronado, CA 92118. Back issues of California Birds/Western Birds: $15 per volume, $4.00 for single issues. Xerox copies of out of print issues (Vol. 1, No. 1; Vol. 2, Nos. 1 and 4; Vol. 6, No. 2): $4.50 each. Checklist of the Birds of California: $2.00 each, 10 or more $1.50 each. Pelagic Birds of Monterey Bay, California: $2.50 each, 10 or more $2.00 each, 40 or more $1.50 each. All postpaid. Send rare bird reports for Arizona to Robert A. Witzeman, 4619 E. Arcadia Lane, Phoenix, AZ 85018; for California, to B.D. Parmeter, 2500 Emerson Street, Napa, CA 94558; for Colorado, to CFO Records Committee, Denver Museum of Natural History, City Park, Denver, CO 80205; for Oregon, to Oregon Bird Records Commit- tee, P.O. Box 10373, Eugene, OR 97440; and for Vancouver, British Columbia, to Wayne C. Weber, 303-9153 Saturna Drive, Burnaby, B.C. V3J 7K1. Published — August 30, 1983. WESTERN BIRDS ADVERTISING RATES AND SPECIFICATIONS Full Page 4 x 6^/4 inches $60 per issue $200 per year Half Page 4 x 3% inches $40 per issue $130 per year Quarter Page 4 x l"/i6 inches $30 per issue $110 per year Offset printing, one column per page, 4 inches wide. Glossy, black and white photos are acceptable; half-tone screen size: 133 line. Photo-ready copy is requested. If this is not possible, extra charges for typesetting will be made as follows: $15 full page, $10 half page, $5 quarter page. Send copy with remittance to Garth Alton, 17 Camino Lenada, Orinda, CA 94563. Make checks payable to Western Field Ornithologists. A 15% commission is allowed for agencies. WESTERN BIRDS Volume 14, Number 1, 1983 FIFTH REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE JOHN S. LUTHER, College of Alameda, 555 Atlantic Avenue, Alameda, California 94501 GUY McCASKIE, 954 Grove Street, Imperial Beach, California 92032 JON DUNN, 17437 Rancho Street, Encino, California 91316 This report contains recent decisions of the California Bird Records Com- mittee (CBRC). It officially adds the following species to the state list of California: Greater Shearwater {Puffinus gravis), Cook’s Petrel (Pterodroma cookii), Stejneger’s Petrel (Pterodroma longirostris) , Band-rumped (Har- court’s) Storm-Petrel (Oceanodroma castro), Red-tailed Tropicbird (Phaethon rubricauda), Mongolian Plover (Charadrius mongolus), Sand- wich Tern (Sterna sanduicensis) , Crested Auklet (Aethia cristatella) , Yellow- bellied Flycatcher (Empidonax flauiuentris) , Sedge (Short-billed Marsh) Wren (Cistothorus platensis) , Dusky Warbler (Phylloscopus fuscatus) , and White- winged Crossbill (Loxia leucoptera) . These bring the state list to 539 species. Jones et al. (West. Birds 12:57-82, 1981) updated the state list; this Records Committee report was prepared earlier and differs from their list in a few in- stances. The committee consists of Laurence C. Binford (Vice-Secretary), Jon Dunn, Richard Erickson, Kimball Garrett, Lee Jones, Paul Lehman, Guy McCaskie, Joseph Morlan, Benjamin D. Parmeter (Secretary) and Richard Webster. David DeSante, Arnold Small, Richard Stallcup, Phil Unitt and John Luther also worked on the records reported in this paper. The present committee and former members acknowledge the cooperation and support from those observers who have taken the time and effort to submit their records. Without them the committee could not function. Please continue to support your committee in your documentation of rare birds as they occur in California. Western Birds 14; 1-16, 1983 1 CALIFORNIA BIRD RECORDS The comments following each species are those of the authors and not of the CBRC. The file number assigned to each species is given in parentheses. All records are on file with the Secretary and are available for examination by interested persons. All records are sight records unless otherwise noted. The initials of those persons who submitted documentation for a record follow each accepted record. If the person or persons finding a bird submitted a report, their initials are given first and are separated from those of other observers by a semicolon. ACCEPTED RECORDS YELLOW-BILLED LOON (Gauia adamsii). One immature (87-1978) 12 Feb 1978, Monterey Bay, Monterey Co. (VR). This species occurs annually along the coast of California (Remsen and Binford, West. Birds 6:7-20, 1975). GREATER SHEARWATER (Puffinus gravis). One (17-1979) 24 Feb 1979, Monterey Bay, Monterey Co. (JD, KG: FF, SSa, BSh). This is not only the first of this species to be identified off the coast of California but also the first in the North Pacific. This species breeds on islands in the south Atlantic and ranges over most of the Atlantic including the waters off Tierra del Fuego. An in- dividual straying into the Pacific around Tierra del Fuego could then occur anywhere in that large ocean. SHORT-TAILED SHEARWATER (Puffinus tenuirostris) . Two (44-1978) 15 Jan 1977, Cordelle Banks, Marin Co. (GMcC). Eighteen (69-1978) 5 Feb 1978, Monterey Bay, Monterey Co. (JM,DR). One (86-1978) 20 Mar 1978, Monterey Bay, Monterey Co. (DR). This species has proven to be of regular occurrence in mid-winter off the coast of California and is no longer reviewed by the CBRC. COOK’S PETREL (Pterodroma cookii). One (122-1980) 3 Oct 1979, 36 miles west northwest of Point Arena, Mendocino Co. (GF). Two (71-1979) 17 Nov 1979 be- tween 40 and 60 miles offshore from Cambria, San Luis Obispo Co. (GMcC, JD, RAE, DR, RS); photo on file. These sightings are the first for California waters. This species breeds on islands around New Zealand and wanders over much of the Pacific during the non-breeding season, having been recorded off Baja California (Loomis, Proc. Calif. Acad. Sci. , 4th ser., vol. 2, pt. 2:1-187, 1918) and the extreme north Pacific (Wahl, West. Birds 9:45-66, 1978). The very closely related P. defilipiana, considered by many authorities to be a subspecies of P. cookii, is probably indistinguishable in the field from P. cookii and is not excluded here. P. defilipiana breeds on the Juan Fernandez Islands off Chile, but has not been collected north of Central Peru. STEJNEGER’S PETREL (Pterodroma longirostris) . One (72-1979) 17 Nov 1979 about 50 miles offshore from Cambria, San Luis Obispo Co. (GMcC, JD, RAE, DR, RS). This is the first record for California. This species was collected in Nov 1906 about 600 miles west of San Francisco (Loomis, Proc. Calif. Acad. Sci., 4th ser., vol. 2, pt. 2:1-187, 1918). 2 CALIFORNIA BIRD RECORDS WILSON’S STORM-PETREL (Oceanites oceanicus). At least one (possibly three) (124-1978) 30 Sep 1978, Monterey Bay, Monterey Co. (JM). This species is now recorded in Monterey Bay each year during the Sep-Oct period, but remains virtually unknown elsewhere in the North Pacific. GALAPAGOS STORM-PETREL (Oceanodroma fethys). One (57-1976) 18 Aug 1976, 20 miles south of Anacapa Island, Los Angeles Co. (VR; VE, LH, IMacG, JMcD, SS). One specimen from Carmel, Monterey Co., 21 Jan 1969 (Yadon, Auk 87:588-589, 1970) and one seen on Monterey Bay between 24 Sep and 9 Oct 1977 (Am. Birds 32:251, 1978) are the only ones previously recorded in California waters. The Carmel bird was of the small southern race kelsalli which nests on islands along the coast of Peru. BAND-RUMPED STORM-PETREL (Oceanodroma castro). One (103-1973) 12 Sep 1970, about 25 miles west of San Diego, San Diego Co. (GMcC; JA, SS, RW). This is the first to be recorded from California. The nearest known nesting localities are in the Hawaiian and Galapagos islands, but this species clearly wanders widely over the warmer ocean waters. RED-TAILED TROPICBIRD (Phaethon rubricauda). One (32-1979) 3 Jul 1979, S. E. Farallon Island, San Francisco Co. (PMG, LS). This is the first to be recorded in California. This is the common tropicbird over much of the Pacific, regularly wandering into the eastern Pacific, with a specimen taken about 250 miles WSW (31°39'N, 123°22'W) of San Diego on 13 Feb 1967 (Gould et al., Smithsonian Contr. Zool. 158: 206-231, 1974). BROWN BOOBY (Sula leucogaster) . One subadult (50-1978) 19 Aug-30 Nov 1977, Lake Havasu, San Bernardino Co. (GMcC). This is a casual late summer wanderer to the southwestern United States (Mc- Caskie, Calif, Birds 1:117-142, 1970). REDDISH EGRET (Egretta rufescens). One adult (45-1978) 24 Apr- 14 May 1977. Imperial Beach, San Diego Co. (GMcC). One (115-1977) 22 May 1977, Point Mugu marshes, Ventura Co. (LJ). One immature (57-1978) 8-17 Oct 1977, San Diego River Flood Control Channel, San Diego Co. (GMcC). Three immatures (57-1978) 150ct-13Nov 1977 (with one or two remaining through the winter, and one still pres- ent on 30 Jun 1978), near Imperial Beach, San Diego Co. (GMcC). This species is of annual occurrence along the coast of southern California south of Los Angeles, with most found in the San Diego area, and is no longer reviewed by the CBRC. YELLOW-CROWNED NIGHT-HERON (Nifctanassa uiolacea). One adult (46-1978) 11 May 1977, Irvine, Orange Co. (DH; GMcC); photo on file. This is only the seventh to be recorded in California. WHITE IBIS (Eudocimus albus) One adult (49-1978) 25 June- 14 Jul 1977, south end Salton Sea, Imperial Co. (GMcC). There are only three previous records for California: one (specimen) in San Diego 20 Nov 1935, another in Marin Co. 14 May-9 Sep 1977 (not yet reviewed by the CBRC), and the third on the Salton Sea 10 Jul-5 Aug 1976. 3 CALIFORNIA BIRD RECORDS TRUMPETER SWAN {Ci>ngus buccinator) . One adult (16-1979) 24 Feb 1979, Tule Lake, Lake Co. (SL, KVV). There are only about 15 records of this species for California since 1900 (Roberson, Rare birds of the West Coast, 1980) . EMPEROR GOOSE (Chen canagica). One adult (85-1978) 1 Jan-20 Mar 1978, Moss Landing, Monterey Co. (DR). One immature (75-1979) 28 Oct 1978, Lower Klamath National Wildlife Refuge, Siskiyou Co. (BD). This is an annual visitor to California and is no longer reviewed by the CBRC. GARGANEY (Anas querquedula) . One male (19-1979) 21 Mar-4 Apr 1979, Lake Elsinore, Riverside Co. (RP; JD, RAE, GMcC, DR). This is only the second to be found in California. However, a specimen taken near Mt. Vernon, Washington, during Mar 1961 (Larry Spear pers. comm.) and two others seen at Iona Island in British Columbia 14-28 May 1977 and 8-12 Jun 1979 (Rober- son, Rare birds of the West Coast, 1980) , along with the previous record for California (Luther et al., West. Birds 10:169-187, 1979), suggest that the species may be more regular than thought along the West Coast in spring. TUFTED DUCK (Aythya fuligula). One immature male (78-1978) 12 Jan- 11 Feb 1978, Limantour area, Marin Co. (JM, VR). One adult male (63-1978) 30 Jan-5 Feb 1978, Lake Hennessey, Napa Co. (JP; JM). One adult male (13-1979) 2 Dec 1978-13 Jan 1979, Oakland, Alameda Co. (JM). One immature male (12-1979) 29 Dec 1978-25 Feb 1979, Limantour area, Marin Co. (JM) This species is now being recorded along the coast of California each winter. These records, along with records from Oregon, Washington and British Columbia, indicate small numbers are regularly wintering along the west coast of North America. AMERICAN OYSTERCATCHER (Haematopus palliatus). One (97-1978) 20-21 Apr 1978, Pt. Loma, San Diego Co. (RAE, PU). One (9-1979) 22 Dec 1978-14 Jan 1979, Pt. Fermin, Los Angeles Co. (DHo, JD, KG, GMcC). These are only the second and third records from the mainland coast of California in over 100 years; the first during that period was of one (photographed) on the coast of San Luis Obispo Co. 25 Oct 1964-20 Feb 1965 (Aud. Field Notes 19:416, 1965). There is an inland record of three birds at the Salton Sea and apparently there are resi- dent birds on the Channel Islands. MONGOLIAN PLOVER (Charadrius mongolus). One juvenile (176-1980) 13-19 Sep 1980, Moss Landing, Monterey Co. (DD; GMcC, RAE, RS, BU); photo on file. This is the first to be recorded in California. However, this Asiatic breeder regularly strays into western Alaska and has occurred twice in fall along the Oregon coast (Roberson, Rare birds of the West Coast, 1980). WILSON’S PLOVER (Charadrius wilsonia). One (58-1979) 21 Apr-24 Jun 1979, Pt. Mugu, Ventura Co. (RW; JD, KG, DR). This is only the third to occur in California in over 50 years. The others were a nesting pair at the Salton Sea 20 May 1948 and one at McGrath State Beach 27-29 Jun 1977 (Am. Birds 31: 1189, 1977). UPLAND SANDPIPER (Bartramia longicauda). One (71-1976) 13 Sep 1976, Lake Talawa, Del Norte Co. (BM). One (59-1979) 28 May 1979, Deep Springs, Inyo Co. (RW; PL). There are only about 10 records of this species in California equally split between spring and fall. 4 CALIFORNIA BIRD RECORDS SHARP-TAILED SANDPIPER (Calidris acuminata). One (73-1976) 6-9 Oct 1976, Areata Bottoms, Humboldt Co. (DRu). One (121-1978) 14-30 Oct 1978, Carmel River, Monterey Co. (RS; FB, JM, DR); photo on file. One (10-1979) 13 Nov 1978, Bolinas, Marin Co. (SGe; LSt) . One (76-1979) 27 Oct 1979, Moss Landing, Monterey Co. (RS). One (77-1979) 31 Oct 1979, Pt. Reyes, Marin Co. (RS). This species occurs along the California coast in small numbers every fall and is no longer reviewed by the CBRC. All of the records above are of juvenile birds as have been all previous records. W»WVVLfc(r«- wilW- br*vs>- wdC - -UA, ^ VrmvL wT^ Cl4»irtV • ,11 ^ ^ Si^Kfrn. Wmwv?'^ . Figure 1. Mongolian Plover (Charadrius mongolus) (176-1980) 13 Sep 1980, Moss Landing, Monterey Co. , California. Sketches by Donna Dittmann CALIFORNIA BIRD RECORDS WHITE-RUMPED SANDPIPER {Calidris fuscicollis) . One (89-1978) 2-7 Jun 1978, Carmel River, Monterey Co. (JL; BE, RLeV, JM, VR, SW); photos on file. One (95-1978) 11 Jun 1978, Kehoe Beach, Marin Co. (RLeV). There are only two previous reports of this species in California, both from the Salton Sea during the first half of Jun. SEMIPALMATED SANDPIPER (Calidris pusilla). One juvenile (84-1977) 5 Aug 1977, Limantour Estero, Marin Co. (SJ, GP). One juvenile (119-1978) 9 Sep 1978, Ferndale Bottoms, Humboldt Co. (RAE, LE); photo on file. One juvenile (24-1979) 10 Sep 1978, Tijuana River Valley, San Diego Co. (DH, GMcC); photo on file. One juvenile (66-1979) 13 May 1979, Kern National Wildlife Refuge, Kern Co. (RW). One juvenile (67-1979) 24-27 May 1979, Tecopa, Inyo Co. (KVV). One juvenile (68-1979) 8 Aug 1979, Moss Landing, Monterey Co. (DR). Increased interest in studying shorebirds has indicated that this species is a regular migrant through California in both spring and fall. The species is no longer reviewed by the CBRC. BUFF-BREASTED SANDPIPER (Tr^/ngites subruficoliis) . Eleven (104-1978) 26-31 Aug 1978, Tomales Point, Marin Co. (TAB; AG, JM); photo on file. One (99-1978) 26-28 Aug 1978, Bodega Bay, Sonoma Co. (RAH, DAH; RAE, JM, BDP); photo on file. One (53-1979) 12 Sep 1979, Bodega Bay, Sonoma Co. (BDP). One (54-1979) 22 Sep 1979, Point Reyes, Marin Co. (BDP). This species is a rare to casual fall visitor to the coast of California between late August and mid-October. All the records are of juvenile birds. RUFF (Philomachus pugnax). One (82-1976) 16-17 Sep 1976, Eel River Bottoms, Humboldt Co. (DRu). One (120-1978) 3-4 Sep 1978, Limantour Natural Area, Marin Co. (AG, JM); photo on file. One (69-1979) 8-17 Sep 1979, Watsonville Sewage Plant, Santa Cruz Co. (DR). One (70-1979) 25 Sep- 11 Oct 1979, Zmudowski State Beach, Monterey Co. (DR; GMcC); photo on file. All of the records above are of juvenile birds. This species has proven to be a rare but regular fall migrant and winter visitant to California and is no longer reviewed by the CBRC. BLACK-HEADED GULL (Larus ridibundus). One adult (67-1978) 19-26 Feb 1978, Mad River Slough, Humboldt Co. (JD, GMcC, VR, DR). One adult (20-1979) 20-30 Mar 1979, Stockton Sewage Ponds, San Joaquin Co. (DR; JD, RAE, KG, GMcC, JM, BDP); photo on file. This gull is still an extremely rare straggler anywhere along the west coast of North America south of Alaska. The Humboldt Co. bird is only the sixth recorded in Califor- nia and the San Joaquin Co. bird the seventh. LITTLE GULL (Larus minutus). One adult (68-1978) 21-26 Feb 1978, Humboldt Bay, Humboldt Co. (JD, RAE, GMcC, VR, DR). One adult (108-1978) 7 Oct 1978, Humboldt Bay, Humboldt Co. (CH). One subadult (21-1979) 20 Mar-2 Apr 1979 and the next three winters, Stockton Sewage ponds, San Joaquin Co. (RAE; JD, KG, GMcC, JM, DR); photos on file. This species is most likely reaching the west coast of North America by an overland route from small widely scattered breeding colonies in central and eastern Canada. There are only seven records of this gull in California prior to 1978 and the species continues to be a rare straggler to the state. SANDWICH TERN (Sterna sandvicensis) . One adult (80-1980) 11-15 May 1980, San Diego Bay, San Diego Co. (JD, GMcC, PU). 6 CALIFORNIA BIRD RECORDS This is the first to be recorded in California (Schaffner, West. Birds 12:181-182, 1981). The species normally breeds around the Gulf of Mexico and along the southern parts of the Atlantic coast. However, some move across Central America in fall to winter on the Pacific coast, suggesting the route followed by the California bird. This bird was in an Elegant Tern nesting colony and was seen attempting to present fish to Elegant Terns. CRESTED AUKLET {Aethia cristatella) . One adult male specimen (Calif. Acad. Sci. 71070) (33-1979) 16-17 Jul 1979, Bolinas, Marin Co. (FW; BS); photos on file. This is the first recorded in California (Weyman, Condor 82:472, 1980). The species breeds on islands in the extreme northern Pacific, casually straying as far south as northern Japan in winter. The only other records along the Pacific coast of North America south of the general breeding areas in Alaska are a specimen (British Colum- bia Provincial Museum 11915) collected in the winter of 1892-1893 offshore from the northwestern part of Vancouver Island and the observation of an adult on 7 Jul 1980 near Cedros Island 300 miles south of the United States- Mexican border (Pitman et al.. West. Birds 14:47-48', 1983). GROOVE-BILLED ANI (Crotophaga sulcirostris) . One (23-1979) 13-17 Sep 1978, Anaheim, Orange Co. (DW; JD, DH, GMcC); photos on file. This is only the second to be found in California; the first was near Lakeview, River- side Co., 4-16 Nov 1974 (Am. Birds 29:122, 1975). SNOWY OWL (Nyctea scandiaca). One (61-1978) 24 Nov-2 Dec 1977, Humboldt Bay, Humboldt Co. (CH, GMcC); photos on file. Two (65-1978) 8 Jan-28 Feb 1978, Manila, Humboldt Co. (JD, LE, JM, DR, HS); photos on file. It is evident from reports along the northern Pacific coast (Am. Birds 32:249 and 392, 1978) that a number of Snowy Owls moved south along the Pacific coast during the late fall of 1977 and wintered as far south as extreme northern California. Figure 2. White-rumped Sandpiper (Calidris fuscicollis) (89-1978) 2 Jun 1978, Carmel River, Monterey Co. , California. Photo by Ron Branson 1 CALIFORNIA BIRD RECORDS BROAD-BILLED HUMMINGBIRD (Ci/nanthus latirostris) . One male (54-1978) 20-23 Sep 1977, Tijuana River Valley, San Diego Co. (GMcC). One male (84-1978) 9 Dec 1977-25 Jan 1978, Marina del Rey, Los Angeles Co. (JJ). This species is now being recorded in California every year and it is becoming evi- dent that small numbers regularly stray westward to California during fall to winter in the southern portion of the state. SULPHUR-BELLIED FLYCATCHER (Muiodiinastes luteioentris) . One (131-1978) 6-9 Oct 1978, Goleta, Santa Barbara Co. (LB; JD, PL, BSc); photo on file. This is only the second to be found in California. The first remained in Point Mugu State Park, Ventura Co., 22 Sep-5 Oct 1974 (Am. Birds 29:122, 1975). EASTERN PHOEBE (Savornis phoebe). One (59-1978) 29-30 Oct 1977, Oasis, Mono Co. (GMcC). This species has proven to be a regular visitor to California during fall and winter and is no longer reviewed by the CBRC. YELLOW-BELLIED FLYCATCHER (Empidonax flauiventris) . One banded (13-1977) 16 Sep 1976, S. E. Farallon Island, San Francisco Co. (RLeV); photos on file. This is the first to be recorded in California. This species breeds west to northeastern British Columbia, but normally migrates through the eastern portion of the United States. One collected in Tucson, Arizona, on 22 Sep 1956 (Phillips et al.. The birds of Arizona, 1964) is the only other documented record for the southwestern United States west of extreme eastern New Mexico. LEAST FLYCATCHER {Empidonax minimus). One (71-1977) 24 May 1977, Scotty’s Castle, Death Valley, Inyo Co. (DR). One (53-1978) 15 Sep 1977, Pt. Loma, San Diego Co. (BC, GMcC). One (56-1979) 6-7 Oct 1979, Pt. Reyes, Marin Co. (RS; AG, BDP); photos on file. This species is now recorded in small numbers every year, with most during fall. It is no longer reviewed by the CBRC. GREATER PEWEE (Contopus pertinax). One (129-1978) 25 Nov 1978-1 Mar 1979, Parker Dam, San Bernardino Co. (JD, DR). One or two of these birds are found wintering in California most years. The record above is undoubtedly the same individual (21-1978) as published in the Fourth Report of the CBRC (Luther, West. Birds 11:161-173, 1980). BLUE JAY {Ciianocitta cristata). One (62-1978) 31 Dec 1977-8 Jan 1978, Willow Creek, Humboldt Co. (LE, RAE); photo on file. One (66-1978) mid Jan-9 Mar 1978, Fieldbrook, Humboldt Co. (JD, RAE, JM, GMcC, VR, DR); photo on file. One (109-1978) 7 Oct 1978, north spit Humboldt Bay, Humboldt Co. (CH). There are now eight records of this species in California (Roberson, Rare birds of the West Coast, 1980). SEDGE WREN (Cistothorus piatensis). One (230-1980) 4 and 8 Nov 1980, Bolinas Lagoon, Marin Co. (DDeS; DN, PP, RS); photos on file. This is the first to be recorded in California. This species breeds west to central Saskatchewan, but moves southeastward in fall. It is previously unrecorded west of extreme eastern New Mexico in fall and winter. WOOD THRUSH {Hi;locichla mustelina). One (128-1978) 25-26 Oct 1978, Tijuana River Valley, San Diego Co. (JD, KG, DR). 8 CALIFORNIA BIRD RECORDS This is only the fourth to be found in California (Roberson, Rare birds of the West Coast, 1980). GRAY-CHEEKED THRUSH (Catharus minimus). One (46-1975) 25 Sep 1974, S. E. Farallon Island, San Francisco Co. (DDeS, RS); photos on file. This species is a casual fall straggler to California, with fewer than 10 acceptable records. DUSKY WARBLER (Ph\;lloscopus fuscatus) . One immature female specimen (P. f. fuscatus; Calif. Acad. Sci. 70314) (229-1980) 27 Sep 1980, S. E. Farallon Island, San Francisco Co. (RB, PP); photos on file. This is the first to be recorded in California. There are only three previous occur- rences of this Asiatic species reported for North America, one on St. Lawrence Island, Alaska, on 6 June 1977 (King etal.. Am. Birds 32:158-160, 1978), and two birds on Shemya Island, Alaska, on 18 Sep 1978 (one, P. /. fuscatus, collected; the other was present through 23 Sep) (Gibson, Condor 83:65-77, 1981). WHITE WAGTAIL (Motacilla alba). One first winter bird (130-1978) 9-11 Oct 1978, Goleta, Santa Barbara Co. (LB; JD, KG, PL, GMcC, DR); photo on file. One adult female (55-1979) 7 Aug-22 Sep 1979 and again from 20 Jul-21 Sep 1980, Watson- ville sewage plant, Santa Cruz and Monterey cos. (CF; SA, JD, RAE, AG, KG, GMcC, JM, BDP, DR); photos on file. These sightings establish the third and fourth records for California. The previous records were also during the fall (Oct) . The recently published paper by Morlan (Continental Birdlife 2:37-50, 1981) gives a detailed analysis of the distribution and identification of the two types of White Wagtail that have occurred in western North America, M. a. ocularis and M. a. lugens. Morlan reviews the systematics of the White Wagtail and presents evidence that lugens and ocularis are specifically distinct from one another (based on Soviet studies in which the two are said to breed sympatrically) . Morlan concludes that the Watsonville adult is definitely referable to lugens, while the Goleta bird and the previous two ac- cepted California records could not be assigned to subspecies. He concludes that, on the basis of all West Coast records, lugens is the more likely type to occur in California. The AOU Committee on Classification and Nomenclature has split these two types into distinct species (Auk 99(3): Suppl., 1982). The CBRC will reevaluate the previously accepted records. SPRAGUE’S PIPIT (Anthus spragueii). One (60-1978) 22 Nov 1977, Tijuana River Valley, San Diego Co. (GMcC). This is a casual straggler to California. The previous records are also from coastal southern California in fall. RED-THROATED PIPIT (Anthus ceruinus). One (58-1978) 13-15 Oct 1977, Tijuana River Valley, San Diego Co. (and crossed into Mexico) (GMcC). One (18-1979) 28 Sep 1978, San Nicolas Island, Ventura Co. (LJ; JD, RAE). Three (111-1978) 7-13 Oct 1978, Pt. Reyes, Marin Co. (LCB, AG, JM, BDP); photos on file. This species is now found almost annually in the fall in very small numbers. All records to date are from the coast and most are from southern California. WHITE-EYED VIREO (Vireo griseus). One (91-1978) 18-21 May 1978, Pt. Reyes, Marin Co. (JD, JM, VR). One singing male (63-1979) 31 May-2 Jun 1979, Oasis, Mono Co. (PL; GMcC). These are the third and fourth records for California. The previous are also in late spring (early Jun). 9 CALIFORNIA BIRD RECORDS YELLOW-THROATED VIREO (Vireo flavifrons) . One (127-1978) 28-30 May 1978, Oasis, Mono Co. (DR, PU). One (96-1978) 3 Jun 1978, Pt. Reyes, Marin Co. (KL, JM). This is a casual straggler to California, although it has been annual in recent years. Most records are for the spring. YELLOW-GREEN VIREO {Vireo flavouiridis). One (110-1978) 22-25 Oct 1978, Lake Merced, San Francisco Co. (LCB, AG, JM, BDP, DR); photo on file. This is the first record of this species for northern California. There are about 10 fall records from southern California. Most authorities now regard the Yellow-green Vireo as conspecific with the Red-eyed Vireo (V. oliuaceus; Auk 99(3): Suppl., 1982). PHILADELPHIA VIREO {Vireo philadelphicus) . One (8-1979) 30 Dec 1978-12 Jan 1979, Palos Verdes Peninsula, Los Angeles Co. (LH; JD, KG, GMcC). One (64-1979) 26 Oct 1979, Carmel River mouth, Monterey Co. (DR). This species is now noted annually in California, with the great majority of records in fall. The bird on the Palos Verdes Peninsula is the first winter record of this species in California. PROTHONOTARY WARBLER {Protonotaria citrea). One male (48-1978) 6-7 Jun 1977, Tijuana River Valley, San Diego Co. (GMcC). One female (41-1979) 30 Dec 1978-10 Mar 1979, Santa Barbara, Santa Barbara Co. (KG; JD, PL), One (60-1979) 23 May 1979, Oasis, Mono Co. (KVV, PL). This species is now recorded annually in both the late spring and fall. The sighting from Santa Barbara is the first of a wintering bird in California. WORM-EATING WARBLER {Helmitheros uermivorus). One (94-1978) 11-21 Jul 1978, Tilden Park, Contra Costa Co. (PG; JM, VR, DR). One (106-1978) 5-8 Oct 1978, Pt. Reyes, Marin Co. (AG, JM, BDP, JW); photo on file. This is a casual vagrant to California, with most records being in fall. The Tilden Park sighting is the second midsummer record in California. GOLDEN- WINGED WARBLER {Vermivora chr{^soptera) . One male (28-1979) 24 May 1979, Scotty’s Castle, Death Valley, Inyo Co. (KVV: PL, DR); photo on file. This is a casual vagrant to California, with records being about equally divided be- tween late spring and fall. CERULEAN WARBLER {Dendroica cerulea). One (113-1978) 15-17 Oct 1978, Pt. Reyes, Marin Co. (JW; DH, AG, JM, SW); photos on file. One female (116-1978) 27 Oct 1978, Carmel River mouth, Monterey Co. (SFB). One female (46-1979) 26-27 May 1979, Pt. Loma, San Diego Co. (CE; PU) . One male (62-1979) 25 Oct 1979, Carmel River mouth, Monterey Co. (DR). There are only three previous California records of this species. The Pt. Loma sighting is only the second spring record for California. YELLOW-THROATED WARBLER {Dendroica dominica). One male (48-1979) 19-21 May 1978, Long Beach, Los Angeles Co. (JA; JD). One (122-1978) 2 Sep 1978, Red Bluff, Tehama Co. (SL). One male (47-1979) 29 Apr 1979, Encinitas, San Diego Co. (L and SS). One male (31-1979) 23 Jun-3 Jul 1979, Pt. Reyes, Marin Co. (JM, PU). The above records are referable to the white-lored subspecies, D. d. albilora. In re- cent years this species has been reported annually. Most records are for spring and from southern California. 10 CALIFORNIA BIRD RECORDS GRACE’S WARBLER (Dendroica graciae). One (55-1978) 24-25 Sep 1977, Tijuana River Valley, San Diego Co. (GMcC). This species is a casual straggler to California. Three of the six previous occurrences were also of fall birds from coastal San Diego Co. PINE WARBLER (Dendroica pinus). One male (36-1979) 4-26 Feb 1978, Regina, Imperial Co. (KG; JD, GMcC). This is a casual straggler to California (fewer than 10 records) . All previous records have been from fall (mostly October) and most have been from southern California. The above record is the first for the winter period and the first interior record. Fall Blackpoll Warblers continue to be confused with the Pine Warbler. Observers are therefore urged to use extreme caution before reporting this species in California. CONNECTICUT WARBLER (Oporonis agiJis]. One (43-1979) 14 Sep 1978, San Diego, San Diego Co. (RR). One (115-1978) 22 Oct 1978, Santa Cruz, Santa Cruz Co. (DP). This is a casual vagrant to California. Almost all records of this species are coastal and the majority are for the fall period. The Santa Cruz record above is the latest record for the state . RED-FACED WARBLER (Cardellina rubrifrons). One (47-1978) 21-24 May 1977, Pt. Loma, San Diego Co. (DH, GMcC); photo on file. Two (39-1979) 17 Jun-3 Jul 1978, San Gabriel Mts., Los Angeles Co. (JA, KG); photo on file. These are the fourth and fifth records of this species for California. The Pt. Loma sighting is the first coastal record accepted by the CBRC. The record from the San Gabriel Mts. is from a plausible breeding locality. It was unclear as to whether or not these birds represented a mated pair (neither bird was identified to sex). HOODED WARBLER (Wilsonia citrina). One male (123-1978) 14 Nov-7 Dec 1978, Muir Woods, Marin Co. (RAE, AG, JM); photo on file. One female (56-1978) 17 Dec 1977-27 Jan 1978, San Diego, San Diego Co. (GMcC). This species is now noted annually in California in very small numbers (mostly in spring) and is no longer being reviewed by the CBRC. The San Diego sighting is the first winter record for California, although there is a winter record from Washington. CANADA WARBLER (Wi7son/a canadensis). Two (51, 52-1978) 11-13 Sep 1977, Tijuana River Valley, San Diego Co. (GMcC). One (117-1978) 10 Sep 1978, Pt. Saint George, Del Norte Co. (RAE). One male (112-1978) 12-22 Oct 1978, Pacific Grove, Monterey Co. (VY; JM). This species is now being found every fall in very small numbers. The great majority of these records are from the immediate coastal slope. There are also a few spring records. This species is no longer being reviewed by the CBRC. COMMON GRACKLE (Quiscalus quiscula). One (27-1979) 25 May 1979, West Pittsburg, Contra Costa Co. (RAE, SF). This species is a casual straggler to California (about 10 previous records) . The date of the above sighting fits the pattern of late spring occurrences of this species, but the sighting represents one of the few records from northern California. As expected, all of the California records appear to pertain to the “Bronzed” subspecies, Q. q. versicolor. SCARLET TANAGER (Piranga oliuacea). One male banded (78-1979) 15 Oct 1979, Bolinas, Marin Co. (RS). This species is a very rare straggler to California, but has been recorded annually in recent years. The majority of records are from rather late in the fall period and are from southern California. 11 CALIFORNIA BIRD RECORDS WHITE-WINGED CROSSBILL (Loxia leucoptera). Flock of 12 (5-1979) 1 Sep 1978, Mosquito Lake, Trinity Co. (GG, PG). This is the first record for California. This erratic species staged an invasion in the winter of 1977-78 into Washington and Oregon with observations continuing through the spring, summer and fall of 1978. CASSIN’S SPARROW (Aimophila cassinii). Up to 15 singing males (126-1978) 21 May-7 Jun 1978, Lanfair Valley, San Bernardino Co. (DR). The occurrence of the above concentration coincided with an invasion by this species into the Southwest in spring 1978 (Am. Birds 32:1043, 1978). There are only eight previous records of this species for California, all of single birds. Additional records from spring 1978 from elsewhere in southern California are currently cir- culating through the CBRC. SHARP-TAILED SPARROW (Ammospiza caudacuta) . One (79-1978) 8 Feb 1978, Palo Alto, Santa Clara Co. (AG, JM, MW); photos on file. Two (22-1979) 10 Jan 1979 (one bird) and 27 Jan 1979 (two birds), Dumbarton Marsh, Alameda Co. (RAE). One (14-1979) 25 Jan-24 Feb 1979, Palo Alto, Santa Clara Co. (JM). This species regularly winters in very small numbers at a few of the larger coastal estuaries. SNOW BUNTING (Plectrophenax niualis). One male (107-1978) 11 May 1978, Cape Mendocino, Humboldt Co. (CH); photo on file. One (7-1979) 14 Nov-2 Dec 1978, MacKerricher Beach, Mendocino Co. (JP, KVV); photos on file. One (35-1979) 23-27 Dec 1978, Kelso Valley, Kern Co. (JD, KG). This species is now recorded annually in the late fall and early winter in northern California and is no longer being reviewed by the CBRC. The sighting from Cape Mendocino establishes the first spring record for the state and must be one of the latest records for the lower contiguous 48 states. The Kelso Valley sighting is the third record for southern California. UNACCEPTED RECORDS, Identification uncertain YELLOW-BILLED LOON (Gavia adamsii). One (52-1976) 5-9 May 1976, Pt. Mugu, Ventura Co. LEAST GREBE {Tachiibaptus dominicus) . One (38-1979) 1 Oct 1978, Salton City, Imperial Co. CAPE PETREL (Daption capense). One (33-1974) 13 Mar 1974, Monterey Bay, Monterey Co. WILSON’S STORM-PETREL {Oceanites oceanicus). One (58-1976) 9 Oct 1976, Monterey Bay, Monterey Co. WHITE-BELLIED STORM-PETREL (Fregetta grallaria). One (43-1978) 1 Oct 1977, Monterey Bay, Monterey Co. YELLOW-CROWNED NIGHT-HERON (Nyctanassa uiolacea). One (102-1978) 5 Jul 1977, Tomales Bay, Marin Co. 12 CALIFORNIA BIRD RECORDS UNACCEPTED RECORDS, Identification uncertain (Cont.) TRUMPETER SWAN (Cf^ngus buccinator). Five (41-1977) 31 Dec 1967, Santa Rosa, Sonoma Co. ZONE-TAILED HAWK (Buteo albonotatus) . One (52-1979) 8 Sep 1979, Watson- ville, Santa Cruz Co. HARRIS’ HAWK {Parabuteo unicinctus). One (37-1979) 24 Sep 1978, north of Blythe, Riverside Co. GREAT CRESTED FLYCATCHER (Mi^iarchus crinitus). One (165-1977) 25 Aug 1972, near Rodeo Lagoon, Marin Co. EASTERN PHOEBE (Sayorni's phoebe). One (32-1977) 7 Sep 1971, Yucca Valley, San Bernardino Co. One (86-1976) 29 Aug 1976, Lafayette, Contra Costa Co. LEAST FLYCATCHER {Empidonax minimus). One (58-1977) 27 May 1977, Scotty’s Castle, Inyo Co. EASTERN WOOD-PEWEE (Contopus uirens). One (93-1976) 5 Jun 1969, Pacific Grove, Monterey Co. GRAY CATBIRD (Dumetella carolinensis) . One (75-1978) 2 Oct 1977 Pacific Grove, Monterey Co. VEERY (Catharus fuscescens) . One (26-1979) 10 May 1979, San Rafael, Marin Co. NORTHERN WHEATEAR {Oenanthe oenanthe). One (101-1978) 14 Dec 1977, Death Valley National Monument, Inyo Co. YELLOW WAGTAIL {Motacilla flava) . One (93-1978) 2 Dec 1977, Mare Island area, Solano Co. RED-THROATED PIPIT {Anthus cervinus). One (42-1978) 4 Sep 1977, Pt. Reyes, Marin Co. One (103-1978) 28 Sep 1977, Grizzly Island, Solano Co. One (73-1979) 7 Nov 1979, Auburn, Placer Co. PHILADELPHIA VIREO {Vireo philadelphicus) . One (134-1977) 23 Aug 1973, Cow Creek, Death Valley, Inyo Co. One (49-1979) 22 Oct 1978, Pt. Loma, San Diego Co. PLAIN CHACHALACA (Ortalis vetula). One (57-1979) 28 Nov 1976, Bakersfield, Kern Co. YELLOW RAIL (Coturnicops noueboracensis) . One (74-1978) 4 Feb 1978, Santee Lakes, San Diego Co. GREATER GOLDEN-PLOVER (Pluuialis apricaria). One (3-1979), 2 Jan 1966, near Dillon Beach, Marin Co. JACK SNIPE {Li/mnocr\^ptes minimus). One (76-1978) 23 Jan 1977, Oakland, Alameda Co. 13 CALIFORNIA BIRD RECORDS UNACCEPTED RECORDS, Identification uncertain (Cont.) SHARP-TAILED SANDPIPER (Calidris acuminata). One (46-1977) 3 Sep 1968, Ab- bott’s Lagoon, Marin Co. One (48-1977) 19 Oct 1973, Limantour Estero, Marin Co. Three (119-1977) 25 Oct 1977, Lake Talawa, Del Norte Co. SEMIPALM ATED SANDPIPER (Calidris pusilla). Two (52-1977) 6-10 Aug 1975, Areata bottoms, Humboldt Co. One (78-1976) 23 Aug 1975, Wister Unit, Imperial Wildlife Area, Imperial Co. One (51-1979) 15 Jun 1979, Pajaro River, Santa Cruz Co. RUFF (Philomachus pugnax). One (96-1977) 12 Sep 1977, Lake Talawa, Del Norte Co. One (36-1978) 20 Sep 1977, Goleta, Santa Barbara Co. One (42-1979) 20 Dec 1978, Tecopa Hot Springs, Inyo Co. SNOWY OWL (Nyctea scandiaca). One (25-1978) 20 Nov 1972, near Samoa, Hum- boldt Co. One (77-1978) 17 Jun 1976, near Oakland, Alameda Co. Figure 3. Dusky Warbler (Phylloscopus fuscatus) (229-1980) 27 Sep 1980, S. E. Far- allon Island, San Francisco Co. , California. Photo by Bob Boekelheide 14 CALIFORNIA BIRD RECORDS UNACCEPTED RECORDS, Identification uncertain (Cont.) RIVOLl’S HUMMINGBIRD (Eugenes fulgens). One (34-1979) 4 May 1978, near Riverside, Riverside Co. CERULEAN WARBLER (Dendroica cerulea). One (45-1979) 22 Oct 1978, Pt. Loma, San Diego Co. PINE WARBLER (Dendroica pinus). One (108-1977) 25 Sep \911 , Pacific Grove, Monterey Co. CONNECTICUT WARBLER (Oporornis agilis). One (154-1977) 12 Sep 1973, Paradise, Butte Co. One (133-1977) 6 Oct 1977, Pt. Reyes, Marin Co. COMMON GRACKLE (C?u/sca(us quiscula). One (10-1978) 13 Oct 1977, Hayward, Alameda Co. SHARP-TAILED SPARROW (Ammospiza caudacuta). One (152-1977) 24 Dec 1973. Pt. Reyes, Marin Co. UNACCEPTED RECORD, Origin uncertain (Identification ac- cepted) HARRIS’ HAWK (Parabuteo unicinctus). One (72-1978) 16 Jan 1978, Mecca, River- side Co. Figure 4. Snow Bunting (Plectrophenax nivalis) (107-1978) 11 May 1978, Cape Mendocino, Humboldt Co., California. Photo by Craig Hohenberger 15 CALIFORNIA BIRD RECORDS CONTRIBUTORS Steve Allison (SA), Aileen Anderson (AA), Jon Atwood (JA), Stephen F. Bailey (SFB), Bernice Barnes (BBa), Fred Barry (FB), Louis Bevier (LB), Laurence C. Bin- ford (LCB), Tupper Ansel Blake (TAB), Robert Boekelheide (RB), Betty Boyd (BB), Bruce Broadbooks (BBr), Elizabeth Copper (EC), Bart Cord (BC), Brian Daniels (BDa), David DeSante (DDeS), Bruce Deuel (BD), Donna Dittmann (DD), Jon Dunn (JD), Claude Edwards (CE), Bruce Elliot (BE), Victor Emanuel (VE), Linda Erickson (LE), Richard A. Erickson (RAE), Jules Evens (JE), Kurt Fankhauser (KF), L. P. Far- rar (LF), Fran Floyd (FF), Steven Foreman (SF), Carolyn Frederiksen (CF), Gary Friedrichsen (GF), Jeff Froke (JF), Kimball Garrett (KG), Steve Gellman (SGe), Stephen R. Getty (SRG) , A1 Ghiorso (AG), Doug Gomke (DG) , Geoff Gordon (GG), Philip Gordon (PG), L. W, Gralapp (LWG), V. Lee Grover (LG), Pamela M. Gunther (PMG), Linda Hale (LH), Roger Harris (RH), Andreas Helbig (AH), Phil Henderson (PH), Norman Hill (NH), Don Hoechlin (DH), R. W. Hoellwarth (RWH), Craig Hohenberger (CH), Dave Holdridge (DHo), David A. Holway (DAH), Richard A. Holway (RAH), Jerome A. Johnson (JJ), Stu Johnston (SJ), Lee Jones (LJ), Abigail King (AK), Kathleen Lackey (KL), Jeri Langham (JL), Steve Laymon (SL), Paul Lehman (PL), Ron LeValley (RLeV), Ian MacGregor (IMacG), Alayne MacMillan (AM), Bill Marshall (BM), Robert E. Maurer (REM), G. Charles Mayes (GCM), Guy McCaskie (GMcC), J.E. McDonald (JMcD), Joan Mills (JMi), Joseph Morlan (JM), Scott Moorhouse (SM), Dan Nelson (DN), Gary Page (GP), Dennis Parker (DP), Ben- jamin D. Parmeter (BDP), John Parmeter (JP), Joyce Parry (JPa), Raphael Payne (RP), Elizabeth Phinney (EP), William Pursell (WP), Peter Pyle (PP), William Reese (WR), Van Remsen (VR), Patricia M. Righter (PMR), Don Roberson (DR), Raymond Robinson (RR), Dave Rudholm (DRu), Luis and Suzanne Santaella (L and SS), Starr Saphir (SSa), Buzz Scher (BSh), Brad Schram (BSc), Genevieve Sears (GS), John Smail (JS), Arnold Small (AS), Bruce Sorrie (BS), Larry Spear (LS), Richard Stallcup (RS), Lynn Stenzel (LSt), Robert M. Stewart (RMS), Shumway Suffel (SS), Gerald Tolman (GT), Blaine Ulmer (BU), Philip Unitt (PU), Kent Van Vuren (KVV), Richard Webster (RW), Fred O. Weyman (FW), Ralph S. Widrig (RSW), Mike Wihler (MW), Douglas R. Willick (DW), Steve Wilson (SW), Vernal Yadon (VY). Accepted 28 March 1 983 Cook’s Petrel 16 Sketch by Tim Manolis HYBRIDIZATION OF A BLUE-THROATED HUMMINGBIRD IN CALIFORNIA FRANK A. BALDRIDGE, LLOYD F. KIFF, SUSAN K. BALDRIDGE, and ROBERT B. HANSEN, Western Foundation of Vertebrate Zoology, 1100 Glendon Avenue, Los Angeles, California 90024 A relatively large number of North American hybrid hummingbirds have been described (Banks and Johnson 1961, Short and Phillips 1966, Mayr and Short 1970), representing at least 12 hybrid combinations, mostly inter- generic (Wells et al. 1978). Nearly all known hybrids have been adult males, and the evidence for their presumed hybrid origin has been based primarily upon the external characters of specimens. In late December 1977 a female Blue-throated hummingbird (Lampornis clemenciae) was discovered visiting a feeder near Three Rivers, Tulare Coun- ty, California. This bird, the first of the species recorded in California (Luther et al. 1979), subsequently nested twice in the vicinity. Because of the ap- parent absence of a male Blue-throated Hummingbird, as well as certain char- acteristics of the young, we believe that these nesting attempts involved hy- bridization. In the following account the nesting attempts and the resultant off- spring are described, and the possible identity of the male parent is discussed. We are unaware of a previous report of a hummingbird hybridization discov- ered during the nesting stage. THE BLUE-THROATED HUMMINGBIRD IN CALIFORNIA The female Blue-throated Hummingbird was first seen about 28 December 1977 by Gertrude Schuckert at a feeder at her home on Heidi Road, 3 km S of Three Rivers. The bird returned to the feeder daily and was photographed on 16 January 1978 by F. A.B. It remained in the vicinity throughout the winter, and on 30 April it was captured, photographed, measured and released by F.A.B. and R.B.H. It was last seen in the area on 27 May 1978. The species normally breeds from the southwestern United States south to the state of Oaxaca, Mexico (AOU 1957). Within the United States the subspecies L. c. bessophilus breeds in isolated mountain ranges of south- eastern Arizona (Phillips et al. 1964) and extreme southern New Mexico (Hubbard 1978) . The nominate race ranges north to southwestern Texas and probably breeds there, although actual nesting has not been documented (Oberholser 1974). The species normally winters in the Mexican lowlands (AOU op cit.). The two races can probably be separated only by the intensity of the green coloration of the dorsum and the gray coloration of the underparts, bessophi- lus being generally paler (Mayr and Short 1970). After examining large series of Blue-throated Hummingbird skins in the Museum of Vertebrate Zoology (University of California, Berkeley), California Academy of Sciences and Western Birds 14: 17-30, 1983 17 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION Western Foundation of Vertebrate Zoology, we agree with Van Tyne (1953) that measurements are of little use in distinguishing the two forms. As we did not have comparative material available when the Three Rivers blue-throat was in hand, its subspecific identity could not be determined and inferences about its region of origin therefore could not be drawn. STUDY AREA The female blue-throat wintered on the canyon floor of the South Fork of the Kaweah River, 3 km S of Three Rivers, where the elevation is about 300 m. Sycamores (Platanus racemosa), Fremont Cottonwoods (Populus fre- montii) , and Valley and Interior Live oaks (Quercus lobata and Q. wislizenii) dominate the overstory; the understory is primarily scattered Whiteleaf Man- zanitas (Arctostaphi/los uiscida) and Wedgeleaf Ceanothus (Ceanothus cuneatus). This riparian woodland is associated with Digger Pine (Pinus sabi- niana) -oak woodlands of central California. Marshall (1957) noted a basic similarity of the breeding avifauna of the pine-oak woodlands of southeastern Arizona and the Digger Pine-oak woodlands of central California. Certainly the canyon is physiognomically similar to the canyons of southeastern Arizona where the blue-throat is a summer resident. Average annual rainfall in the area is 331 mm (records from nearby Kaweah Lake), but is highly variable. The winter of 1976-1977 was the driest on record, whereas the winter of 1977-1978 was the wettest. Minimum temperatures recorded in January and February 1978 were significantly higher than those recorded in 1977. BEHAVIORAL OBSERVATIONS The Blue-throated Hummingbird’s wintering activity was centered about an Interior Live Oak in which a feeder was suspended. The feeder and the live oak in which the blue-throat normally perched and roosted usually were defended. The bird’s sugar solution diet was supplemented by insects, which were relatively abundant because of the wet, mild winter. She collected insects near the feeder tube and in short erratic flights, similar to those described by Wagner (1946), over an adjacent small marsh. During late February and early March the female was observed less often in the vicinity of the feeder. The reason for the bird’s frequent absences became apparent on 12 March when it was found on a nest 270 m NW of the feeding station. The nest was built around a telephone wire approximately 3 m off the ground under the west-facing eaves of a residence (Figure 1). The house is situated on a dry, steep hillside above the belt of riparian vegetation where the bird had confined its winter activities. Observations were made intermittently at the site throughout the nesting period, often with a second observer sta- tioned at the riparian feeding station. 18 Figure 1. Female Blue-throated Hummingbird (Lampornis clemenciae) feeding young of first clutch, Three Rivers, Tulare Co., California, 13 April 1978. Mirror above was used to check development of young. Photo by Frank Baldridge BLUE-THROATED HUMMINGBIRD HYBRIDIZATION When found, the nest contained two eggs, although it was as yet unlined. During the remainder of the incubation period, the bird added a lining, con- sisting of bits of thread and feathers from her own abdomen. Details of the bird’s incubation behavior are summarized in Table 1. Constancy of incuba- tion was calculated to be 84% (Skutch 1962), somewhat higher than the figures the same author reported for five neotropical hummingbird species (range 65-81 %) . During her absences from the nest, the female usually visited the riparian feeding station for periods ranging from 2 to 7 minutes. Three days prior to hatching of the eggs, the amount of time spent at the feeders per visit declined from a mean of 3.75 minutes (S.D. ± 1.9) to a mean of 1.91 minutes (S.D. ± 0.67) , as the bird began spending relatively more time forag- ing for insects near the nest. Furthermore, the female appeared to be more restless while she was on the nest during the late stages of incubation. She was also more aggressive towards other birds in the immediate vicinity of the nest, especially near a Ceanothus shrub where she perched regularly. The first egg hatched before 1045 on 26 March. At that time the female was unusually aggressive at the nest, and the site was not visited again until 28 March. By then the second egg had hatched, and the size difference between the young suggested that hatching was asynchronous. Table 1 . Incubation behavior and weather conditions during first and second nesting at- tempts of a Blue-throated Hummingbird at Three Rivers, California. First Clutch Second Clutch Incubation behavior Attentive periods (min) Mean 35.0 52.6 N 11 23 S.D. ±15.1 ±38.8 Range 15-61 22-179 Inattentive periods (min) Mean 6.6 10.0 N 11 23 S.D. ±6.5 ±12.2 Range 2-16 1-63 Time attentive (%) 81 84 Weather conditions during observation periods Temperature range (C°) 16-22 10-37 Precipitation Days 7 0 Amount (mm) 70 0 Observation periods 4 11 Total hours observed 10.8 28.5 20 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION Aspects of the female’s care of the young are summarized in Table 2. Mid- day brooding ceased on the 10th day after the first young hatched, and early morning brooding was not observed after the 16th day, when the young were well feathered. Our limited data suggest that the rate at which the young were fed did not change significantly during the nesting period, thus agreeing with Wagner’s (1952) observations of nesting Blue-throated Hummingbirds in Mexico. On 16 April the nestlings were removed from the nest, photographed, banded, marked on the back with red and blue paint, respectively (cf. Stiles and Wolf 1973) , and returned to the nest. They fledged on the following day, 21 days after the first young hatched. This is markedly shorter than the nest- ling periods of 24-29 days recorded by Wagner (1952) for this species in Mex- ico. On the day of hatching two hummingbird feeders were placed about 30 m from the nest site, and the female blue-throat ceased visiting the riparian feeding station. After fledging, the young remained in nearby shrubs, where they were fed by the female. Within a week they were exploring the general vicinity and apparently gleaning insects from vegetation, but they were still be- ing fed periodically by the female. By 29 April both nestlings were using the feeders that had been placed near the nest site. Table 2. Parental care during first nesting attempt of female Blue-throated Hum- mingbird . Week #1 Week n Week #3 Midday brooding behavior Attentive periods (min) Mean 26.0 6.4' N 11 4 S.D. ±13.0 ±7.4 Range 15-60 4-18 Inattentive periods (min) Mean 15.0 27.3 N 11 4 S.D. ±5.6 ±15.8 Range 7-24 16-48 Time attentive (%) 48 19 Midday feeding intervals (min) Mean 46.0 34.3 48.9 N 10 6 7 S.D. ±14.6 ±14.5 ±13.3 Range 40-75 19-52 26-65 Total minutes observed 597 155 396 ^Midday brooding ceased on day 10. 21 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION The young were recaptured on 30 April and photographed. On this date two rectrices were removed from the tail of each fledgling for diagnostic pur- poses; these are now on deposit at the Western Foundation of Vertebrate Zoology. One of the young was last seen in the nesting area on 11 May, whereas the other remained until at least 17 May. Four days after the first brood fledged, the blue-throat began refurbishing the nest with bits of green moss. Ten days later (2 May) the first egg of a sec- ond clutch was laid. Incubation did not commence until a second egg was laid on 4 May. Hatching of the two eggs was asynchronous, occurring on 20 and 21 May after 17 and 18 days of incubation, respectively. Identical incubation periods were found for this species in Mexico by Wagner (1952) . As with the first clutch, the female continued to add various material, including thread, bits of wool from a discarded blanket, and her own feathers, to the nest lining throughout the incubation period. Percent attentiveness was identical during the two incubation periods, but there was significant (p = 0.05) variation in the length of attentive and inat- tentive periods between the two clutches (Table 1) . Unusually long periods of incubation and inattentiveness occurred in the late afternoons during the sec- ond period, coinciding with temperatures of over 35° in the nest vicinity. Dur- ing the same period, the blue-throat employed different insect foraging methods. Whereas insects had previously been collected while the bird hovered over Ceanothus flowers, during this period foliage gleaning and several successful attempts at hawking alfalfa butterflies (Pieridae) were observed. On 21 May the female revisited the riparian feeding station area after a long absence and was observed collecting insects there. During the first 2 days of the second nestling period, intervals between feedings averaged significantly longer (59 vs. 46 minutes) than those ob- served with the first brood (Table 2) , and this may have been a further indica- tion of insect scarcity in the area at that time. On 24 May an unusually long in- attentive period was observed at the nest, and the female did not appear at the nest site at all on 25 May. Examination of the nest on that date revealed that the nestlings had died probably 1-3 days after hatching. The female blue- throat continued to visit the riparian feeding station at half hour intervals until 27 May; she was not seen thereafter in the Three Rivers area. DESCRIPTION OF OFFSPRING FROM FIRST NESTING When the hybrid offspring from the first nesting were recaptured on 30 April the red-marked fledgling had an exposed culmen length of 15.6 mm, a wing chord of 54.5 mm, and it weighed 3.2 g. The blue-marked bird had an ex- posed culmen of 16.7 mm, a wing chord of 57. 1 mm, and it weighed 3.5 g. The ramphotheca of the upper mandible of both birds exhibited the corruga- tions that are diagnostic of juvenile hummingbirds (Ortiz-Crespo 1972). 22 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION The markings on the side of the head and throat varied in intensity between the two fledglings and between the sides of the head on each individual. The red-marked bird had a definite white postocular dot with an indistinct white postocular line which was partly obscured by darker auricular feathers. A faint rictal line formed by the off-white dorsal margins of the malar feathers was also present. The blue-marked bird lacked a rictal line on the left side of the head, but showed a distinct postocular stripe on that side. The pattern was essentially reversed on the right side of the head with a definite rictal line being present, but with the postocular stripe being indistinct. The throat of each bird was dark gray with the central portion of these feathers being green under proper light. Each throat feather had a well- defined thin white margin . The breasts and abdomens of the birds were lighter gray than the throat with scattered bronzy green flecks on the grayish flanks. The undertail coverts were gray with whitish edges. There was no rufous on the underparts or on the rectrices. None of the remiges or rectrices exhibited the sort of emargination that is typical of the genera Calypte or Archilochus. The blue-marked bird was recaptured 21 October, by which time it had nearly completed the post-juvenal molt. On that date the bird weighed 3.52 g, had a wing chord of 58.0 mm, exposed culmen of 20.2 mm, and a tail length of 30.0 mm (Table 3) . By this time it lacked the bill corrugations observed in April. Rectrices 3, 4 and 5 were collected from the bird on this date and were also deposited in the WFVZ collection for identification purposes. The mark- ings on the side of the head were similar to those observed in April with the ric- tal line still lacking on the left side, but with a broad, distinct postocular stripe. On the right side only a postocular dot was distinct. An indistinct whitish line extended posteriorly from the dot and was mostly obscured by auricular feathers. Two white malar feathers formed a rictal dot below the lores. The ap- pearance of the underparts was little changed from the juvenal plumage observed in April; there was still no rufous on the underparts or tail. In general, the fledglings resembled the adult female Blue-throated Hum- mingbird in color, although the head markings were indistinct in some areas. However, the young were strikingly smaller than the female parent (Table 3) , offering strong support to our assumption that the mating was hybrid in nature. At the time of its recapture the blue-marked bird had been observed intermittently at the riparian feeding station for several days. In confrontations with other hummingbirds, it was invariably subordinate. The hybrid had a markedly slow wingbeat, apparently the result of its relatively long wings and small body size, and its flight was somewhat butterfly- like. IDENTIFICATION OF THE MALE PARENT Juvenile hummingbirds often are difficult to identify and establishing the parentage of juvenile hybrids is potentially even more difficult. Male second- ary sexual characteristics, which have generally been used to detect previous hybrids, were lacking in the offspring of the first hybrid nesting, and the young 23 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION from the second nesting did not survive long enough to develop any recognizable characters. Furthermore, the size discrepancy between the Blue- throated Hummingbird and all potential mates of other species makes measurements and weights of the offspring virtually useless for diagnostic pur- poses. Therefore, we have relied mainly on known distribution, breeding phenology, and minor plumage characteristics in attempting to identify the male parents of the hybrid offspring. The following discussion is restricted to hummingbird species that normally breed in California. Calypte anna: Anna’s Hummingbird is the most common local humming- bird species, and it is the only one that is a permanent resident in the Three Rivers area. The species breeds as early as December in California (Stiles 1973} and at the time of the first hybrid nesting, local male Anna’s Humming- birds were establishing breeding territories. The hybrid offspring resembled Cal^^pte anna in the color of the interramal region and underparts, and the tails of the hybrids were similar to Anna’s in color and shape (Figure 2) . However, the hybrids lacked the shallow “W” in- dentation typical of the tip of the adult secondaries of Anna’s Hummingbirds (Williamson 1956) , and they weighed 0.2 g less than the lightest Calypte anna weighed locally under similar conditions (Table 3, Figure 3). Calypte costae: Costa’s Hummingbird has not been recorded at Three Rivers, and we know of only three records for Tulare County. However, one is of an adult male that wintered in 1978-1979 in Dinuba, 35 mi NW of Three Rivers. There are no breeding records for the general area. Elsewhere in the state, Costa’s Hummingbirds breed from about January to March in desert areas and from late March to May in coastal chaparral habitats (Stile^pers. comm.) . The hybrids were similar in color to juvenile Costa’s Hummingbirds, although the latter species is generally somewhat paler on the underparts. The hybrids weighed slightly more than normal Costa’s Hummingbirds (Table 3, Figure 3) . A Lampornis clemenciae x Cal\;pte costae hybrid has been reported previously (Mayr and Short 1970). This bird is a juvenile male (University of Arizona 9359) that was found in a mummified condition in the Huachuca Mountains in southeastern Arizona on 26 April 1968. We examined this specimen and found that its measurements (wing chord 59 mm, exposed culmen 20.3 mm) are virtually identical to those of the blue-marked hybrid from Three Rivers (Table 3). Archilochus alexandri: The Black-chinned Hummingbird is a common summer resident in the Three Rivers area, but it arrives later (about the first week of April) than the date of the first hybrid nesting. No Black-chinned Hummingbirds were seen in the study area until after the first clutch had hatched. There is nothing about the color of the hybrids that is incompatible with black-chin parentage, and the weight of the blue-marked bird was very close to mean black-chin weight (Table 3, Figure 3). The acuteness of the outer rectrices of the hybrids relative to those of the adult female blue-throat may be due to the influence of A. alexandri. However, the emargination of 24 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION 25 Figure 2. Tails of the female Blue-throated Hummingbird, the hybrid, and females of possible parental species. BLUE-THROATED HUMMINGBIRD HYBRIDIZATION these feathers, characteristic of adult female and juvenile male Black-chinned Hummingbirds (Baldridge 1983) , was not evident. Other factors in addition to the timing of the first nesting attempt tend to rule out a black-chin parent, especially the short bill length of the blue- marked hybrid in October (Figure 3) . During the period when the blue-throat was refurbishing the nest in prepar- ation for the second nesting attempt, Black-chinned Hummingbirds were the most common species in the area. On several occasions during this period, in- dividual male black-chins were seen displaying to the perched female blue- throat. However, the nestlings of this second attempt died before enough plumage had developed to permit identification of the male parent. Selasphorus and Stellula species; Though it is possible that male Selasphorus hummingbirds might occur in the study area at about the time of the first hybridization, a Rufous Hummingbird (Selasphorus rufus) then would be unusually early (Short and Phillips 1966) and an Allen’s Hummingbird (Selasphorus sasin) would be a vagrant (Phillips 1975). Calliope Humming- birds (Stellula calliope) normally arrive in the southern Sierra Nevada later than the first nesting attempt (Grinnell and Miller 1944) and have not been recorded in the Three Rivers area. Perhaps more importantly, some rufous coloration has been evident in the tails of all known hybrids involving Selasphorus or Stellula parentage (Banks and Johnson 1961, Lynch and Ames 1970) , and these genera can probably be eliminated from consideration on this basis alone. Table 3. Mensural characteristics of the female Lampornis clemenciae, hybrid (X18371, 21 Oc- tober 1978), and females of possible parental species. L. clemenciae Hybrid C. anna A. alexandri C. costae Weight (gm) N 1 1 24 17 25 X S.D. 7.5 3.52 4.27 ±0.42 3.56 ±0.31 3.25 ±0.26 Wing chord (mm) N 1^ 1 16 17 25 X S.D. 80.0 58.0 49.78 ±1.56 46.17 ±0.92 44.72 ±0.88 Exposed culmen (mm) N 1 1 20 16 25 X S.D. 26.3 20.2 18.23 ±0.74 20.46 ±0.69 17.56 ±0.62 Tail length (mm) N 0 1 25 25 25 X S.D. 30.0 25.42’ ±0.94 26.53’ ±0.87 23.30 ±1.00 ^Stiles 1971 ^Study skin, WFVZ 26 alexandri BLUE-THROATED HUMMINGBIRD HYBRIDIZATION o ix> ra c c. to o! L /2 Ln o s- •o c ra X OJ rc CM CM o CM in (A "C 0) a (A "(3 c 0) ha <0 a _Q) Ta lA O a 1^ 'O' |X to E rc S- cn 0 o CM un 1/1 s- cu +J O) E lA _Q) 10 E 0) <4— O TJ C IC 00 C^ o "O' o cn LD 0) x> o -*-* u O CM V t /1 o u |X |X © m CO |X _ IX - c 0) J J o n CO CM :3 U T 3 W (A O a X UJ O) ra +J t/i o u Ol rc c c rC O CO Ln O r"N CM LO 1 T c ra cu II c_ o •r- ra •r— > CD T3 "D lx S- ra II II T3 c c ra ra O) cu o c (U T3 O 27 JZ •iha O c cu E 3 U T 3 CU CA o a X cu JZ O) ■qS o c o (A ‘C (O a E o U CO (U ha 3 CO BLUE-THROATED HUMMINGBIRD HYBRIDIZATION DISCUSSION Of the three types of information— color, known distribution, and breeding phenology— available to us for determining the identity of male parents in- volved in the nesting attempts, color is useful only in eliminating the genera Selasphorus and Stellula from consideration. Usual distribution patterns prob- ably eliminate another species, Costa’s Hummingbird, although the possibility of a vagrant male Costa’s occurring in the area cannot be totally discounted. Of the two remaining species, one, Anna’s Hummingbird, was common and breeding in the study area during the first nesting attempt, and for this reason it is the most likely male parent for the first nesting, the light weight of the hybrids notwithstanding. Similarly, the most abundant hummingbird locally at the beginning of the second nesting attempt was the Black-chinned Hummingbird, and individuals of this species were actually seen displaying to the female blue-throat. We suggest that this species is a likely candidate for the second parent along with Anna’s Hummingbird, which presumably was reproductively active throughout the spring. Banks and Johnson (1961) noted that “once a specimen is determined to be a natural hybrid, assumptions as to the natural parentage of such a bird are only ‘best guesses’ and cannot, except in rare instances, be established with certainty.” Despite the fact that in the present instance one parent involved in the hybridizations is known with certainty, the identity of its hybrid mates must still remain a matter of the “best guess.” SUMMARY A female Blue-throated Hummingbird, the first recorded in California, was discovered in Three Rivers, Tulare County, in late December 1977. The bird remained in the vicinity until late May 1978. During its stay it nested twice. Two young were successfully produced from the first nesting attempt, but the second attempt failed in the early nestling stage. Because of the apparent lack of a conspecific male and the appearance of the young from the first nesting attempt, we believe these attempts were hybridizations. Although the male parents involved could not be identified unequivocally, we suggest that Anna’s Hummingbird was the most likely parent in the first nesting and that either an Anna’s or Black-chinned Hummingbird was the male parent in the second attempt. ACKNOWLEDGMENTS We are most grateful to Mr. and Mrs. Ted Price and Gertrude Schuckert of Three Rivers for providing access to their properties for study purposes. John Lindsay, Keith Hansen and Mark Myers provided valuable field assistance, 28 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION and Roger Cobb and Michael Morrison assisted in various ways at the Western Foundation of Vertebrate Zoology. R.S. “Bud” Kilburn and Ray Quigley pro- vided their photographic equipment and expertise. Laurence Binford, Thomas Howell, J.V. Remsen, Jr., and Stephen Russell gave us access to specimens in their care. We thank Eric Johnson for reviewing an early draft and especially F. Gary Stiles for his generous assistance on the final draft. This study was supported in part by Ed Harrison and the Western Foundation of Vertebrate Zoology. LITERATURE CITED American Ornithologists’ Union, 1957. Check-list of North American birds. 5th ed. Am. Ornithol. Union, Baltimore, MD. Baldridge, F.A. 1983. Plumage characteristics of juvenile Black-chinned Humming- birds (Archilochus alexandri). Condor 85:102-103. Banks, R.C. & N.K. Johnson. 1961. A review of North American hybrid humming- birds. Condor 63:3-28. Grinnell, J. & A.H. Miller. 1944. The distribution of the birds of California. Pac. Coast Avif. 27. Hubbard, J.P. 1978. Revised check-list of the birds of New Mexico. New Mexico Or- nithol. Soc. Publ. No. 5. Luther, J.S., G. McCaskie & J. Dunn. 1979. Third report of the California Bird Rec- ords Committee. West. Birds 10:169-187. Lynch, J.F. &P.L. Ames. 1970. A new hybrid hummingbird, Archilochus alexandri x Selasphorus sasin. Condor 72:209-212. Marshall, J.T., Jr. 1957. Birdsofthepine-oak woodland in southern Arizona and adja- cent Mexico. Pac. Coast Avif. 32. Mayr, E. & L.L. Short, Jr. 1970. Species taxa of North American birds, a contribution to comparative systematics. Publ. Nuttall Ornithol. Club No. 9. Oberholser, H.C. 1974. The birdlife of Texas. Vol. 1. Univ. Texas Press, Austin. Ortiz-Crespo, F.I. 1972. A new method to separate immature and adult hummingbirds. Auk 89:851-857. Phillips, A.R. 1975, Migration of Allen’s and other hummingbirds. Condor 77: 196-205. Phillips, A.R., J. Marshall & G. Monson. 1964. The birds of Arizona. Univ. Arizona Press, Tucson. Short, L.L., Jr., & A.R. Phillips. 1966. More hybrid hummingbirds from the United States. Auk 83:253-265. Skutch, A.F. 1962. The constancy of incubation. Wilson Bull. 74:115-152. Stiles, F.G. 1971. On the field identification of California hummingbirds. Calif. Birds 2:41-54. Stiles, F.G. 1973. Food supply and the annual cycle of the Anna’s Hummingbird. Univ. California Publ. Zool. 97:1-116. Stiles, F.G. &L.L. Wolf. 1973. Techniquesfor color-marking hummingbirds. Condor 75:244-245. Van Tyne, J. 1953. Geographic variation in Blue-throated Hummingbirds (Lampornis clemenciae) . Auk 70:207-209. Wagner, H O. 1946. Food and feeding habits of Mexican hummingbirds, Wilson Bull. 58:69-93. 29 BLUE-THROATED HUMMINGBIRD HYBRIDIZATION Wagner, H.O. 1952. Beitrag zur Biologic des Blaukehkoiibris Lampornis clemenciae (Lesson). Veroff, Mus. Bremen, Reihe A, Bd. 2:5-44. Wells, S. , R.A. Bradley & L.F. Baptista. 1978. Hybridization in Cali/pte hummingbirds. Auk 95; 537-549. Williamson, F.S.L. 1956. The molt and testis cycle of the Anna Hummingbird. Condor 58: 342-366. Accepted 10 May 1982 Blue-throated Hummingbird 30 Sketch by Keith Hansen FORAGING ECOLOGY OF THE RED-FACED WARBLER DURING THE BREEDING SEASON KATHLEEN E. FRANZREB, Endangered Species Office, U.S. Fish and Wildlife Ser- vice, 1230 N Street, Sacramento, California 95814 BARBARA J. FRANZREB, 4 Surrey Lane, Rancho Palos Verdes, California 90274 The Red-faced Warbler {Cardellina rubrifrons) is primarily a Mexican species which breeds from central Arizona and southwestern New Mexico south through the mountains of northwestern Mexico. During the breeding season it inhabits montane forests; nests are constructed on the ground and are well concealed by vegetation. Although not shy, this species is relatively quiet and inconspicuous in spite of its striking coloration, and little is known about its ecology. In 1973 and 1974 we studied the Red-faced Warbler to analyze quan- titatively its foraging behavior during the nesting season. Such information should add to our understanding of the ecology of this little-studied species. STUDY AREA AND METHODS The Willow Creek watershed is located approximately 80 km south of Springerville in the Apache-Sitgreaves National Forest, Greenlee County, White Mountains, Arizona. Elevation ranges from 2682-2805 m. The water- shed is covered by a mixed-coniferous forest composed predominantly of Douglas-fir, Ponderosa Pine and Southwestern White Pine. We established a 15.5 ha study plot using a system of 9 parallel, flagged transect lines 390 m in length and 50 m apart. Vegetation Analysis We sampled the vegetation using the plotless point-quarter method (Cot- tam and Curtis 1956); 400 mature trees (diameter at breast height greater than or equal to 7.6 cm) were measured. Dominance values were based on basal area estimations. We estimated the height of each tree using a clinometer. Results were segregated into 3 m height intervals and provided frequency data for each height class. Additional details of the methods used in the vegetation analysis are available in Franzreb (1978). Foraging Behavior We obtained foraging data on Red-faced Warblers from mid-May through Augustin 1973 and 1974 by systematically traversing transect lines. Observa- tions were taken under skies that were generally clear to less than 30% over- Western Birds 14: 31-38, 1983 31 RED-FACED WARBLER FORAGING ECOLOGY cast; wind conditions varied from no wind to light wind (Beaufort scale 0 to 2) . Although we collected data throughout the day, the majority of observations were made during morning hours (0600-1000). We collected foraging data for eight niche dimensions: method of prey pro- curement, stance, perch type, perch diameter, distance from the branch tip to the perch site, tree species preferences, tree height, and bird location in the tree relative to the ground. One observation per bird per sighting was taken to reduce sampling bias. Method of foraging referred to the manner in which food was collected. Categories included glean, hover, hawk (sallying from a branch to catch flying insects) , and peck-probe. Stance employed while foraging was either standing upright, hanging upside down, or clinging in a sideways position. Birds observed on the trunk were recorded as being in the sideways position. We denoted the kind of material on which the bird perched as perch type. We further categorized each observation in the branch and twig perch class on the basis of perch diameter. The bird’s position relative to the branch tip was categorized by subdividing the branch into thirds. The height and species of tree and the bird’s distance from the ground were recorded for each observa- tion. Table 1. Vegetation analysis of mixed-coniferous forest, White Mountains, Arizona. Species Density ^/ha Ponderosa Pine (Pinus ponderosa) 112.7 Southwestern White Pine (Pinus strobiformis) 109.6 Douglas-fir (Pseudotsuga menziesii) 194.1 Alpine Fir (Abies lasiocarpa) 3.1 White Fir (Abies concolor) 51.7 Blue Spruce (Picea pungens) 12.5 Engelmann Spruce (Picea engelmanni) 31.3 Quaking Aspen (Populus tremuloides) 50.1 Snag (dead tree) 61.1 Total 626.2 Relative density Relative dominance Relative frequency 18.0 30.5 19.3 17.5 10.6 18.6 31.0 35.2 26.1 0.5 0.3 0.7 8.3 7.6 8.6 2.0 0.7 2.5 5.0 2.7 5.4 8.0 4.1 8.2 9.8 8.3 10.7 100.0% 100.0% 100.0% 1 Total density of all species = unit area/(mean plant-to-point distance)^. 32 RED-FACED WARBLER FORAGING ECOLOGY Foraging behavior diversity was calculated using Shannon’s (1948) for- mula. Evenness (Pielou 1975} values were then calculated (J ' = H ' and indicated the degree of foraging specialization for each dimension. Even- ness values range from 0 to 1, with values approaching 1 indicating more even utilization of available resource categories, hence, a species that is more of a generalist with regard to that particular foraging trait. RESULTS Vegetation Douglas-fir was the dominant tree comprising the highest density (194.4 trees/ha) and being the most common (Table 1). In this mixed-coniferous forest Ponderosa Pine and Southwestern White Pine were also substantial components of the vegetative community. Total tree density was estimated at 626.2 tree/ha. Trees 9 m or less in height constituted 46.2% of the total tree composition (Table 6). The tallest trees on the watershed (e.g., greater than 27 m) oc- curred with only a 6.3% frequency. Additional details of the vegetation analysis may be found in Franzreb (1978) and Franzreb and Ohmart (1978) . Foraging Behavior Gleaning was the predominant foraging method (89.4%) (Table 2). Vir- tually all foraging (130 observations) occurred on branches/twigs (99.2%) rather than on trunks (0.8%), leaves (0%), or cones (0%). Over 75% of the branches selected were 1.3 cm or less in diameter (Table 3) . Warblers tended to use the third of the branch closest to the tip more often than either the mid- dle portion or that closest to the trunk (Table 4) . Red-faced Warblers foraged most frequently in Douglas-fir (40.8% of observations) and Southwestern White Pine (26.1%) (Table 5). Considering the number and size of Ponderosa Pines, they were little used (8.4%). Table 2. Method of foraging of Red-faced Warblers during the breeding season. Method Number and Percent of Observations Glean 126 89.4% Hover 12 8.5% Hawk 3 2.1% Total 141 100.0% Table 3. Diameter of perch utilized by foraging Red-faced Warblers. Perch Diameter Number and Percent of Observations >5.1 cm 5 4.7% > 2.5 < 5.1 cm 6 5.6% > 1.3 < 2.5 cm 13 12.1% < 1.3 cm 83 77.6% Total 107 100.0% 33 RED-FACED WARBLER FORAGING ECOLOGY Table 4. The portion of the branch used by Table 7. Distance from ground of Red- Red-faced Warblers while foraging. faced Warbler foraging sites. Distance From Number and Percent Height from Number and Percent Branch Tip of Observations Ground of Observations 0-33% 51 39.2% < 9 m 74 55.6% > 33 - 66% 43 33.1% >9< 18 m 55 41.4% >66% 36 27.7% > 18 < 27 m 4 3.0% > 27 < 36 m 0 0 Total 130 100.0% > 36 m 0 ' 0 Total 133 100.0% Table 5. Tree species selected by foraging Red-faced Warblers. Table 8. Diversity (H') and evenness (J') Number and Percent values for foraqlnq characteristics of Red- Species of Observations faced Warblers. Ponderosa Pine 12 8.4% Foraging Category Diversity Evenness Southwestern 37 26.1% White Pine Method 0.39 0.36 Douglas-fir 58 40.8% Stance 0 0 Alpine Fir 2 1.4% Perch type 0.05 0.07 White Fir 4 2.8% Perch diameter 0.76 0.55 Blue Spruce 5 3.5% Distance from tip 1.09 0.99 Englemann 13 9.2% Tree species 1.66 0.76 Spruce Tree height 1.45 0.90 Quaking Aspen 9 6.4% Distance from 0.80 0.50 Snag 2 1.4% ground Total 142 100.0% Mean evenness 0.52 Table 6. Tree height selection by foraging Red-faced Warblers and tree height frequency. Tree Height Number and Percent of Observations Tree Height Frequency’ < 9 m 22 15.6% 46.2% >9< 18 m 50 35.4% 29.8% > 18 < 27 m 42 29.8% 17.7% > 27 < 36 m 19 13,5% 5.0% > 36 m 8 5.7% 1.3% Total 141 100.0% 100.0% ’Based on measurements obtained during vegetation analysis. 34 RED-FACED WARBLER FORAGING ECOLOGY Most foraging occurred in the medium to tall trees— those greater than 9 m but less than or equal to 27 m (Table 6) . The shortest trees (9 m or less) were used considerably less frequently than the proportion they comprised of the vegetation profile. The Red-faced Warbler frequently foraged relatively close to the ground (Table 7). In fact over 55% of the observations occurred within 9 m of the forest floor. An estimated 97% of foraging activities were conducted in trees within 18 m from the ground, even though substantial foliage volume was available higher in the trees. Distance from the tip was the most generalized foraging characteristic as in- dicated by the evenness value (0.99) (Table 8) . Tree height selection was also relatively generalized. In contrast, stance was a highly specialized foraging category showing no diversity. Perch type was also highly stereotyped. DISCUSSION Warbler foraging ecology has been the subject of a number of studies (MacArthur 1958; Morse 1967a, b, 1968, 1971, 1976; Wilz and Giampa 1978; Szaro and Baida 1980; Hutto 1981). However, none of these studies examined foraging ecology of the Red-faced Warbler, a primarily Mexican species whose breeding range northernmost extension is central Arizona and southwestern New Mexico. Red-faced Warblers preferred to forage in Douglas-fir, the dominant tree species. Disproportionately more observations occurred in this tree species even considering its dominance and relatively high foliage volume (17.6% of all foliage) (Franzreb 1978) in the habitat. Szaro and Baida (1980) noted that Red-faced Warblers were not present below a certain foliage volume. In this study they tended to utilize the tree species with the densest foliage. Thus, they were less frequent in Ponderosa Pine than expected on the basis of plant density and relative frequency data. Their increased use of Southwestern White Pine may perhaps be attributed to the fact that this tree’s foliage density is generally higher than that of Ponderosa Pine. Foliage density may be impor- tant because of its influence on food availability, quantity and distribution. The degree to which a particular tree species is capable of providing suitable cover (necessary for protection against predators and inclement weather) is partly dependent on the density of foliage. Red-faced Warblers selected moderate (>9 m) , moderately tall (< 27 m) , and tall (> 27 m) trees for foraging considerably more often than anticipated based on the proportion of trees of these heights in the habitat. However, their use of these trees was not as pronounced as that of other species on the study plot such as Mountain Chickadee (Parus gambeli) and Ruby-crowned Kinglet [Regulus calendula). Red-faced Warblers showed a decided preference to forage relatively close to the ground (i.e. , within 9 m) . Again, this is quite different from the behavior 35 RED-FACED WARBLER FORAGING ECOLOGY of the most common species on the study area: Mountain Chickadee, Ruby- crowned Kinglet and Yellow-rumped Warbler {Dendroica coronata) . Studies examining niche overlap between subordinate and dominant species have usually found a decrease in niche breadth in the subordinate species when in the presence of a dominant (Colwell and Futuyma 1971, Morse 1974). However, other workers have noted an increase in niche breadth along certain niche dimensions when dominants were present (Willis 1966, Morse 1970, Yeaton 1974). In this study, it may well be that inter- specific competition resulted in the restriction of the Red-faced Warbler to the lowest areas of the vegetation profile. The Red-faced Warbler was present in relatively low density when com- pared to other species such as the Yellow-rumped Warbler, possibly its closest potential competitor because of morphological similarities. Red -faced Warbler densities were 10.6 birds/40 ha in 1973 and 25.6/40 ha in 1974 compared to 131.6/40 ha and 89.8/40 ha for the Yellow-rumped Warbler (Franzreb and Ohmart 1978). Mountain Chickadees and Ruby-crowned Kinglets were also considerably more numerous than Red-faced Warblers (Franzreb and Ohmart 1978). In a Maine spruce fir forest, Morse (1967a) found that kinglets and other warblers were an important factor limiting the distribution of the Northern Parula (Parula americana) . A similar situation may be occurring in this study area. It also was noted, in an investigation of four species of Dendroica warblers, that males tended to forage closer to their song posts than to their nests, whereas females tended to forage closer to the nests than to the male song perches (Morse 1968). This behavior presumably results in partitioning the habitat to provide for the most efficient resource exploitation. Because the Red-faced Warbler is a ground nester, it would be reasonable to predict that it would forage closer to the ground than tree-nesting species, especially once eggs hatch and the substantial food requirements of nestlings place an addi- tional burden on the adults. The most specialized foraging categories (method, stance and perch type) as indicated by diversity and evenness values were the most constrained by morphological considerations. The other characteristics were less stereotyped and behaviorally more plastic. SUMMARY We examined the foraging ecology of the Red-faced Warbler in a mixed- coniferous forest, White Mountains, Arizona, during the breeding season in 1973 and 1974. Foraging characteristics addressed included method, stance, type of perch, diameter of perch, position on the branch, tree species selec- tion, tree height preferences, and height from the ground. Diversity (H ') and evenness (J ') values indicated that this warbler was most diverse in distance from the branch tip and in tree height selection. Red-faced Warblers over- 36 RED-FACED WARBLER FORAGING ECOLOGY whelmingly preferred to glean on branches/twigs and usually selected the smallest (< 1.3 cm) branches with a slight preference for the third of the branch closest to the tip. Over 66% of the observations occurred within Douglas-fir and Southwestern White Pine. Although trees of all heights were utilized, warblers preferred to forage relatively close to the ground. This preference may have resulted from interspecific competitive pressures, or possibly, because this species is a ground nester, foraging closer to the ground may be energetically more efficient. ACKNOWLEDGMENTS This study was supported by Cooperative Aid Agreements (Nos. 16-382-CA and 16-402-CA during 1973 and 1974, respectively) from the U.S. Forest Service, Rocky Mountain Forest and Range Experiment Station, Tempe, Arizona. LITERATURE CITED Colwell, R.K & D.J. Futuyma. 1971. On the measurement of niche breadth and over- lap. Ecology 52:567-576. Cottam, G. & J. Curtis. 1956. The use of distance measures in phytosociological sam- pling. Ecology 37:451-460. Franzreb, K.E. 1978. Tree species used by birds in logged and unlogged mixed-conif- erous forest. Wilson Bull. 90:221-238. Franzreb, K.E. & R.D. Ohmart. 1978. The effects of timber harvesting on breeding birds in a mixed-coniferous forest. Condor 80:431-441. Hutto, R.L. 1981 . Seasonal variation in the foraging behavior of some migratory west- ern wood warblers. Auk 98:765-777. MacArthur, R.H. 1958. Population ecology of some warblers of northeastern conifer- ous forests. Ecology 39:599-619. Morse, D.H. 1967a. Competitive relationships between Parula Warblers and other species during the breeding season. Auk 84:490-502. Morse, D.H. 1967b. Foraging relationships of Brown-headed Nuthatches and Pine Warblers. Ecology 48:94-103. Morse, D.H. 1968. A quantitative study of foraging of male and female spruce-woods warblers. Ecology 49:779-784. Morse, D.H. 1970. Ecological aspects of some mixed species foraging flocks of birds. Ecol. Monogr. 40:119-168. Morse, D.H. 1971. The insectivorous bird as an adaptive strategy. Ann. Rev. Ecol. Syst. 2:177-200. Morse, D.H. 1974. Niche breadth as a function of social dominance. Amer. Nat. 108' 818-830. Morse, D.H. 1976. Variables affecting the density and territorial size of breeding spruce- woods warblers. Ecology 57:290-301. Pielou, E.C. 1975. Ecological diversity. John Wiley & Sons, New York. Shannon, C.E. 1948. The mathematical theory of communication. Bell Syst. Tech J 27:379-423; 623-656. Szaro, R.C. & R.P. Baida. 1980. Bird community dynamics in a Ponderosa Pine for- est. Studies in Avian Biol. No. 3. 37 RED-FACED WARBLER FORAGING ECOLOGY Willis, E.O, 1966. Interspecific competition and the foraging behavior of Plain-brown Woodcreepers. Ecology 47:667-672. Wilz, K.J, & V. Giampa. 1978. Habitat use by Yellow-rumped Warblers at the north- ern extremities of their winter range. Wilson Bull. 90:566-574. Yeaton, R.l. 1974. An ecological analysis of chaparral and pine forest bird communi- ties on Santa Cruz Island and mainland California. Ecology 55:959-973. Accepted 4 Februarii 1 983 Red-faced Warbler Sketch by Narca Moore 38 FIRST NESTS OF HEERMANN’S GULL IN THE UNITED STATES JUDD HOWELL, DAVID LACLERGUE, SHARON PARIS, and WILLIAM I. BOAR- MAN, National Park Service, Golden Gate National Recreation Area, Fort Mason, Building 201, San Francisco, California 94123 ANTHONY R. DEGANGE, U.S. Fish and Wildlife Service, 1011 E. Tudor Road, An- chorage, Alaska 97503 LAURENCE C. BINFORD, 985 Emily Avenue, Rohnert Park, California 94928 The primary breeding colonies of Heermann’s Gull (Larus heermanni) are on islands in the Gulf of California, Mexico. Only two colonies are known from the Pacific side of the Baja California peninsula. One was on Isla San Roque (27°09 'N; Grinnell 1928), where Huey (1927) found 35 pairs begin- ning to lay on 20 April 1927. The second colony, previously the northwesternmost for the species, was discovered on Isla Benito del Centro of the San Benito Islands (28°20 'N) on 25 May 1971, when Jehl (1976) found 25 adults and nine nests containing one to five eggs each. Later surveys disclosed 15 adults and two active nests with one small chick each on 21 June 1974 (Jehl 1976) and at least 30 adults, eight scrapes and eight nests contain- ing eggs and/or small chicks on 9 June 1975 (Boswall 1978). In this paper we describe the first nesting attempts by Heermann’s Gull in the United States. The species nested at two locations in California; on Alcatraz Island in 1979, 1980 and 1981, and at Shell Beach in 1980. Brief ac- counts were published by Binford (1980) and by Laymon and Shuford (1980) for Alcatraz and by Sowls et al. (1980) for Shell Beach. ALCATRAZ ISLAND Alcatraz Island (37°49 'N) is part of the Golden Gate National Recreation Area (GGNRA) and is located in San Francisco Bay, San Francisco County, about 1 .6 km north of the city of San Francisco and 1250 km north of the San Benito Islands. Formerly used as a penitentiary, it is now staffed throughout the year by personnel of the Golden Gate National Recreation Area, who con- duct tours for the public. The 4.8 ha island forms a 540 m long rough oval running northwest-south- east. The nests were located on the southwest side of the northwest half, just south of the industrial shop, about 3 m from a 1.8 m-tall incinerator, and about 13 m above and about 5 m away from the edge of San Francisco Bay (Figure 1) . They were situated under the canopy on the north side of a Coyote Bush [Baccharis pilularis var. consanguinea) which measured 1.68 m tall and 2.74 m in diameter. Summer 1979. In summer, 1979, Bob Connell (pers. comm.), a security guard on Alcatraz, saw two adult Heermann’s Gulls and a nest containing Western Birds 14: 39-46, 1983 39 HEERMANN’S GULL NESTS three eggs under the Coyote Bush but did not report his discovery. He saw no chicks but noted that only one egg remained after the season. As confirmation of this nesting, on 17 June 1980 Binford and Howell found an old scrape 30 cm from the edge of the 1980 nest. The two immature Heermann’s seen by Laclergue at the site in early summer 1980 might have been from the 1979 nesting (but see Discussion) . Summer 1980. In 1980 summering Heermann’s Gulls were first detected on 15 June by Paris. She and Laclergue notified Howell, who visited the site the next day and discovered one adult on a nest containing three eggs. On 17 June, Binford and Howell found two adult Heermann’s Gulls, one sitting on the nest and the other standing on the incinerator about 3 m away. As the observers approached cautiously, the incubating bird walked off the nest. Twice the observers stopped, and twice the bird returned to the nest; this behavior suggested close nest attentiveness. The three warm eggs (Figure 2) compared favorably with specimens borrowed from the California Academy of Sciences. A fourth egg, cold and abandoned, lay 75 cm from the center of the nest. Binford collected and prepared this egg (CAS egg collection 9501). It was uncracked and apparently fresh; a sticky substance and several feathers adhering to the surface washed off with difficulty. The egg measured 59.75 x 44.21 mm and in color and pattern was typical of Heermann’s Gull eggs. For the next 6 weeks Binford, Howell, Laclergue and Paris checked the nest intermittently. On 23 June Binford and Howell found one adult incubat- ing and a second roosting with Western Gulls (Larus occidentalis) some dis- tance away. The incubating bird hovered in the vicinity as the observers ap- proached but then disappeared. Howell collected one of the three eggs on 8 July (specimen in GGNRA collection); it lay near the nest, broken longitudi- nally and empty. On 22, 23, and 24 July the adults were still incubating the re- maining two eggs. The next day the adults perched on the incinerator but were not seen on the nest. Neither adult was present on 26 July. Both eggs were in the nest on 28 July but one was cold and the other (collected, GGNRA) was cracked longitudinally. The nest was last checked on 4 August, when Howell found the conical tip of the last egg, broken and empty, 75 cm from the nest. The nest consisted of a ring-shaped mound of debris and soft dry earth (Figure 2) . The former included numerous twigs 2-5 cm long, about five white breast feathers probably from Western Gulls, several small bones, four bits of cigarette package tinfoil, a piece of weathered rag, and many pieces of dried leaves of the Coyote Bush, The nest was unlined. The dimensions of the nest ring were as follows: outer diameter, 360 mm; inner diameter, 190 mm; width, 85 mm; depth at center of nest (to top of ring), 40 mm. In the mornings the nest was shaded from direct sunlight by the higher parts of the island, and in the afternoon it received about 50% sunlight through the bush canopy. The nearest nest of the Western Gull, which breeds commonly on the island, was 23 m northeast of the Heermann’s nest and contained one egg. Spring-Summer 1981. On 27 January 1981 Howell began observing ac- tivities in the vicinity of the 1980 Alcatraz nest. The following is a synopsis of his observations for the 24 days he visited the area. 27 Januari/: three adults and three immatures present. 1 7 February;: one adult and two immatures present; no evidence of nesting under Baccharis bush. 18 March: one adult, 40 Figure 1. Incinerator compound on Alcatraz Island, looking southwest toward San Francisco, California, 23 June 1980. Heermann's Gull nest was under canopy of Coyote Bush indicated by arrow in lower center of photo . Photo by Judd A. Howell 41 HEERMANN’S GULL NESTS two immatures. 31 March: two adults. 6-28 April: two-three adults and one- two immatures; no scrape found. 4 May: two adults, one of which walked under Coyote Bush (no eggs seen). 6 May.' two adults under Coyote Bush, one sitting next to 1980 nest scrape, other at edge of bush; two eggs in scrape near 1980 nest; tours rerouted to avoid incinerator area, even though they seemed not to disturb nesting birds. 13 Mai;: parents twice exchanged places on nest; parent standing near bush called and lunged at a Western Gull that walked past, causing it to fly; non-incubating adult placed one twig next to in- cubating bird; latter bird later gathered nest material within reach and placed it onto nest ring. 19 Mai/: Connell noted four eggs in the nest; Howell saw one adult on nest. 27 Mai>-15 June: two adults present; incubating adults added feathers to nest; parents exchanged incubation duties; still four eggs in nest; accumulation of feathers indicated one bird molting primaries and body feathers (Figure 3). 15-18 June: Third adult (migrant?) noted in area. 23 June: adult left nest upon being approached; 30 nonbreeding (migrant) Heer- mann’s Gulls flew by; Howell collected one cracked egg out of the nest, and took following notes: outer diameter of nest ring, 380 x 330 mm; depth of cup, about 40 mm; nest composed of leaves, sticks, feathers, and bits of glass; intact egg collected measured 42 x 57 mm; partly decomposed contents of intact egg indicated infertility or early arrested development. 1 Ju/y; one adult standing outside nesting area; one other flying and calling some distance away; both eggs cracked, one 15 cm and the other 150 cm away from nest; numerous Heermann’s Gulls at edge of bay. Figure 2. Heermann’s Gull nest with three eggs, 23 June 1980, Alcatraz Island, Califor- nia . Photo by Judd A . Howell 42 HEERMANN’S GULL NESTS SHELL BEACH The town of Shell Beach (35°09'N) is located on the coast of San Luis Obispo County just northwest of Pismo Beach and about 900 km (569 mi) northwest of the San Benito Islands. Just offshore from town are numerous rocks, some of which support breeding American Black Oystercatchers {Haematopus bachmani), Western Gulls and Pigeon Guillemots (Cepphus columba) . On 26 May 1980, while conducting hourly counts on seabirds, DeGange discovered two nests of Heermann’s Gull on one of these rocks (Figure 4) . The nest rock, 80 m from shore and 350 m SE of South Point (U.S. Geological Survey, Pismo Beach, California, Quadrangle), rises about 6.5 m above the high tide mark and is about 5.3 m in diameter at mid- height. The north nest was situated near the top, while the south nest was about 0.5 m lower. Both nests were near the east end of the rock. Because none of the observers could land on the rock, the details of nest site, construction, and ex- act contents could not be ascertained; all observations were made from the mainland 112 m away. On the day of his first visit, DeGange noted five breeding-plumaged Heer- mann’s Gulls, two of which were sitting on the nests. Some of the other Heer- mann’s occasionally chased Western Gulls and Rock Doves (Columba livia). At nightfall, the two sitting Heermann’s and one additional adult were still present. Figure 3. Pair of adult Heermann’s Gulls at nest site, 4 June 1981, Alcatraz Island, California. Parent on the left is incubating. Photo by Judd A. Howell 43 HEERMANN’S GULL NESTS On 27 May DeGange returned with Margaret Stewart. With the aid of a spotting scope they were able to see some nest vegetation under the two sitting birds. The nests were about 2 m apart and about 5 m from a Western Gull nest on which a bird was incubating. The north Heermann’s nest contained at least one egg; the south nest was hidden by the terrain, but was assumed to contain eggs judging from the behavior of the parents. At no time did DeGange note any aggression between the two nesting pairs of Heermann’s. The following is a summary of DeGange’s field notes written from 0830 to 0940 on 27 May. 0830: two adult Heermann’s Gulls, in addition to the in- cubating birds, standing on rock when observers arrived. 0845: two standing birds chased another adult Heermann’s off rock and returned; bird sitting on north nest stood up, stared down into nest, and resettled; one standing Heer- mann’s chased an American Black Oystercatcher off rock. 0900: bird sitting on south nest exchanged places with one of two standing birds; the replaced bird picked up and dropped several pieces of vegetation. 0910: two other adult Heermann’s flew in; one walked over to Western Gull nest, stood over incubating bird, and made a series of head up vocalizations; breeding Heer- mann’s chased away the other intruder Heermann’s. 0915: one of standing adults exchanged places with bird sitting on north nest; latter bird picked up three small pieces of vegetation near nest but each time dropped it and chased one of the intruder Heermann’s; same parent later chased Rock Dove away from vicinity of nest and at 0935 took some nest material to north nest. Arthur L. Sowls (pers. comm.), U.S. Fish and Wildlife Service, made the following observations. In the evening of 10 June, three Heermann’s Gulls were on the rock, two on the nests. The next morning one bird was on the north nest, and occasionally a second bird would arrive on the rock. The Western Gull nest contained at least two small chicks. Don Parham (pers. comm.) of the Morro Bay Audubon Society visited the site one day in June and saw no sign of nesting Heermann’s Gulls. DeGange returned on 16 July and found no nesting Heermann’s Gulls; he saw many migrant Heermann’s in the course of an all-day count. DISCUSSION The bulk of evidence indicates that all three nesting attempts on Alcatraz were unsuccessful. It is tempting to speculate that the full-sized immatures that frequented the site in 1980 and 1981 came from the nests, but more likely they were simply Baja birds that migrated north the previous summer and were induced to overwinter by the presence of adults. We doubt that climate caused the nest failures. Alcatraz does have a much colder climate than do the islands of Baja, San Francisco having lower average air temperatures, more frequently overcast skies (high fog) , and cold- er winds. Further, these conditions probably were accentuated by the position of the nests, which were exposed to the prevailing cold west winds, shaded by the island in the mornings, and partially shaded by the bush in the afternoons. Nevertheless, the parents incubated the eggs continuously during periods of observation, and it seems likely that their attentiveness was adequate to shield the eggs from the environment. 44 HEERMANN’S GULL NESTS That disturbance from tour groups passing 36 m away could have con- tributed to the failure of the Alcatraz nests seems unlikely. On numerous occa- sions in 1981 Howell noted that passing tours, as well as low-flying aircraft, failed to dislocate the incubating parent or cause more than momentary reac- tion on the part of the nonincubating adult. When the parent was dislocated it returned to the nest in a matter of minutes. Also, the tours were rerouted to avoid the nesting area on 6 May 1981, before the last two eggs were laid. Neither did the presence of the researchers seem to greatly disturb the birds. While the abandoned egg found on Alcatraz on 17 June 1980 might have owed its undeveloped embryo to lack of incubation, such could not have been the case for the intact egg removed from the nest on 23 June 1981, which had been incubated for over 5 weeks and was shown to be undeveloped. Thus the evidence suggests that infertility was the most likely cause of the Alcatraz nest failures. The fate of the two Shell Beach nests is unknown, although Sowls et al. (1980) probably were correct in stating that the attempts were unsuccessful. It should be noted, however, that the 5 weeks between 10 June, when Sowls saw adults on both nests, and 16 July, when DeGange made the next exten- sive observations, might have been enough time for the eggs to hatch and the young to mature to flying stage. Figure 4. Two Heermann’s Gull nests on sea stack, 27 May 1980, Shell Beach, Califor- nia. Arrows indicate nest location with parents. Photo by A. R. DeGange 45 HEERMANN’S GULL NESTS Heerman’s Gull is rare in California during the spring when the species is breeding farther south (McCaskie et al. 1979). The first northward movements into the southern and central parts of the state normally take place in early to mid-July. In some years, however, appreciable numbers arrive in early June, as was the case at Pacific Grove, Monterey County, in 1971, when 46 birds were seen on 10 June (DeSante and LeValley 1971), and in 1973, when 100 -I- were present on 4 June (Remsen and Gaines 1973). The California birds begin egg laying by early May, well before the earliest influxes of birds from the south. Hence chronological as well as biological factors argue against the California breeding birds’ being migrants from the south. Jehl (1976) pointed out that Heermann’s Gulls on the San Benitos nest a month or two later than the populations in the Gulf of California and sug- gested that the environmental conditions required for successful breeding may not be achieved along the outer coast until late spring and early summer. The same may be said for the Shell Beach and Alcatraz birds, which have breeding seasons similar to those on Isla San Roque and the San Benitos. ACKNOWLEDGMENTS We thank Joseph R. Jehl, Jr., of the Hubbs-Sea World Research Institute for supplying important references and Dennis E. Breedlove of the California Academy of Sciences for identifying the Coyote Bush. The National Park Ser- vice provided funds for the publication of the color plates. LITERATURE CITED Binford, L.C. 1980. Heermann’s Gull invades Alcatraz. Point Reyes Bird Observatory Newsl. 51:3. Boswall, J. 1978. The birds of the San Benito Islands, Lower California, Mexico. Bris- tol Ornithology 11:23-32. DeSante, D. & R. LeValley. 1971. The nesting season. Middle Pacific coast region. Am. Birds 25:899-904. Grinnell, J. 1928. A distributional summation of the ornithology of Lower California. Univ. California Publ. Zool. 32:1-300. Huey, L.M. 1927. Northernmost breeding station of the Heermann Gull on the Pacific Ocean, and other notes from San Roque Island, Lower California. Condor 29:205-206. Jehl, J.R., Jr. 1976. The northwestern most colony of Heermann’s Gull. West. Birds 7:25-26. Laymon, S.A. & W.D. Shuford. 1980. The nesting season. Middle Pacific coast re- gion. -Am. Birds 34:925-929. McCaskie, G., P. DeBenedictis, R. Erickson &J. Morlan. 1979. Birds of northern Cali- fornia, an annotated field list. 2nd ed. Golden Gate Audubon Society, Berkeley, CA. 84 pp. Remsen, V. & D.A. Gaines. 1973. The nesting season. Middle Pacific coast region. Am. Birds 27:911-917. Sowls, A.L., A.R. DeGange, J.W. Nelson & G.S. Lester. 1980. Catalog of California seabird colonies. U.S. Dep. Int., Fish and Wildl. Serv., Biol. Serv. Program, FWS/OBS 37/80. 371 pp. 46 Accepted 19 March 1983 NOTES A CRESTED AUKLET FROM BAJA CALIFORNIA ROBERT PITMAN, Southwest Fisheries Center, National Marine Fisheries Service, P.O. Box 271, La Jolla, California 92038 (present address: Oregon Institute of Marine Biology, Charleston, Oregon 97420) MICHAEL NEWCOMER, Southwest Fisheries Center, National Marine Fisheries Ser- vice, P.O. Box 271, La Jolla, California 92038 (present address: Department of Biological Sciences, San Jose State University, San Jose, California 95192) JOHN BUTLER, Southwest Fisheries Center, National Marine Fisheries Service, P.O. Box 271, La Jolla, California 92038 JAMES COTTON, Southwest Fisheries Center, National Marine Fisheries Service, P.O. Box 271, La Jolla, California 92038 GARY FRIEDRICHSEN, Southwest Fisheries Center, National Marine Fisheries Ser- vice, P.O. Box 271, La Jolla, California 92038 (present address: P.O. Box 890, Ar- eata, California 95521) On 7 July 1980, while conducting a marine mammal survey for National Marine Fisheries Service, we discovered a Crested Auklet (Aethia cristatella) 9 miles ESE of Cedros Island (27°59'N, 115°00'W), 300 miles south of the United States— Mexico border. In the flat calm water in the lee of Cedros we were able to study it for 10 minutes during midday from a distance of 75 m using mounted 25x 150 mm spotting binoculars. The bird was a stunning adult in breeding plumage. Its size was intermediate be- tween Cassin’s Auklet {Pt^;choramphus aleuticus) and Rhinoceros Auklet (Cerorhinca monocerata) , both seen during the day. As it sat on the water it was entirely dark grey, its plumage appearing recently renewed with no evident signs of wear. The prominent bill was bright red (or reddish-orange), stout, laterally compressed and had a somewhat rounded appearance when viewed from the side. Also prominent was a line of white plumes extending backwards from the eye and a tuft of grey feathers aris- ing from the base of the upper mandible and curling forward. The eye was pale yellow with a black pupil. As we approached the bird, it started nervously dipping its head into the water, which wetted the tuft of feathers and caused them to droop over onto the bill. These drooping feathers must have annoyed the bird because after each dip it quickly flicked its head to the side to throw the water off, allowing the tuft to bounce back up and out of the way. The bird appeared quite healthy and alert as it sat preen- ing in 66 °F (19°C) water. As we approached within 75 m, the auklet whirred off, landing about 1 km away. We turned to follow, but the bird was lost among Craveri’s Murrelets (Si^nthliboramphus craueri) in the area. This sighting represents the first record of a Crested Auklet for Mexico and only the third record for North America exclusive of Alaska. In a recent paper, Weyman (Con- dor 82:472, 1980) reported the only Crested Auklet record for California and sum- marized the other known extralimital records for the species. Interestingly, both the California record and our Baja California sighting occurred in July. Western Birds 14: 47-48, 1983 47 NOTES While searching for any additional records, we were provided with information on an early record for British Columbia: R. Wayne Campbell located a Crested Auklet specimen (no. 11915) in the collection of the British Columbia Provincial Museum. The specimen was collected by a sealer (J.M. Lindley) offshore in the latitude of Kyu- quot North West, Vancouver Island, British Columbia, in the winter of 1892-1893. This specimen represents the only record for Canada and the earliest known record of a Crested Auklet for North America outside of Alaska. As our sighting is an isolated record, it seems highly unlikely that environmental per- turbations (e.g., storms, changes in ocean climate) could have forced this boreal species so far south of its normal range. Instead, this occurrence probably again demonstrates the ability of individual seabirds, even species not particularly renowned for their flight capabilities, to turn up as extralimital strays almost anywhere. We wish to thank R. Wayne Campbell for providing information on the British Col- umbia record. Accepted 13 Januar^i 1983 48 Crested Auklet Sketch by Narca Moore NOTES NOTES ON THE DISTRIBUTION AND BIOLOGY OF THE FLAMMULATED OWL IN CALIFORNIA PETER H. BLOOM, Department of Bioloqu, California State University, Long Beach, California 90840 Although the Flammulated Owl (Otus ffammeo/us) is thought to be considerably more common than once suspected (Marshall 1939; Winter 1974, 1979), new data are scarce. Winter (1974, 1979) has provided an excellent analysis of the species’ distribution and seasonal occurrence in California, but much remains to be learned about other aspects of its biology. This paper provides data on four previously un- published distributional records, three nesting attempts in nest boxes, and further in- formation on body weight and molt. Observations of Flammulated Owls during this study were largely incidental to data collection for other field surveys: the Point Reyes Bird Observatory’s Beached Bird Survey; and the American Kestrel Nest Box Program of the Susanville District of the Bureau of Land Management. Flowever, the two observations of birds in the Warner Mountains were obtained by deliberately setting mist nets for the species in suitable habitat. RESULTS On 1 July 1974, approximately 1 km north of the mouth of the Santa Margarita River, Camp Pendleton Marine Corps Base, San Diego County, I found a badly de- composed, partially feathered, headless specimen (California State Univ. Long Beach 5546) on the beach. The bird was found in the surf and is thought to have died at sea within 2 weeks prior to my finding it. Positive identification was made by a comparison of the skeletal remains with those of all small southwestern owls, including the Flam- mulated Owl. The habitat directly adjacent to where the owl was found is coastal sage with no suitable nest trees. On 12 September 1976, approximately 4.8 km north of Fandango Pass on the east side of the Warner Mountains, Modoc County, I captured two Flammulated Owls at night with mist nets. The dominant tree species at this location were White Fir (Abies concolor) and Ponderosa Pine (Pinus ponderosa). The area had been previously logged and the majority of the trees present were 5-10 inches in diameter breast height (DBH) . Both birds were weighed, banded and examined for molt. The larger of the two owls, 1143-02434, had a body weight of 70 g and was undergoing extensive molt of the body and flight feathers. On both wings primaries 8-10 were ensheathed and growing in. Primaries 1-7 had been recently replaced and were new and unworn. Secondary molt was also symmetrical except for number 9, which was new on the left wing and growing in on the right wing. Secondaries 1,2, 3, 5, 6 and 10 were new, and 4,7 and 8 were growing in on both wings. All rectrices were new and the bird was undergoing a heavy body molt of contour feathers. To my knowledge, no species of the genus Otus molts flight feathers during its first fall. Since this bird was undergoing an extensive body and flight feather molt, it was almost certainly an adult (after hatching year) and probably a female. Sex determina- tion was based on its relatively large size with respect to the second individual. I caught the second individual several hours later, 20 m away. It was not molting any flight feathers, but was undergoing a heavy body molt. The bill was smaller com- pared to the presumed female; the body weight was 63 g. This bird was felt to be recently fledged (hatching year) and most likely a male. Western Birds 14; 49-52, 1983 49 NOTES On 11 July 1978, 2.4 km north of the shore of Eagle Lake, Lassen County, 1 found an adult female Flammulated Owl incubating 3 eggs. The nest was 6 m above the ground in a south-facing nest box, attached to a Ponderosa Pine (Figure 1) . The domi- nant tree in the area, which had been previously logged in 1959, and pre-commercial- ly thinned in 1968, was Ponderosa Pine with occasional Western Junipers (Juniperus occidentalis) . The topography in the immediate vicinity of the nest tree was flat, but with nearby low rolling hills. Most trees within 200 m of the nest tree had a DBH of ap- proximately 10 inches but ranged up to 48 inches. On 22 July 1978 I reexamined the nest box and banded the adult female (1143-73994). The box contained 3 young ap- proximately 10 days old, indicating that the eggs were near hatching when the box was first checked. When checked again on 3 August 1978, the 3 young were near fledging and capable of 1.5 m flights. On approximately 10 August, the nest box was empty and the young were presumed to have fledged. The nest site was reexamined several times during the 1979 breeding season but no activity was noted. When banded, the adult female weighed 69 g and was initiating molt of the primaries. Primaries 2 and 3 were growing in while primary 1 had been recently replaced. Primaries 4-10 were old and worn. All secondaries were new. No rectrix or body molt was observed. On 25 June 1980 S. Hawks observed an adult Flammulated Owl incubating 3 eggs in this same box. The adult female banded on 22 July 1978 was recaptured on 21 July 1980 in the nest box with 3 young which were 14-17 days old. When examined in early August, the nest box was empty and the young presumably fledged. When recaptured, the female weighed 62 g and was completing a molt similar to, but more asymmetrical than, that observed in 1978. Primaries 4-10 were old on both wings. Primary 1 was new on the left wing and primaries 1-3 were new on the right wing. The only primaries growing in were 2 and 3 on the left wing. All secondaries were new except 5 which was old. 1 again found the box to be active on 9 July 1981. Although the attending adult was not captured, it responded much like the previous occupant and perched on the same limbs utilized in 1980. I suspect that this was the same owl that was banded here in 1978 and eecaptured in 1980. When checked, the box contained 3 young approximately 2 weeks old. One of these birds was about 1 week behind in development relative to its nest mates and ap- peared to be ill. It was taken from the nest box, but died in captivity after 8 hours. The probable cause of death was a long strand of horsehair that was lodged deep in the digestive tract with an end protruding 5 cm out of the mouth. Efforts to extract the hair were unsuccessful. Both of the bird’s nest mates had fledged by the time the box was rechecked on 23 July. When last observed in July 1982, the nest box had been taken over by Douglas Squirrels {Sciuros douglassi; S. Hawks pers. comm.). DISCUSSION The Camp Pendleton specimen is the second of only 2 known coastal occurrences, both in San Diego County, of the Flammulated Owl in California (Banks 1964, Winter 1974) . This specimen is even more unusual since this particular bird was substantially outside of the normal breeding range in a non-migratory season. Perhaps the best ex- planation is that it represents an extremely late migrant which wandered out to sea and died before washing ashore. The two individuals that were mist netted in the Warner Mountains add more documentation to that reported by Johnson (1970) for this mountain range. How- ever, no breeding has been confirmed, despite the fact that these observations range from 11 June (Johnson 1970) to 12 September (this study). 50 NOTES The three nest records from July 1978, 1980 and 1981 at Eagle Lake represent the first breeding records of this species from Lassen County. A female Flammulated Owl found dead in aquatic vegetation along the west side of Eagle Lake in May 1971 by G. Gould (Humboldt State University 2868) indicates the possibility of other breeding ac- tivity in this area. The three nesting occurrences by the Eagle Lake female in a kestrel nest box are of particular interest. The use of artificial nest boxes by the species has been reported only rarely (Hasenyager et al. 1979). Further, this Eagle Lake observation represents the first documentation of a female Flammulated Owl using the same nest site over several years. A description of the kestrel nest box utilized is presented elsewhere (Bloom and Hawks 1983). Molt data collected from the adult female banded in the Warner Mountains and from the adult female banded at Eagle Lake indicate the primaries are replaced during the summer and early fall, between approximately 1 July and 25 September. Second- ary molt apparently largely precedes the primary molt and is initiated by about 1 June and completed by 30 September. Since all rectrices were new in July, they were presumably replaced in May and June, perhaps simultaneously, as is true of several species of small owls (Mayr and Mayr 1954, Collins 1961). A complete molt of all remiges and rectrices of Flammulated Owls can be expected to last 4 months, between approximately 1 June and 30 September. Winter (1974) observed a captive juvenile from the central Sierra Nevada that underwent a heavy body molt in mid-September. As this was the same condition that I observed in the male captured in the Warner Mountains, I feel that the age was cor- rectly ascertained. Figure 1. Adult female Flammulated Owl standing at entrance to the nest box cavity in Lassen County, California, 10 July 1978. Photo by P.H. Bloom 51 NOTES ACKNOWLEDGMENTS For comments on earlier drafts of this manuscript, I would like to thank Charles Col- lins, Jon Winter, Gordon Gould and Melinda Leach. Robert Walker assisted with the installation of the Eagle Lake nest box and Stephen Hawks provided additional field observations of the adult and young Flammulated Owls. James Northern provided Flammulated Owl skeletons for comparison with the Camp Pendleton specimen; David Bontrager and Charles Collins helped verify its identification. Stanley Harris provided data on the Eagle Lake specimen. This study was funded partially by the U.S. Department of the Interior, Bureau of Land Management, Susanville District. LITERATURE CITED Banks R.C. 1964. An experiment on a Flammulated Owl. Condor 66:79. Bloom, P.H. & S.J. Hawks. 1983. Nest box use and reproductive biology of the American Kestrel in Lassen County, California. Raptor Res. 17(1): in press. Collins, C.T. 1961. Tail molt of the Saw-whet Owl. Auk 78:634. Hasenyager, R.N., J.C. Pederson & A.W. Heggen. 1979. Flammulated Owl nesting in a squirrel box. West. Birds 10:224. Johnson, N.K. 1970. The affinities of the boreal avifauna of the Warner Mountains. California. Occas. Pap. Biol. Soc. Nevada 22:1-111. Marshall, J.T. Jr. 1939. Territorial behavior of the Flammulated Screech Owl. Con- dor 41: 71-78. Mayr, E. & M. Mayr. 1954. The tail molt of small owls. Auk 71:172-178. Winter, J. 1974. The distribution of the Flammulated Owl in California. West. Birds 5:25-44. Winter, J. 1979. The status and distribution of the Great Grey Owl and the Flammu- lated Owl in California. Pp. 60-85 in P.P. Schaeffer & S.M. Ehlers, eds. Owls of the west: their ecology and conservation. Proc. Natl. Audubon Soc. Sym- posium. 106 pp. Accepted 4 September 1982 Flammulated Owl Sketch by Cameron Barrows 52 NOTES NOCTURNAL MOONLIGHT CALLING BY ELEGANT TROGON IN ARIZONA BRUCE G. ELLIOTT, California Department of Fish and Game, 2201 Garden Road, Monterey, California 93940 On 29 June 1982 1 heard extended post-dusk calling by an Elegant Trogon (Trogon elegans) in the South Fork portion of Cave Creek Canyon, Chiricahua Mountains, Cochise County, Arizona. There was a half-full, waxing moon and light intensity in the canyon due to both direct and cliff-side reflected light was sufficiently bright to see many details of the South Fork Creek riparian vegetation quite clearly. The bird com- menced calling at 2112, approximately 45 minutes after all noticeable solar illumina- tion had concluded. The bird called a series of the typical turkey-like “cory-cory-cory” notes at intervals of about 20 seconds for at least 17 minutes, and last call series noted occurring at 2129. During the ra t/> (V u «3 cn c ’5) (O Ci) V) (O _) csi -Si X) (0 t-" oi 3 00 OS c 3 "3 o CO 00 OS 3 CO CM OS w C < (- O h“ U- O H 2 UJ U DO UJ a. >. 10 ■ c 3 CO CM c 3 "3 o LO o c o (O c75 sOCMLf)CO«— lOr^MsO'OiOOO'— ' CO ^ L0 ocor^>-iot^co»-iomooo >-i CO CM oooor^oococMOor^ooo .5 00 ^ Os Q UJ > on UJ c/5 CQ O o O 5 o ^ 00 < os ^ OS ^ o ^ CM o 1 m csi >-< CO CM o + I o o< so O lO I M u-i CM CM SO sOCMr'-CMOSOCMCOCO+COOO + ICMOO |o ^ ’ — ' ’ — ' CM ’ — ' » — ' c\] 00 OS o cn ■5 o CM 2 CM T-Hoooco>-''-Hr^cosooooO'— 'O OsOOO'-'^OOCMO'-^OiOr^ o o >— < I o csi CM X 000 I o 0(5 so O CO CM CO CVJ ^ I •-HSOOSOOSDOS^'OO O X OS ^CJSsOXXOSr^CM IXOXs^tOOOXO^ >-H CM O X OS CM X X X rj- X t-H t-H t-H CNJ CMrHo^^oooc^Jo^^ -D ro o os 15 c c c c c c c c c c c UL (/> (/> (0 to <0 <4-^ 10 10 10 10 10 10 10 10 10 10 10 V to to c c c X cu cu cu cu cu cu cu cu cu cu lU p p ‘C 'C 10 CJ u IJ u CJ CJ u CJ CJ CJ CJ (0 (0 <0 to I 0 0 0 0 0 0 0 0 0 0 0 3 10 10 E E E £ u) 10 to c IO u to 0) -*-< 3 c (U > *x cn c c 3 X X cu c 'i 5 cu X c cu X k> cu to X o 3 > ,0 c ^ 10 C T! “ ^ c c CTI 0 > (0 (/) 10 ^ n ^ (U k- J= E c £Xv4_ r- “ cu O O C *“ fc- O on cu X X X c X S S! 5 -a E o 10 cn 2 3 J CQ = o Z TO XI 10 >*: u c o number of means from all stations on a given date. ‘^Main activity of breeding colony — courtship. ®Main activity of breeding colony — egg laying and incubation. *Main activity of breeding colony — feeding of chicks. ^Main activity of breeding colony — dispersal of fledglings. LEAST TERN FORAGING ECOLOGY 3 "3 CO 00 ON CMOOOt^OOOOmTfOOCOt^OOOOOO (M T— I (NJ CO CTv 3 00 ON O O ON lO th NO m lO 'X) CM CM I— I CO + IOOOOOCOOCM Ifi CO 00 ON I o 00 ON cn c 'C 3 T3 c 3 o u 0) cn c (0 CMOOuo^'d'Oor^ooiomooo^oor^ .o -c il, CO CM .-H ^ U t-h UJ § "c„ CO UJ 3 to "3$ O^t^C 0 '-'^C 0 C 0 + + + + +OCMCMOOOO CO CO CQ (NJ >_ "n <0 ^ ^ SS OOOOOt^'XlOONCOCOr^ONOCOCOOOOCO < 00^ -H CM ^ ^ MO O ^ u. ^ -D < ^ 00 Son fOCM'OCMOCOlfiOOCOOOOvDOOOOOOON O CO r- ^ ^ f- o u. 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CM CO CM < § CM t— ^ 00 3 ■a c 3 o u o cn 0) c (0 to r; CM ’-I ^ lO o H 0) Z § CM W +O^'^'cor^— |OOOOOCOOOOOOOOOOO'-ICOCO+ lO QJ ^ ON DC S LU ° CL w TO ^ »— < CO CM ^ 00 00 in in rtinO'-'^OONOOO + +COCM+CMOOOOOOONO-OOON^ CM CM CO CM NO £ ‘C to cn to s to c to c/) -D TO CM s 00 CJN o "O CO o NONOoooNin^ooo + 'Oin'- 05 H -4-^ f/) to Q) <0 c c: c c c c c to to to to to 10 to jO Oi 0) 0> 0> cv cu fC u u u u u u u X 0 0 o o o 0 0 c c c O O O _c o o c •£ *£ cn cn cn 3 a iS JS *^0 0 ic j: ^ E E — jn m ijO ^ ^ O ^ ^ 0) ^ .> to <0 tQ '3 ‘C k. u u> -O -D ^ to 3 in c c c c c c c c to to 10 to JZ JZ JZ J= u u u u ka ka ka ka Oi Cl) > > > 'C ’C ‘kT tn j- to lO 6 " ,:3 ,:3 ^ ^ k- U- k- iM to V T3 T3 to ka 0> on T3 0) to ka T3 cn o> TJ ^ QJ ^ j: JC -iC (Q (Q (Q ^ ^ ^ " "V "V "V "V "V ooooo222c a a a a a .E •£ E ■= ka k« k« ka ka (Q A (Q (C C lO (C tQ lO to 5 5 5 5 5 -c j: -c j: -c (/)(/) V) (/) c/) 0> ^ V 0) E £ E 0> N 'in JW D. E TO tn _Q) 10 H c o TO i75 CM CO Nt in NO r^ 'o CMCo’^invDC'OOONO'-'CMco^LnNOr^oooN ,-h.-i,-(.-i,-it-i,-ii— ICMCMCMCMCMCMCMCMCMCM ^Location of observation stations as indicated in Figure 3. '’■^See explanations, Table 2. more detailed description of foraging activity at Station 5 is provided in Minsky (1982). Station 11 was dry after 13 July; stations 10 and 12 were occasionally dry throughout the study period. San Luis Rey River mouth was blocked after 18 May. LEAST TERN FORAGING ECOLOGY Table 5. Effect of distance from nesting area on Least Tern foraging activity. Date 0- 1 Distance from 1 - 2 Nesting Site (miles) 2-3 3-4 Huntington Beach 05 May 1980 25 60 15 0 06 Jun 1980 60 39 1 0 20 Jun 1980 42 28 30 0 21 Jul 1980 53 33 14 0 05 May 1981 48 25 21 2 18 May 1981 52 16 29 3 02 Jun 1981 60 9 27 4 17 Jun 1981 45 46 7 0 01 Jul 1981 34 48 15 2 13 Jul 1981 64 28 7 0 Mean (X) 48.3 33.2 16.6 1.1 Venice Beach 06 May 1980 41 25 21 13 04 Jun 1980 71 17 12 0 23 Jun 1980 44 21 31 4 22 Jul 1980 59 18 9 16 04 May 1981 11 7 72 0 19 May 1981 69 6 24 0 01 Jun 1981 54 7 20 2 23 Jun 1981 80 20 0 0 30 Jun 1981 49 41 5 0 14 Jul 1981 44 39 9 2 Mean (X) 52.2 20.1 20.3 3.7 Santa Margarita River 03 May 1982 17 20 51 11 04 May 1982 12 42 23 16 18 May 1982 27 19 39 5 01 Jun 1982 36 48 15 0 02 Jun 1982 27 64 7 0 18 Jun 1982 39 46 15 0 29 Jun 1982 55 39 4 0 13 Jul 1982 56 22 14 5 27 Jul 1982 26 22 19 7 28 Jul 1982 42 0 7 15 11 Aug 1982 70 12 0 0 Mean (X) 37.0 30.4 17.6 5.4 4 - 5 *’ 3 0 0 2 0 3 1.3 9 1 16 0 5 6 6.2 3 6 13 0 0 0 0 1 25 34 19 9.2 “Values indicate percent of foraging activity occurring at stations located given distances from nesting sites. ^’Stations at distances of 4-5 miles from nesting sites were not established at Venice Beach and Huntington Beach until 1981. 68 Table 6. Principal foraging localities used by Least Terns at three major breeding colonies. LEAST TERN FORAGING ECOLOGY ON (N 00 (N d) 0) cu SI eg 1 1 <=> •4-1 c cu go eg 1 1 "S (A 1 m ir> eg 1 - 1 o cu X) £ eg 1 1 ^ 3 c CO eg 1 1 o T 3 cu CJ (0 eg eg 1 1 C 5 o DO eg 1 1 ^ (A o eg o eg o g "to os t-h o o o CJ _g 00 eg i-H o CD c "L cu s> o o o lU E D N£l >-H O O •o cu _N 2 c lO o eg o 3 g (0 C?) rH --H o o > (0 cu CO o o o X •4-^ if) (N T—i o E t-H I-H o O Q} . -C OS 00 NO in CO eg o o o CO CSJ I CO CM I vO vO eg kO kO ^ --I eg eg eg CO eg o --H o --I 0) > DC <0 (O _ (k> .-ti -O rn t; ra c P O s cu c cj c (O C ^ c > X (/) CO T3 ^ g «j on cu .-H E T3 « « 2 d> tn V) to $ 3 on cu s: X c r, c -2 ^ fO T3 CP -*-• r- s:§ D T3 C TD C i/> 10 U) C o 10 2 >*- t/) o ^ o c <-> O _c t/> u cu <0 0) c g ■(0 > d) (A o so iM cu CU JO SS C 10 E 3 O c — cu 10 .C 0.99). Similarly, differences in success as related to nest heights were not statistically significant. Three of 6 nests (50%) placed from 0 to 1.5 m above the ground were successful; 21 of 38 (55%) in the 1.6- to 3.0-m interval were successful; 13 of 23 (56%) in the 3.1- to 4.5-m interval were successful; and 6 of 11 (54%) above 4.6 m were successful (x^ — 0.11, df = 3, P>0.99). NESTLING AND FLEDGLING PERIOD The period from hatching to fledging averaged 20.0 days (s.d. = 2.61, range = 16 to 26 days, n = 27). The mean nestling period likely would have 155 SCRUB JAY NESTING ECOLOGY been longer, but the young at three nests left the nest during my visits late in this period (16+ days). The nesting period for Florida Scrub Jays ranged from 12 to 21 days but seemed to vary with the amount of human handling (Woolfenden 1978) . Nestling periods among Scrub Jays in Monterey County ranged from 20 to 24 days (Verbeek 1973). The average number of young fledged per breeding effort (mean clutch size X probability of success) was 1 . 1 for all nests found and 1.5 considering only active nests. Florida Scrub Jays raised an average of 1.1 fledglings per com- pleted nest (Woolfenden 1973). On a comparable basis, Scrub Jays in this study raised 1.4 fledglings per completed nest. Parents of four broods continued to feed their young an average of 34.3 days (s.d. = 2.87, range = 32 to 38) after they had fledged. This cor- responds approximately to the time when young are reported to begin their postjuvenal molt (about 5 weeks post-fledging— Pitelka 1945) . Young in this study were first noticed actively foraging 20 days after fledging, but 1 did not determine at what age the young became self-sufficient. Atwood (1978) found evidence of Santa Cruz Island Scrub Jays feeding young 60 days after fledging. Adult Pinyon Jays continued to feed their young even after they were proficient at foraging (Baida and Bateman 1971). RENESTING AND SECOND NESTING Renesting always involved the construction of a new nest from new materials, with building continuing up to the time of egg-laying. Renesting oc- curred even among pairs whose initial attempts failed as late as the late nest- ling stage. The period from loss of eggs or young to egg-laying in a renesting attempt averaged 8.8 days (s.d. = 1.98, n = 8, range = 7 to 12 days). The renesting interval in Florida Scrub Jays was between 8 days and 2 weeks (Woolfenden 1973). Among 31 pairs successful with their first nesting attempt, only one (3%) at- tempted a second nesting. In late May 1971 , that pair was observed building a new nest while still involved in territorial defense and the feeding of fledglings from their first nest. The fledglings were estimated to be about 31 days old, from hatching, when building of the second nest began. Construction of the second nest took 5 or 6 days. Five eggs were laid in the second clutch, begin- ning 5 days after the second nest was complete. Feeding of the fledglings from the first nest continued into the incubation period at the second nest. Late in the incubation period however, feeding of the fledglings ceased, and they were driven from the nest tree by the adults but were tolerated elsewhere in the territory. Shortly after the hatching of the second clutch, the fledglings from the first nest were no longer observed in their parents’ territory. Woolfenden (pers. comm.) found a 13% frequency of true second nesting attempts among Florida Scrub Jays. Clutch overlap as a reproductive tactic (Burley 1980) may be more common in the Chico Scrub Jay population than indicated by my results, because of the increasing difficulty of following pairs through time and space when foliage development is complete, 156 SCRUB JAY NESTING ECOLOGY ACKNOWLEDGMENTS I am grateful to Michael Erpino for the opportunity to conduct this study. Michael Erpino, Steve Ervin, Jared Verner and Glen Woolfenden gave help- ful comments on the manuscript. The field work was conducted while I was a graduate student in Biological Sciences at California State University, Chico. This work was supported in part by a National Science Foundation grant. LITERATURE CITED American Ornithologists’ Union. 1957. Check-list of North American birds. 5th cd. Am. Ornithol. Union, Baltimore, MD. Atwood, J.L. 1978. The breeding biology of the Santa Cruz Island Scrub Jay, Aphelo- coma coerulescens insularis. M.A. thesis, California State Univ., Long Beach. Atwood, J.L. 1980a. Social interactions in the Santa Cruz Island Scrub Jay. Condor 82:440-448. Atwood, J.L. 1980b. Breeding biology of the Santa Cruz Island Scrub Jay. Pp. 675- 688 in D.M, Power, ed. , The California Islands: proceedings of a multidisciplinary symposium. Santa Barbara Nat. Hist. Mus., Santa Barbara, CA. Baida, R.P. & G.C. Bateman. 1971. Flocking and annual cycle of the Pinyon Jay, Gi^mnorhinus cijanocephalus. Condor 73:287-302. Baida, R.P. & G.C. Bateman. 1972. The breeding biology of the Pinyon Jay. Living Bird 11:5-42. Bent, A.C. 1946. Life histories of North American jays, crows, and titmice. Bull. U.S. Natl. Mus. 191. Best, L.B. 1978. Field Sparrow reproductive success and nesting ecology. Auk 95: 9-22. Best, L.B. & D.F. Stauffer. 1980. Factors affecting nesting success in riparian bird com- munities. Condor 82:149-158. Brown, J.L. 1963. Social organization and behavior of the Mexican Jay. Condor 65: 126-153, Burley, N. 1980. Clutch overlap and clutch size: Alternative and complementary repro- ductive tactics. Am. Nat. 115:223-246. Davis, D.E. 1955. Breeding biology of birds. Pp. 264-308 in A. Wolfson, ed.. Recent studies in avian biology. Univ. Illinois Press, Urbana. Davis, W.B. 1953. The span of the nesting season of birds in Butte County, California, in relation to their food. Condor 35:151-154. Erpino, M.J. 1968. Nest-related activities of Black-billed Magpies. Condor 70:154-165. Hardy, J.W. 1961. Studies in behavior and phylogeny of certain New World Jays (Garrulinae) . Univ. Kansas Sci. Bull. 42:13-149. Hester, A.E. 1963. A plastic wing tag for individual identification of passerine birds. Bird-Banding 34:213-217. Hinde, R.A. 1956. The biological significance of the territories of birds. Ibis 98:340- 369. Holyoak, D. 1967. Breeding biology of the Corvidae. Bird Study 14:153-168. Johnson, D.H. 1979. Estimating nest success: The Mayfield method and an alterna- tive. Auk 96:651-661. Jones, R.E. & K.E. Hungerford. 1972. Evaluation of nesting cover as protection from magpie predation. J. Wildl. Manage. 36:727-732. Kendeigh, S.C. 1963. New ways of measuring the incubation period of birds. Auk 80: 453-461. Klomp, H. 1970. The determination of clutch-size in birds. A review. Ardea 58: 1-124. 157 SCRUB JAY NESTING ECOLOGY Mayfield, H. 1961. Nesting success calculated from exposure. Wilson Bull. 73:255- 261. Mayfield, H. 1975. Suggestions for calculating nest success. Wilson Bull. 87:456-466. Mulder, B.S., B.B. Schultz & P.W. Sherman. 1978. Predation on vertebrates by Clark’s Nutcracker. Condor 80:449-451. Nolan, V., Jr. 1963. Reproductive success of birds in a deciduous scrub habitat. Ecol- ogy 44:305-313. Odum, E.P. & E.J. Kunezler. 1955. Measurement of territory and home range size in birds. Auk 72:128-137. Owen, D.F. 1959. The breeding season and clutch size of the Rook, Coruusfrugilequs. Ibis 101:253-239. Pitelka, F.A. 1945. Pterylography, molt, and age determination of American jays of the genus Aphehcoma. Condor 47:229-260. Pitelka, F.A. 1951. Speciation and ecologic distribution in American jays of the genus Aphehcoma. Univ. California Publ. Zool. 50:195-464. Ricklefs, R.E. 1969. An analysis of nesting mortality in birds. Smithsonian Contrib. Zool. 9:1-48. Ritter, L.V. 1972. The breeding biology of Scrub Jays. M.A. thesis, California State Univ., Chico. Stallcup, J.A. & G.E. Woolfenden. 1978. Family status and contributions to breeding by Florida Scrub Jays. Anim. Behav. 26:1144-1156. Stewart, R.M., S.M. Long & M. Stewart. 1972. Observations on the nest behavior of the California Scrub Jay. Calif. Birds 3:93-95. Verbeek, N.A.M. 1973. The exploitation system of the Yellow-billed Magpie. Univ. California Publ. Zool. 99:1-58. Woolfenden, G.E. 1973. Nesting and survival in a population of Florida Scrub Jays. Living Bird 12:25-49. Woolfenden, G.E. 1975. Florida Scrub Jay helpers at the nest. Auk 92:1-15. Woolfenden, G.E. 1978. Growth and survival of young Florida Scrub Jays. Wilson Bull. 90:1-18. Woolfenden, G.E. & J.W. Fitzpatrick. 1978. The inheritance of territory in group- breeding birds. BioScience 28:104-108. Accepted 3 April 1 983 158 BREEDING BIOLOGY OF THE BLACK-HEADED GROSBEAK IN NORTHERN UTAH GARY RITCHISON, Department of Biology, Utah State University, UMC 53, Logan Utah 84322 (present address; Department of Biological Sciences, Eastern Kentucky University, Richmond, Kentucky 40475) Although the Black-headed Grosbeak (Pheucticus melanocephalus) is a common breeding bird in many parts of western North America, little is known about its breeding biology. Apart from a few anecdotal reports (Bent 1968), information on the breeding biology of this species comes from a single study performed in California (Weston 1947). The objective of the present study was to examine the breeding biology of a population of Black- headed Grosbeaks in northern Utah. STUDY AREA The study was conducted at Malibu-Guinavah Forest Camp (Cache Na- tional Forest) , 10 km east of Logan, Cache County, Utah. The area, at 1500 m elevation, is located on the flat bottom of Logan Canyon, with the Logan River cutting diagonally across the eastern section. The vegetation is discon- tinuous woodland, which is characterized by a heavy growth of grasses in the open areas and a dense understory of wild rose (Rosa woodsii), Blue Elderberry (Sambucus coerulea), hawthorn (Crataegus riuularis) , Chokecherry (Prunus uirginiana), and Sierra Willow (Salix wolfii). The domi- nant trees in the area are Box Elder (Acer negundo), Dusky Willow (Salix melanopsis) , and River Birch (Betula fontinalis) . Numerous Mountain Alder (Alnus tenuifolia) can be found along the stream banks with occasional Nar- rowleaf Cottonwood (Populus angustifolia) and Green Ash (Fraxinus lanceolata) dispersed over the area. Because of recreational improvements by U.S. Forest Service personnel, the canopy is discontinuous. METHODS I made field observations almost daily from 1 April through 31 August in 1977 and 1978 at the Malibu-Guinavah Forest Camp. Approximately 850 hours were spent observing birds or nests and observations were equally dis- tributed throughout the day. Territorial boundaries were delimited by plotting on a map those locations where intraspecific aggressive behavior occurred. If a part of a territory could not be determined by observation of boundary disputes, the outermost points of utilization were connected by straight lines to form a polygon of maximum size. Hatching dates were obtained by inspecting the nests. When this was impossible, these dates were estimated within 1 or 2 days on the basis of the behavior of the adults. In all cases, either fledging was observed, or young known to have been in the nest the previous day were seen in nearby trees or shrubs a day later. Thirty-one adults (24 males and 7 females) were captured and marked with combina- tions of colored leg bands, numbered aluminum bands, and felt pens. In ad- dition, 21 nests were located, and colored and aluminum bands were placed Western Birds: 14:159-167, 1983 159 BLACK-HEADED GROSBEAK BREEDING BIOLOGY on 20 nestlings. Observations at such nests were made with 7 x 35 binoculars at distances of 4-8 m, using natural vegetation as a “blind.” A stopwatch was used to time the activities of breeding adults. RESULTS AND DISCUSSION The first birds arrived in the study area during the first 2 weeks in May. Although Weston (1947) reported that males arrive about 6 days before the females, my observations indicated that many of the first birds to arrive were already paired. Grosbeaks continued to move into and through the area for the next 2 weeks or longer. Banding returns suggested that the first birds in the study area were often those that nested in the area the previous year. These birds, however, did not always remain in the study area. Six birds banded in 1977 were observed in the study area early in the 1978 breeding season; two of these previously banded birds (one male and one female) re- mained to nest in the study area. Because many birds arrived already paired, observations of courtship behavior were limited. Weston (1947:55) stated that “the only type of display seen was a nuptial flight,” i.e., the male uttered loud songs from some exposed perch near a female and then suddenly flew out, performing a song-flight in the air above the female. My observations indicated that such song-flights were not utilized solely for courtship. On several occasions males were observed performing song-flights during “singing duels” with neighbor- ing males. The Pair Bond During the early part of the breeding season (before nesting began) , paired birds foraged together within their territories. Females usually followed as the males moved through the territory feeding and singing. Paired birds sometimes fed as close together as several centimeters, or more commonly in different parts of the same tree or bush or in adjacent trees or bushes. Vocalizations given by the birds as they moved through their territories in- cluded chip and wheet calls. Chip calls were given by both sexes and ap- peared to function as location calls. Wheet calls were given only when a bird was moving, e.g., when flying a short distance from bush to bush or when flying from the nest after incubating the eggs. As stated above, males often sang as they foraged. Such song apparently served a territorial function and was probably used by the female in maintain- ing contact with the male. Females infrequently sang while foraging near the male (Weston 1947; pers. obs.). Female song has also been reported in the Rose-breasted Grosbeak (Pheucticus ludouicianus; Ivor 1944a, Dunham 1965). Such song may play some role in pair-bond maintenance. Territorial Behavior In the Black-headed Grosbeak, singing by the male appears to be the most important factor in acquiring and retaining a territory. However, singing by itself is apparently not sufficient to maintain a territory. Early in the breeding 160 SONGS/HOUR OF OBSERVATION BLACK-HEADED GROSBEAK BREEDING BIOLOGY season agonistic encounters involving chasing and even physical contact oc- curred. Nearly all chases involved males, although several female-female chases were observed. On three occasions females were observed chasing males. No instances of actual physical contact were noted in these female- female or female-male encounters. Weston (1947:56), however, described a conflict between mated pairs in apparent defense of their respective territories in which the females were more aggressive than the males. The females “repeatedly postured and flew at each other, and at each attack, loud songs, calls, and sounds of bodily contact could be heard.” Weston reported no other instances of female song in territorial encounters. I observed two in- stances of singing by females in such situations. On one occasion, a female chased a male and, upon landing, sang one loud song. On another occasion a female appeared to engage in a brief singing duel with a neighboring male. Following territory establishment, Black-headed Grosbeaks became pro- gressively less aggressive. This change in behavior was quantified in two ways. First, male singing rates tended to decline as the season progressed (Figure 1). A second indicator of this decline was the distribution of in- traspecific agonistic encounters (chases or actual physical encounters) . Figure 2 summarizes this distribution for the 1977 and 1978 breeding seasons. It is Figure 1. Singing rates of selected male Black-headed Grosbeaks during the 1977 and 1978 breeding seasons. 161 BLACK-HEADED GROSBEAK BREEDING BIOLOGY apparent that after egg-laying began there was a substantial drop in the number of encounters and, later, such agonistic behavior disappeared altogether. In the days prior to and immediately after the young left the nest, males and females responded weakly, if at all, to the presence of other grosbeaks. Similar behavior has been reported in the Rose-breasted Grosbeak (Dunham 1964). Territories in the study area averaged about 2.7 ha (n = 12, range: 1.9 - 3.9). Previous investigators of the Black-headed Grosbeak have not in- dicated territory sizes. However, Dunham (1964, 1965) found that the average size of 20 Rose-breasted Grosbeak territories was 0.8 ha (range: 0.3 - 1 . 8 ). Nest site selection and nest construction Nesting usually occurred in deciduous bushes and trees, usually at a height of 2-7 m above the ground (n = 21, x = 4.1). Weston (1947) listed height records for 163 nests and found the average to be about 3 m above ground. The nest is bulky and loosely constructed, and composed of slender twigs, plant stems, and rootlets. Nests were generally built by the female. Weston (1947:60) reported that he had “never seen a male carrying nesting material nor in any way aid in the actual construction of the nest.” However, Finley (1907) mentioned seeing a male grosbeak carrying a twig in his beak. On several occasions I observed Figure 2. Distribution of intraspecific agonistic encounters (chases and/or actual physical en- counters) among male and female Black-headed Grosbeaks (day 0 = first egg laid). 162 BLACK-HEADED GROSBEAK BREEDING BIOLOGY males assisting in nest construction. In all pairs observed, however, most of the construction was performed by the female. Construction of nests took from 3-4 days with most of the building occur- ring in the morning. Visits to the nest became less frequent and more ir- regular as the day progressed, and in the afternoon nests were sometimes visited without any nesting material. During the final stages of construction, females spent less time placing new material in the nest and, instead, spent more time readjusting material already there (Weston 1947; pers. obs.). Following the completion of the nest there was a period of 2-5 days before the first egg was laid. The eggs were laid at intervals of approximately 24 hours, and the usual set consisted of two to four eggs (x = 2.8, n = 14). Weston (1947) indicated that the average clutch consisted of 3.3 eggs (n = 192). Incubation Both sexes incubated during the day (Head 1902, 1904; Weston 1947; pers. obs.), while the female incubated at night (Weston 1947; pers. obs.). During the day, eggs were incubated about 97% of the time, about 41% of the time by males and 56% by females. The average length of each incuba- tion period for 10 males was about 35 minutes (range: 2.5 to 100) and for 10 females, about 51 minutes (range: 11 to 130). Both sexes were surprisingly vocal on and around the nest. Males fre- quently sang while incubating. At times this song appeared to be in response to the singing of neighboring males; i.e., a male that was quietly incubating would begin to sing upon hearing a neighboring male sing. At other times the male’s singing appeared to be a signal to the female. When a male’s period of incubation was due to end he often began to sing. Generally, the female ap- peared at the nest within a few seconds. Whereas incubating males often sang to inform the female of their ap- parent intention to leave the nest, incubating females appeared to convey the same information with chip calls. Males generally returned to the nest within a few seconds upon hearing their incubating mate’s call note. On many occasions a male or female approached the nest and found its mate quietly incubating. At these times, the approaching bird frequently ut- tered chip calls or sang. The incubating bird, upon hearing its mate, would then leave the nest (usually after uttering several chip calls) . Rose-breasted Grosbeaks also behave in this manner when changing places on the nest (Ivor 1944a, b; Allen 1916). As mentioned previously, when grosbeaks flew from the nest they nearly always uttered one or more wheet calls. Such calls apparently informed the mate that the bird on the nest was leaving and resulted in faster change-overs. Rarely were nests left uncovered for more than a few seconds (x = 9.7 sec, n = 74). The incubation period ranged from 12-14 days, with most eggs hatching at 13 days. Eggs in a clutch usually hatched on the same day, and in no case were more than 2 days required for the hatching of all eggs in a clutch. 163 BLACK-HEADED GROSBEAK BREEDING BIOLOGY Parental Care During the first few days post-hatching adults maintained the same “schedules” as when incubating. Both adults fed and brooded the young, and their behavior when changing places on the nest was similar to that dur- ing incubation, with one significant difference. During incubation an ap- proaching female usually uttered chip calls to inform the male of her presence but during the brooding period females were more likely to sing (Figure 3). After fledging, such songs were used by females to maintain con- tact with the young (Ritchison 1983). Males and females contributed equally to the feeding of the young through- out the nestling period. And, surprisingly, the number of feeding trips to the nest was found to remain rather constant throughout that period (Figure 4). Flowever, later in the nestling period adults appeared to bring larger food items, and they frequently brought more than one item per trip to the nest. As the young developed both parents spent progressively longer periods off the nest. By the 7th day post-hatching the parents brooded much less con- stantly, although the young were still covered a good part of the time (Figure 5). 42 47 Figure 3. Singing rates of selected female Black-headed Grosbeaks during the 1977 and 1978 breeding seasons. 164 BLACK-HEADED GROSBEAK BREEDING BIOLOGY On the 8th day the eyes of the young began to open, and by the 9th day they were usually wide open. At this stage the young were brooded infre- quently, the time spent brooding being dependent on the weather (Weston 1947; pers. obs.). Adults approaching the nest to feed the young usually vocalized, uttering either chip calls or songs. Upon the arrival of an adult at the nest, young grosbeaks immediately began to utter begging calls. At times young grosbeaks responded to the chip calls of their parents and began calling before the adults arrived at the nest. Young grosbeaks left the nest as early as the 9th day post-hatching, although departure at 10-14 days post-hatching was more common (x = 11.5, n = 21) . After leaving the nest the young scattered among the shrubs near the nest, perching on low branches. During the first few days after leaving the nest, the young were rather quiet. As the fledglings are unable to fly at this time, they remained within a restricted area and the adults appeared to have little trouble locating and feeding them (Weston 1947; pers. obs.). If, however, an adult was unable to locate a young bird, it would begin to utter chip calls and songs. Upon hearing their parents’ vocalizations, young grosbeaks responded by uttering phee-oo and hunger-distress calls. In this manner the parents and young were able to maintain contact. After the young attained flight (approximately 15 days post-hatching) main- taining contact between parents and young became more difficult. When parents had food for the young but were unsure of the location of the young, the parents uttered chip calls or, more frequently, songs. Upon hearing a Figure 4. Average number of feeding trips made by pairs of Black-headed Grosbeaks (n =8) throughout the nestling period. 165 BLACK-HEADED GROSBEAK BREEDING BIOLOGY parent sing, a young grosbeak would fly to within a few meters or less of the adult and, if not fed immediately, would begin calling. At this stage (2-3 weeks post-hatching) , family groups no longer remained within their territories. Because of this wandering, it was difficult to observe specific family groups over long periods and, therefore, the duration of such groups remains unknown. Weston (1947) reported seeing young grosbeaks being fed by adults in early August, but he was unable to determine the actual length of the dependent period. In the Rose-breasted Grosbeak, Watts (1935) and Dunham (1965) reported that adults continued to feed the young after they had molted into their first winter plumage in at least some cases, and the family groups remained together until migration. Ivor (1944a, b), however, reported adult Rose-breasted Grosbeaks striking young on the bill after feeding them, beginning 27 days after hatching. He suggested that this may have been a weaning procedure , the “adults still reacting to begging with food , but to the adult appearance of the young with aggression.” Since males appeared to leave the nesting area before the females or young, later in the season family groups consisted solely of females and their Figure 5. Average amount of time spent on and off the nest by pairs of Black-headed Grosbeaks (n = 8) throughout the nestling period. 166 Total time off nestC%) BLACK-HEADED GROSBEAK BREEDING BIOLOGY young {Weston 1947; pers. obs.) . Resident females and young began leaving the study area in early August, with the last groups leaving the study area in mid- to late August. Transients were seen in the area into early September. ACKNOWLEDGMENTS I wish to thank Keith Dixon for his guidance throughout this study. Also, thanks are extended to Jack Watson and Lee Jones for assistance in the field. This investigation was partially funded by grants from the Frank M. Chapman Fund of the American Museum of Natural History and from Sigma Xi. LITERATURE CITED Allen, F.H. 1916. A nesting of the Rose-breasted Grosbeak. Auk 33:53-56. Bent, A.C. 1968. Life histories of North American cardinals, grosbeaks, buntings, towhees, finches, sparrows, and allies. U.S. Natl. Mus. Bull. 237. Dunham, D.W. 1964. Behavior of the Rpse-breasted Grosbeak, Pheucticus ludovi- cianus. Unpubl. Ph.D. thesis, Cornell Univ., Ithaca, NY. Dunham, D.W. 1965. Territorial and sexual behaviour in the Rose-breasted Gros- beak, Pheucticus ludouicianus. Z. Tierpsychol. 22:438-451. Finley, W.L. 1907. American birds studied and photographed from life. Scribner & Sons, New York. Head, A. 1902. A study of the Black-headed Grosbeak. Condor 4:119-121. Head, A. 1904. Nesting habits of the Black-headed Grosbeak. Condor 6:35-37. Ivor, H.R. 1944a. Bird study and some semi-captive birds: the Rose-breasted Grosbeak. Wilson Bull. 56:91-104. Ivor, H.R. 1944b. Rose-breasted Grosbeak in semi-captivity. Aviculture 14:179-182. Ritchison, G. 1983. The function of singing in female Black-headed Grosbeaks: fam- ily-group maintenance. Auk 100:105-116. Watts, G.E. 1935. Life history of the Rose-breasted Grosbeak. M.S. thesis, Cornell Univ., Ithaca, NY. Weston, J.G., Jr. 1947. Breeding behavior of the Black-headed Grosbeak. Condor 49:54-73. Accepted 6 September 1982 Black- headed Grosbeak Sketch by Tim Manolis 167 NOTE ALBINISTIC RED-BREASTED SAPSUCKER ROGER D. HARRIS, Department of Forestry and Resource Management, University of California, Berkeley, California 94720 On 5 July 1982 I photographed and observed an albinistic Red-breasted Sapsucker (Sphi/rapicus ruber) for 20 min, 200 m east of the dam on Lake Almanor, Plumas County, California, elevation 1380 m. Gross (Bird-banding 36:67-71, 1965) reported 48 records of albinism among 10 species (and subspecies) in the family Picidae, although he did not indicate whether any were Sph^jrapicus. 1 am not aware of any previous records of albinism for this species. The bird was a juvenile with all-white plumage except for a faint red-orange cap. Carotenoid pigments, which produce reds, oranges and yellows, are resistant to albinism (Sage, Brit. Birds 55:201-225, 1962). Typical of albino birds, legs and bill were ivory-colored, and eyes were bright pink. A normally pigmented sibling accompanied the albino and repeatedly pecked at it. The albino did not peck back. Nero (Auk 71:137-155, 1954) noted albino birds being harassed by conspecifics. Both recently fledged sapsuckers called constantly to at least one normally pigmented adult, which attended them approximately equally. I approached to within a meter of the albinistic bird before it flushed. It had a weak flight and repeatedly landed on small branches, where it would lose its balance and then hang upside-down for 5 to 10 s before flying again. The normally pigmented sib- ling had a stronger flight and flew past small branches to land directly and exclusively on tree trunks. Presumably the albino had defective eyesight as it landed on small branches more often than on tree trunks. Defective eyesight has been noted for albino birds (Mcllhenny, J. Heredity 41:433-438, 1940; Lincoln, Auk 75:220-221, 1958). I thank Daniel A. Airola, Ned K. Johnson and Michael L. Morrison for reviewing this note and Meryl Q. Sundove for assisting in the field. Accepted 20 August 1983 168 Western Birds: 14:168. 1983 Volume 14» Number 3» 1983 A Eurasian Skylark at Point Reyes, California, with Notes on Skylark Identification and Systematics Joseph Morion and Richard A. Erickson 113 Sixth Report of the California Bird Records Committee Laurence C. Binford 127 Nesting Ecology of Scrub Jays in Chico, California Lifman V. Ritter 147 Breeding Biology of the Black-headed Grosbeak in Northern Utah Gary Ritchison 159 NOTE Albinistic Red-breasted Sapsucker Roger D. Harris 168 Cover photo by Kenneth W. Fink: Horned Puffin (Fratercula corniculata) , 13 June 1982, St. Paul Island, Alaska Manuscripts should be sent to Alan M. Craig, P.O. Box 254, Lakeview, CA 92353. 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If this is not possible, extra charges for typesetting will be made as follows: $15 full page, $10 half page, $5 quarter page. Send copy with remittance to Garth Alton, 17 Camino Lenada, Orinda, CA 94563. Make checks payable to Western Field Ornithologists. A 15% commission is allowed for agencies. WESTERN BIRDS Volume 14, Number 4, 1983 MARIN COUNTY CALIFORNIA HERON COLONIES: 1967-1981 HELEN M. PRATT, Point Reyes Bird Observatory, 4990 Shoreline Highway, Stinson Beach, California 94970 Like all birds dependent on freshwater and marine wetlands, members of the heron family are suffering progressive loss of essential habitat. In addition, agricultural and industrial pollution threatens their capacity to reproduce. Great Blue Herons {Ardea herodias) and Black-crowned Night-Herons (Nyc- ticorax ni^cticorax) have declined in parts of their range and have been placed on the National Audubon Society’s Blue List of species “which have recently given or are currently giving indications of non-cyclical population declines or range contractions either locally or widespread” (Tate 1981). Most herons nest in conspicuous, often widely separated colonies. Some colony sites are used repeatedly for many consecutive nesting seasons; others are deserted after a few years and new colonies are established elsewhere. Sites are sometimes reoccupied after several years of inactivity and the number of birds may increase or decrease dramatically. Evaluation of popula- tion trends requires knowledge of both the history of active and inactive col- onies within a region and the population changes in individual colonies. This paper presents data on the location, population level, and history of 11 heron colonies known to have been occupied between 1967 and 1981 in Marin County, California (Figure 1). Its purpose is to provide a baseline for future comparisons by indicating current and past status. Marin County lies between approximately latitudes 37° 50 ' and 38° 20 ' N, and longitudes 122° 28 ' and 123° 00 ' W. It borders the Pacific Ocean on the west and San Francisco Bay on the south and east. It is rich in tide flats and estuaries suitable for foraging herons and egrets. That Grinnell and Miller (1944) listed no Great Blue Heron colonies in Marin County as of 1943 is probably because ornithologists were not as familiar with the area as they are today. One Marin County heronry is known to have been occupied since at least 1941; the other sites are of more recent or intermittent occupancy. Western Birds 14: 169-184, 1983 169 MARIN COUNTY HERON COLONIES 170 Figure 1. Locations of Marin County, California, heron colonies. 1. Audubon Canyon Ranch, 2. Da Silva Island. 3. Home Bay, 4. Inverness Park, 5. Nick’s Cove, 6. North San Pedro Road, 7. Olema, 8. Sand Point, 9. Schooner Bay A, 10. Schooner Bay B, 11. Stafford Lake, 12. West Marin Island. MARIN COUNTY HERON COLONIES The species nesting in Marin County include the Great Blue Heron, Great Egret (Casmerodius albus), Snowy Egret (Egretta thula), and Black-crowned Night-Heron. Great Blue Herons nest at 10 colonies, Great Egrets 5 colonies, and Snowy Egrets and Black-crowned Night-Herons only 1 colony. METHODS Estimates for the number of breeding pairs at nine colonies were based on total active nests. Counts were made with binoculars and spotting scopes from hillsides near colonies where it was possible to determine whether or not nests were active. Nest counts were made by the author except as otherwise noted. I estimated the size of the Inverness Park colony from nest counts augmented by reports from other observers of the number of flying herons seen early in the season. At the West Marin Island Colony the estimates for 1965, 1979 and 1981 were of occupied nests. I also include counts from 1973 through 1981 of the maximum number of birds seen on or feeding near the island. These counts were made from shore with a spotting scope at a distance of ap- proximately 1.2 km with only one side of the island visible. They may be com- pared with each other to indicate population trends but do not provide an estimate of the number of occupied nests. COLONY DESCRIPTIONS AND HISTORIES AUDUBON CANYON RANCH Audubon Canyon Ranch (Figure 2) is a wildlife sanctuary and nature education center located on Shoreline Highway about 5.8 km north of Stin- son Beach on the east side of Bolinas Lagoon (Figure 1) . Great Blue Herons and Great Egrets nest here in Coast Redwoods {Sequoia semperuirens) . In 1969 about five pairs of Snowy Egrets also nested in the colony. It is impossible to date the establishment of this colony, but since the trees at Audubon Canyon Ranch were cut during heavy logging that started in western Marin County in 1849 (Mason and Barfield 1973) and the nests are in second growth, it probably does not predate the late 1800s. M. Galloway (pers. comm ), a former resident of the ranch, reports that the colony was well-established and active in 1941 and included both Great Blue Herons and Great Egrets. Although Great Egrets were known to breed in the San Joaquin Valley in the 1920s (Moffitt 1939), the first recorded observation of a Great Egret in the San Francisco Bay region between the time when they were almost extirpated by plume hunters in the 1880s and their reappearance after being protected, was in October 1924 (Stoner 1934). Stoner (1934) also reported an observation of seven Great Egrets at Bolinas on 7 May 1929. Bolinas is 5 km from Audubon Canyon Ranch on the opposite side of Bolinas Lagoon and egrets currently sighted there at that time of year are known to be from the Audubon Canyon Ranch breeding population. Because the Great Egret population is usually at its maximum during May, the egrets reported in 1929 probably were breeding at Audubon Canyon Ranch. Great Egrets have joined established Great Blue Heron colonies at other sites in Marin County (see below), and they might well have done the same here. From 1967 through 1981 the Great Blue Heron population ranged from 27 to 62 breeding pairs with a declining trend since 1973 (Table 1) . The Great 171 MARIN COUNTY HERON COLONIES Egret population increased during the same period from 70 pairs to 148 (Table 2). Details of nesting success for 1967 through 1973 have been published previously (Pratt 1970, 1972a, 1972b, 1974). DA SILVA ISLAND The Da Silva Island colony is on the south side of a hill known as Da Silva Island, which borders Richardson Bay at the north end of the Richardson Bay bridge in Mill Valley (Figure 1). The hill is approximately 95 m from U.S. Highway 101, and though not an island now, may have been one before development of the area. It is privately owned and there are several dwellings close to the colony. Great Blue Herons nest here in Eucalyptus sp. The colony was first oc- cupied in 1979 by five pairs and was occupied again in 1980 and 1981 (Table 1) . HOME BAY Great Blue Herons nested in live oaks (Quercus sp.) on the northwest side of the south finger of Home Bay, a branch of Drake’s Estero in the Point Reyes National Seashore (Figure 1), in 1968 and 1969 (Table 1). There are no reports for 1970-1978. In 1979 there was an unverified report of two or three nests. I was unable to find nests there in 1980 but found one in 1981. INVERNESS PARK This colony is on private land in a clump of Douglas-fir (Pseudotsuga wen- ziesii) (Figure 3) growing at the edge of Sir Francis Drake Boulevard 2 km south of Inverness (Figure 1) . It was first reported occupied by Great Blue Herons in 1972 by the resident of a house opposite the colony. It may have been inactive in 1973 but was occupied again at least by 1975, the year that Great Egrets first nested there. Estimates of breeding pairs are highly tentative Table 1. Numbers of breeding pairs of Great Blue Herons at Marin County colonies from 1967 through 1981. Dashes indicate known absence of birds. U= Nest counts unavailable; herons may or may not have been nesting. 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 Audubon Canyon 50 62 55 50 44 46 58 48 45 40 41 43 35 33 27 Da Silva Island _______ — — ___5 5 3 Home Bay U2a3«UUUUUUUUUU-l Inverness Park UUUUU16-U4343U12 8 Nick’s Cove U U U 23« U U U 23 28 23 24 16^ U 18 15 No. San Pedro Rd. - -- -111--12 1443 Olema U U U26«U19b - -- -- -- -- Sand Point UUUUUUU 25 7 UUUUU16 Schooner BayA&BU U U U U U 15 15 12 9 - 7 7 7 3 Stafford Lake U U 5a U U 5^ 14 21 U 21 19 16 27 23 aCalifornia Dep. of Fish & Game, unpubl. data bRichard Brown (pers. comm.) Alice Williams (pers. comm.) 172 MARIN COUNTY HERON COLONIES Figure 2. Audubon Canyon Ranch. Egrets are visible occupying nests in trees behind the ranch house. Photo by Clerin Zumwalt 173 MARIN COUNTY HERON COLONIES because the nests are unusually difficult to find. The Great Blue Heron population has probably been as high as 16 pairs and as low as 4 (Table 1). There have been as many as 12 Great Egret pairs but usually fewer (Table 2) . NICK’S COVE This colony is on private land in a eucalyptus grove about 0.5 km east of Nick’s Cove on Tomales Bay (Figure 1). 1 have no records prior to 1970, when the colony contained 23 Great Blue Heron nests, but it had likely been occupied before that date. Great Egrets nested there in 1974, with five nests, probably for the first time. Their late arrival that year (early June compared with late April in 1975 and 1976) suggests that they moved to Nick’s Cove after experiencing nesting failure at another colony. The Great Blue Heron population has remained fairly stable (Table 1). The Great Egret nest count has fluctuated between 5 and 15 (Table 2). NORTH SAN PEDRO ROAD The North San Pedro Road colony (Figure 4) is on private property at the edge of San Pablo Bay about 3 km southeast of the Marin County Civic Center (Figure 1) . Great Blue Herons nest here in live oaks and Madrone {Ar- butus menziesii) . One heron pair nested here for the first time in 1971 (L. Boyd pers. comm.). Except for 1974 and 1975, when no herons return- ed, there were between one and four nests through 1981 (Table 1). OLEMA This colony was located in the Point Reyes National Seashore in Douglas- firs about 1.5 km northwest of the Seashore Headquarters at Olema (Figure 1) . The colony had 26 Great Blue Heron nests in 1970 and 19 in 1972 but has been inactive since then. SAND POINT The Sand Point colony is on private land on the east side of Tomales Bay between Sand Point and Tom’s Point about 2 km southeast of Dillon’s Beach (Figure 1) . Great Blue Herons and Great Egrets nest here in eucalyptus trees. Herons have occupied the colony since at least 1974 (Table 1) and the egrets joined them sometime between 1976 and 1981 (Table 2). Table 2. Numbers of breeding pairs of Great Egrets at four Marin County colonies from 1967 through 1981. Dashes indicate known absence of birds. U= Nest counts unavailable; egrets may or may not have been nesting. 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 Audubon Canyon 70 74 86 85 85 96 99 96 85 65 84 88 98 103 148 Inverness Park — — — — — — — — 3 4 12 2 U 1 — Nick’s Cove U U U — U U U 5 15 13 6 12^ U 6 5 Sand Point u u u U U U U — — U U U U U 6 a California Dep. of Fish & Game, unpubl, data 174 MARIN COUNTY HERON COLONIES Figure 3. Inverness Park heronry. Photo by Helen M. Pratt Figure 4. North San Pedro Road heronry. Nests were in the trees behind and to right of the large tree in left foreground. Photo by Helen M. Pratt 175 MARIN COUNTY HERON COLONIES SCHOONER BAY A AND B The Schooner Bay A colony is about 0.5 km south of Sir Francis Drake Boulevard behind the dwellings at the Johnson Oyster Company on the northeast shore of Schooner Bay, a branch of Drake’s Estero in the Point Reyes National Seashore (Figure 1) . Great Blue Herons nest here in eucalyp- tus trees. This colony was first occupied in 1963 (C. Johnson pers. comm.) and except for 1977 has been active every year through 1981 (Table 1). The Schooner Bay B colony (Figure 5) was first reported to me in 1981 (D. Shuford pers. comm.) . It is directly across the bay within 0.5 km of Schooner Bay A. Of the five nests in 1981 , two were successful Great Blue Heron nests. The other three were unoccupied at the time of my 24 June visit and showed no signs of heron occupancy such as splash or eggshells on the ground. They may have failed early or were built the year before but not used in 1981. The Schooner Bay sites are so close together that I currently consider them to be one split colony. STAFFORD LAKE This colony (Figure 6) is on the island in Stafford Lake about 4.5 km west of Novato on South Novato Boulevard (Figure 1). The lake and island are owned by the North Marin Water District. Great Blue Herons nest here in live oak and California Bay (Umbellularia californica) . They first nested here in 1962 (W.H. Melson pers. comm.) and the colony has become one of the three largest Great Blue Heron colonies in the county (Table 1). Figure 5. Schooner Bay B. The heron nests were in the small grove of trees on the far side of the bay. Photo by Helen M. Pratt 176 MARIN COUNTY HERON COLONIES Figure 6. Stafford Lake heronry. The nests were concentrated in trees on the left third of the island. Photo by Ian Tait Figure 7. West Marin Island heronry. Photo by Ian Tait 111 MARIN COUNTY HERON COLONIES WEST MARIN ISLAND West Marin Island (Figure 7) is one of a pair of small privately-owned islands in San Francisco Bay about 1.5 km offshore from Loch Lomond Yacht Har- bor in San Rafael (Figure 1). Great Egrets, Snowy Egrets and Black-crowned Night-Herons nest here in California Buckeye (Aesculus californica) , live oak and coastal scrub. This site was not mentioned by Grinnel and Miller (1944) but it was active in 1957 and had been “growing for many years” (Ralph and Ralph 1958). Stoner (1934) reported occurrences in the early 1930s of Great Egrets on the southern and eastern shores of San Francisco Bay but none north of the Golden Gate. Judging by this report Great Egrets did not colonize West Marin Island until at least the late 1930s or early 1940s. Snowy Egrets, like Great Egrets, were almost wiped out by plume hunters and were thought to be extinct in California by 1900, but by 1908 they were being recorded again and in 1943 were considered fairly common in suitable habitat (Grinnell and Miller 1944). They had been nesting on West Marin Island for at least 5 years in 1957 (Ralph and Ralph 1958) . At that time it was the northernmost breeding site for Snowy Egrets in California. Black-crowned Night-Herons could have been nesting unobserved on West Marin Island before either of the egrets arrived. Grinnell and Miller (1944) described them as “varyingly common almost throughout (the) state.” There was a colony of Black-crowned Night-Herons on Belvedere Island in 1938 (Moffitt 1939) but development forced them to move . They may have gone to West Marin Island, perhaps joining an established colony. In 1957 Ralph and Ralph (1958) estimated that there were 1000 Great Egrets, 400 Snowy Egrets and 600 Black-crowned Night-Herons on the island. Although not stated, this estimate probably included both adults and young. According to an unpublished California Department of Fish and Table 3. Maximum numbers of individuals of Great Egrets, Snowy Egrets and Black- crowned Night-Herons seen on or feeding near West Marin Island from 1973 through 1981. Data provided by Rosamund Day. Great Egret Snowy Egret Black-crowned Night-Heron 1973 125 418 105 1974 148 674 30 1975 139 332 140 1976 116 369 125 1977 115 315 70 1978 136 874 67 1979 120 494 98 1980 135 570 90 1981 168 640 62 178 MARIN COUNTY HERON COLONIES Game report (Anon. 1965), the colony contained 100 Great Egret, 25 Snowy Egret and 100 Black-crowned Night-Heron nests in 1965 but it had been inactive for several years prior to that date. My estimates made from a boat circling the island in May 1979 were 58 Great Egret, 262 Snowy Egret and 98 Black-crowned Night-Heron nests. On a similar survey on 20 June 1981, 1 estimated 75 Great Egret, 325 Snowy Egret and 109 Black-crowned Night-Heron nests. Table 3 shows counts made from 1973 through 1981 of maximum numbers of individuals, including both adults and fledged young, seen on or feeding near the island. Counts for all three species varied during this period without showing clear trends. An adult Little Blue Heron {Egretta caerulea) was seen on West Marin Island in August 1965 (Chase and Paxton 1966). Nesting was suspected but not confirmed. Dead young first identified as Little Blue Herons were later found to be Snowy Egrets (Unitt 1977) . I know of no subsequent reports of Little Blue Herons nesting there. On 4 July 1981 fire burned the nesting substrate over about 1.5 acres of the northwest slope of the island. An estimated 100 young Snowy Egrets and Black-crowned Night-Herons died. The Great Egret nests were apparently spared. At this writing the consequences for the 1982 nesting season are unknown. DISCUSSION Heron colonies are characterized by wide variations in population levels from year to year. (e.g. Thompson and Littlefield 1980) . The fluctuations are far in excess of what could be explained by mortality or variations in breeding success and are probably the result of shifts of breeding birds from one colony to another. In addition, Marin County heron populations are not necessarily self-contained but probably intermingle with those of other nearby counties in the San Francisco Bay region. The counts in Marin County, therefore, may not be indicative of more generalized trends and should be interpreted with caution. The largest Marin County Great Blue Heron colony, Audubon Canyon Ranch has shown a declining population trend since 1974. The Schooner Bay colony has also decreased in size but the Stafford Lake and Inverness Park colonies have increased (Table 1). Two small new colonies were established at North San Pedro Road and Da Silva Island. It is difficult to draw conclusions about Marin County Great Blue Heron population trends because accurate nest counts at Inverness Park and Sand Point were not available for most years, but there has been no general decline. The California Department of Fish and Game statewide surveys of heron colonies taken in 1969, 1970, 1971, 1972 and 1978 show a steady increase in active Great Blue Heron nests that is believed to be both the result of discovery of more col- onies and an indication of population increase (Belluomini 1978) . The Great Egret breeding population increased at Audubon Canyon Ranch from 1967 through 1981 and the egrets appeared in three colonies where they had not nested previously (Table 2). Great Egrets have clearly declined on West Marin Island since the count of 1000 individuals in 1957 (Ralph and 179 MARIN COUNTY HERON COLONIES Ralph 1958), and the nest estimates of 58 in 1979 and 75 in 1981 show a decline from the 1965 level of 100. Counts of egrets seen around the island since 1974 (Table 3) suggest that in spite of yearly fluctuations the population has recently been fairly stable. The California Fish and Game surveys show an increase statewide in the number of Great Egret nests from 401 in 1969 to 853 in 1978 (Belluomini 1978). The Snowy Egret population on West Marin Island increased from 25 nests in 1965 to 325 in 1981. Comparing nest counts with the 1957 (Ralph and Ralph 1958) count of 400 individuals (adult and young) is risky, but assuming an average of two young/nest, the 1979 and 1981 counts would represent 524 and 650 young respectively augmented by an undetermined number of adults attending nests. Thus it would appear that Snowy Egrets have increas- ed on West Marin Island over the 1957 levels as well. The statewide count of Snowy Egret nests increased from 227 in 1969 to 3704 in 1978 primarily because a new colony that contained 2500 nests was discovered at the north end of the Salton Sea in 1978 (Belluomini 1978) . Black-crowned Night-Herons have probably decreased in numbers on West Marin Island since 1957 when Ralph and Ralph (1958) estimated 600 birds (adults and young) . The California Fish and Game estimate of 100 nests in 1965 and my estimates of 98 nests in 1979 and 109 in 1981 suggest a recently stable population. The statewide survey of nests shows a small decrease from a maximum of 1225 in 1971 to 939 in 1978 (Belluomini 1978). Nests in four of the Marin County colonies are built in Eucalj^ptus, non- native trees introduced to California from Australia in the late 1800s. They grow to heights exceeding 100 m and occur in small groves where there are often no tall native trees. They thus afford suitable nest sites for herons in areas where native trees do not. One can only speculate about how the introduction of Eucali;ptus may have affected the heron population and distribution of col- onies. Perhaps colonies are more scattered, smaller and closer to certain estuarine feeding grounds. Perhaps Eucal^^ptus trees provide alternate sites for colonies that were displaced by logging in the past. The addition of. Eucalyptus to the California flora seems unlikely to have been instrumental in increasing heron and egret populations. Note that only three of the colonies active in 1981 — Audubon Canyon Ranch, Schooner Bay and Stafford Lake — are on land protected from development. The remainder including West Marin Island, the largest colony and currently the only known nesting site in Marin County for Snowy Egrets and Black-crowned Night-Herons, are privately owned. That the colonies on private land will remain undisturbed indefinitely cannot be assumed . Develop- ment is already planned for Da Silva Island, although the nest trees will not be cut. Herons and egrets are limited to nest sites that are near aquatic feeding grounds, such as estuaries or takes, and that are in inaccessible locations, such as islands, marshes or high in tall trees, where they are protected from ground predators. When current sites become unsuitable through destruction or ex- cessive disturbance, the presence of alternative sites becomes important. Periodic regional surveys of heron colonies should be continued to determine the status of populations and to assess the nesting and feeding resources for these birds as pressures from development increase. 180 MARIN COUNTY HERON COLONIES ACKNOWLEDGMENTS I thank the many people who helped during the nesting seasons at Audubon Canyon Ranch. Most have been acknowledged elsewhere. I also thank Elizabeth Meyers who helped at Schooner Bay, Pamela Williams who censused at Nick’s Cove and Karen Schwartz who helped at Audubon Canyon Ranch. Philip Schaeffer, Jean Starkweather, Rosamund Day, Alan Ruppert, Meryl Sundove and David Holway assisted in the West Marin Island counts. David Shuford, David DeSante and Laurence Binford made con- structive comments on an earlier draft of the manuscript. William Thomson provided unpublished California Department of Fish and Game reports. Guy McCaskie provided data on the Little Blue Heron record at West Marin Island. This is Point Reyes Bird Observatory Contribution 241. LITERATURE CITED Anonymous. 1965. Untitled. Unpubl. rep. California Dep. Fish & Game, Sacramento. Belluomini, L.A. 1978. Statewide heron rookery inventory. California Dep. Fish & Game, Sacramento. Chase, T. & R.O. Paxton. 1966. The fall migration. Middle Pacific coast region. Aud. Field Notes 20:87-88. Grinnell, J. & A.H. Miller. 1944. The distribution of the birds of California. Pac. Coast Avif. 27. Mason, J. &T.J. Barfield. 1973. Last stage for Bolinas. North Shore Books, Inverness, CA. Moffitt, J. 1939. Notes on the distribution of herons in California. Condor 41:81-82. Pratt, H.M. 1970. Breeding biology of Great Blue Herons and Common Egrets in cen- tral California. Condor 72:407-416. 1972a. Nesting success of Common Egrets and Great Blue Herons in the San Francisco Bay region. Condor 74:447-453. 1972b. Nesting success of Great Blue Herons and Common Egrets at Audubon Canyon Ranch in 1971. Am. Birds 26:699-702. 1974. Breeding of Great Blue Herons and Great Egrets at Audubon Canyon Ranch, California, 1972-1973. West. Birds 5: 127-136. Ralph, C.J. & C.L. Ralph. 1958. Notes on the nesting of egrets near San Rafael, California. Condor 60:70-71. Stoner, E.A. 1934. Recent occurrences of the American Egret in the San Francisco Bay region. Condor 36:57-59. Tate, J., Jr. 1981. The Blue List for 1981. Am. Birds 35:3-10. Thompson, S.P. & C.D. Littlefield. 1980. Historical review and status of colonially nesting birds on Malheur National Wildlife Refuge, Oregon. Proc. 1979 Conf. Colonial Waterbird Group 3:156-164. Unitt, P. 1977. The Little Blue Heron in California. West. Birds 8:151-154. 181 MARIN COUNTY HERON COLONIES ADDENDUM The fire on 4 July 1981 on West Marin Island apparently did not affect Great Egret or Snowy Egret breeding there in 1982. The Great Egret nests in- creased to 187 and the Snowy Egret nests increased to 500 in 1982. The Black-crowned Night-Heron nests, however, decreased to 80 in 1982 from 109 in 1981. It is possible, though not proven, that the fire discouraged some night-heron pairs from returning to the island in 1982. In 1982 two previously unknown Great Blue Heron colonies were discovered in Marin County (D. Shuford pers. comm.). One containing six nests was in a fir tree on the south shore of Lake Nicasio. The other containing 11 nests was in Eucal^/ptus trees on the east side of Drake’s Head, a promon- tory reaching into Limantour Estero, the estuary extending eastward from the mouth of Drake’s Estero. People rarely pass near these colonies and they have probably been active but undetected for several years. Accepted 25 March 1 983 182 Great Egret Sketch by Narca Moore-Craig MARIN COUNTY HERON COLONIES Great Egrets during pair formation. Photo by Philip Greene 183 MARIN COUNTY HERON COLONIES Great Blue Heron presenting a twig to its mate. Photo by Philip Greene 184 STATUS OF THE HERMIT WARBLER IN WASHINGTON CHRISTOPHER B. CHAPPELL. 10101 Laurelcrest Lane S.W., Tacoma, Washing- ton 98498 BRENDA J. RINGER, Department of Biological Sciences. University of Idaho. Moscow, Idaho 83843 The Hermit Warbler (Dendroica occidentalis) reaches the northern limit of its breeding range in Washington, where its status has been unclear. The Hermit Warbler frequents treetops where it is difficult to observe, and its song resembles those of the Black-throated Gray Warbler (D. nigrescens) and Townsend’s Warbler (D. townsendi) . Other than a few references to a preference for tall conifers (Bowles 1906, Dawson and Bowles 1909, Rathbun 1916), mature coniferous forests (Rough 1957), and moderately dense coniferous forests (Cogswell 1957), little was known of its habitat requirements. The few scattered records of Hermit Warblers in Washington prior to 1970 provided little indication of its status, and most authors classi- fied it as uncommon in coniferous forests of western Washington. In the 1970s the number of records increased substantially as the number of field observers increased. Consequently. Wahl and Paulson (1977) con- cluded that the Hermit Warbler’s principal range in Washington was the southern Cascade Range and that it was common in that area. However, its status in other parts of the state and its specific habitat requirements were still uncertain. The purpose of this study was to delineate Hermit Warbler habitat requirements and to synthesize existing information on its distribution and abundance in Washington. METHODS Information on distribution and abundance of the Hermit Warbler was derived from the literature, the regional editor’s files of American Birds (AB files), the Washington Department of Game Data Storage and Retrieval System (WDG). personal interviews with knowledgeable people, and field work conducted as part of this study. During May and June 1979 we searched for Hermit Warblers in several areas of western Washington where its status was unknown, but its presence seemed likely. Appropriate habitats were surveyed by driving roads and frequently stopping to listen for Hermit Warblers: searches were also made along several hiking trails. Due to the variability and overlap in songs of Townsend’s and Hermit warblers, many of the warblers we heard, but did not see. were not identi- fied. Those that we did identify by sound only were separated by their song endings. Hermit Warbler songs often end with two abrupt, low-pitched notes. All of the many warblers in the southern Cascades that we were able to Western Birds 14: 185-196, 1983 185 HERMIT WARBLER IN WASHINGTON visually identify while they sang the low-pitched ending were Hermit Warblers. So, in the southern Cascades we used the low-pitched ending as our sole means of distinguishing them by sound. In areas outside of their principal range in the southern Cascades (see Figure 1), identification by sound alone is questionable and all of our listed records are of birds identified by sight. An intensive habitat survey was conducted in the southern Cascades of Washington. The object was to find how many different forest types sup- ported territorial Hermit Warblers and to analyze habitat characteristics of representative stands. During June 1979 we drove 30 km of roads in the St. Helens and Randle ranger districts in Skamania, Lewis and Cowlitz counties, in a search for Hermit Warbler habitat. We stopped at arbitrary points along roads in all forest types and listened for singing Hermit Warblers. We col- lected data on habitat characteristics in each of 13 representative stands where we found two or more singing Hermit Warblers. Tree species composition in each stand was quantified using the point- centered quarter method (Cottam and Curtis 1956) with points spaced at 5 m intervals along five 50 m transects. Transects generally ran parallel except where terrain prohibited. Cover in the shrub layer was measured along each transect using the line-intercept method (Cottam et al. 1953). Canopy closure was determined by the percentage of points at which the canopy occupied more than 50% of the area directly above each transect point. Elevation, aspect of slope, mean canopy height and stand age were also determined for each stand. Tree species composition of the stands was analyzed by a two axis ordina- tion (Mueller-Dombois and Ellenburg 1974) calculated from species import- ance values representing the sum of the relative density, dominance and fre- quency values of each tree species. This ordination graphically emphasized differences among stands in tree species composition (correlation coefficient = 0.834). DISTRIBUTION AND ABUNDANCE Figure 1 illustrates the known distribution of the Hermit Warbler in Washington. All localities mentioned in the following regional review of its past and present distribution and abundance are represented in Figure 1. OLYMPIC PENINSULA. Very few records exist prior to the 1970s, possibly because of a lack of ornithological investigation in the region. Rathbun (1916) regularly found singing Hermit Warblers during the breeding season in the Lake Crescent area, Clallam County, but considered the species uncommon. Hermit Warblers were found during the breeding season at the Quillayute Prairie, Clallam County, (Jewett et al. 1953), but dates and abundance were not reported. A single bird seen on Hurricane Ridge, 186 HERMIT WARBLER IN WASHINGTON 187 Figure 1. Known distribution of the Hermit Warbler in Washington. Dark lines separate regions: A = Olympic Peninsula; B = Puget Sound Trough; C = Southwest Washington; D = West slope of southern Cascades; E = West slope of northern Cascades; F = Eastern Washington. Shaded area represents principal range where the Hermit Warbler is widespread; A = historical record (before 1960); U = recent (after 1960) probable breeding site (male on territory during breeding season, i.e., June-early July); # = recent record (probably nonbreeding) . HERMIT WARBLER IN WASHINGTON Clallam County, on 13 July 1974 (AB files) fits the pattern of late summer up-mountain movements noted by Cogswell (1957). Three singing males were seen at Staircase on Lake Cushman, Mason County, on 9 June 1977 (AB 31:1182, 1977). Jewett et al. (1953) also indicated that Lake Cushman was a breeding season locality. Two singing males were seen at Lena Lake in the Hamma Hamma River drainage, Jefferson County, on 16 June 1978 (pers. obs.). During this study singing males were seen in the Dosewallips River Valley and near Mt. Jupiter, Jefferson County, on 28 May and 10 June 1979. Based on the recent increase in observers and sightings in the region, the Hermit Warbler appears to be a fairly common breeder on the east slope of the Olympic Mountains and to be less common (probably rare) in other areas of the Olympic Peninsula. Future investigations may reveal a few warblers at other localities on the peninsula. PUGET SOUND TROUGH. The warbler’s historical status in Washington was well documented at only one location: the South Tacoma-Spanaway area of Pierce County. According to Bowles (1906, 1929) , it was common in the stretches of fir woods in this prairie country from 1899 to 1921. Bowles (1929) noted a steady population decline from 1921 to 1929. Since then, the Hermit Warbler has been less common, but still present until recently. The most recent breeding record from Spanaway was 1966, and the last sighting was on 1 June 1974 (AB files). During May and June 1979, 2 days were spent searching for Hermit Warblers at Spanaway and adjacent Fort Lewis, but none were found. Jewett et al. (1953) listed Tenino, Thurston County, and Shelton, Mason County, as breeding season localities. Both areas exhibit a forest /prairie mosaic similar to that at Spanaway. For some unknown reason the Hermit Warbler has disappeared from the southern Puget Sound prairie country. Wahl and Paulson (1977) mentioned historical records from Deception Pass, Skagit and Island counties. A bird was seen during migration on Lopez Island, San Juan County, in 1936 (WDG). Single birds were seen during migration in the Seattle area. King County, on three occasions: 12 April 1954 (AFN 8:326, 1954), 16 August 1955 (AFN 10:49, 1956), and 15 May 1975 (D. Paulson, pers. comm.). Hermit Warblers recently seen in the southeast Puget Sound area at Eld Inlet, Thurston County, on 23 August 1978 (AB files) and at Mason Lake, Mason County, on 25 July 1979 (WDG) were possibly migrants from the population that breeds on the eastern Olym- pic Peninsula. The sighting of two birds on Harstene Island, Mason County, on 12 June 1977 (AB 31:1182, 1977) indicated the possibility of a small breeding population, although the birds were more likely vagrants. A pair resided at Scenic Beach State Park, Kitsap County, from 10 May 1979 through the breeding season (WDG) . This location is just across Hood Canal from a breeding population on the Olympic Peninsula, and birds on the Kit- sap Peninsula possibly represented an expansion of the Olympic Peninsula 188 HERMIT WARBLER IN WASHINGTON population. A male at Bellingham, Whatcom County, on 16 May 1981 (J. Duemel pers. comm.) , was the northernmost record of which we are aware. Currently, the Hermit Warbler is a rare summer resident and occasional migrant in the Puget Sound Trough. SOUTHWEST WASHINGTON. Townsend (1837) first described the Her- mit Warbler from a specimen taken at Vancouver, Clark County, but there were no subsequent records from the area until 5 September 1965, when one was seen during migration at Leadbetter Point, Pacific County (AFN 20:86, 1966). Another was seen 17 June 1975 on the Long Beach Penin- sula, Pacific County (AB files), and possibly represented a vagrant. The single singing male seen during this study at Toledo, Lewis County, on 1 June 1979 may have been on its breeding grounds, but was probably a migrant. This inexplicable sighting prompted a search of the Willapa Hills, Pacific and Lewis counties, on 8-9 June 1979, but no Hermit Warblers were found. Hermit Warblers occur in the Coast Range of Oregon (Gabrielson and Jewett 1940, AB files) , but apparently are absent or rare in the Willapa Hills, the range that links the Coast Range and the Olympics. WEST SLOPE OF SOUTHERN CASCADES. From Randle and Pack- wood, Lewis County, south to the Columbia River, the Hermit Warbler is a common breeding bird (D. Fix pers. comm., B. Harrington-Tweit pers. comm., pers. obs,). As Wahl and Paulson (1977) noted, this is the warbler’s principal range in Washington (Figure 1). In June 1979 we heard several singing birds at three localities in the foothills of Cowlitz County; the Hermit Warbler may be a widespread breeder in the foothills west of its principal range. North of Randle and Packwood the Hermit Warbler is uncommon, and we discovered no records previous to 1970. At the Bald Hills, Thurston County, a single bird was seen on 9 May 1970 (WDG), and two singing males were seen on 6 June 1981 (pers. obs.). Two sightings of individual birds were made during late summer 1976 in Mt. Rainier National Park, Pierce County (WDG): near Crystal Lake on 25 July and at Longmire on 14 August. Another was seen along the West Fork White River, Pierce County, on 14 May 1977 (pers. obs.). The male seen 19 July 1978 at Reflection Lakes, Lewis County, in Mt. Rainier National Park (pers. obs.) was probably a post- breeding season up-mountain wanderer. Recent investigations in the Pack Forest near LaGrande, Pierce County (B. Harrington-Tweit pers. comm., WDG) , and Federation Forest State Park, King County (Wahl and Paulson 1977, B. Harrington-Tweit pers. comm.) , have shown the Hermit Warbler to be a fairly common and regular breeder at both localities. Possibly it is more widespread as a breeder in the Cascades of northern Lewis County, Pierce County and southern King County than these two known breeding sites in- dicate. 189 HERMIT WARBLER IN WASHINGTON WEST SLOPE OF NORTHERN CASCADES. During summer 1979, a number of Hermit Warblers were seen in the northern Cascade region, where none had previously been recorded. Two territorial males were seen during the latter half of June 1979 south of Darrington, Snohomish County (pers. obs.). Two males were also seen along the North Fork Snoqualmie River, King County, on 28 June 1979 (AB 33:892, 1979). “Numbers” were found at Otter Lake near Skykomish, King County, on 9 July 1979 (AB 33:892, 1979), One was seen west of Glacier Peak, Snohomish County, on 16 August 1979 (pers. obs.). The preponderance of sightings during 1979 was not due to a previous lack of observers, as the area has received con- siderable exploration, but could be attributed to an expansion of birds out of their principal breeding grounds further south. EASTERN WASHINGTON. Most of the possible Hermit Warbler breeding records east of the Cascade Crest came from around the turn of the century. Stehekin, Chelan County, and the Calispell Range and Newport, Pend Oreille County, were listed as breeding areas by Dawson and Bowles (1909), and Dawson (1897) collected a specimen near Stehekin. Jewett et al. (1953) also reported sightings at Stehekin in 1900 and at Calispell Lake in 1906. A bird was seen during migration at Lyle, Klickitat County, on 19 August 1918 (Jewett et al. 1953). LaFave (1955) saw six on Mt, Spokane, Spokane County, on 30 August 1954, Single birds were seen near Spokane, Spokane County, on 26 May 1964 (AB files); at Wenas Park, Yakima County, on 29 May 1971 (AB 25:774, 1971); on Swakane Wildlife Recreation Area, Chelan County, on 18 May 1972 (WDG); at Wenatchee, Chelan County, on 12 September 1972 (WDG); and at Ephrata, Grant County, on 14-15 May 1977 (AB 31:1027, 1977). These recent records of migrants suggest the possibility that a few still breed in the mountains of northeastern Washing- ton, The only recent possible breeding record was of a pair seen at Swauk Pass in the Wenatchee Mountains, Chelan County, on 15 June 1978 (WDG). The Hermit Warbler was apparently more abundant in the Pacific North- west during 1979 than in recent years. This conclusion was evidenced by (1) the comments from many observers in Oregon on the species’ unusually large numbers there (AB 33:892, 1979); (2) a noticeable expansion of birds into the northern Cascades of Washington; and (3) a few sightings in other areas of Washington where Hermit Warblers were not found before. Future field work will show whether this “good year” represents a single-season peak in abundance or the beginnings of a non-cyclic population increase and range expansion. 190 HERMIT WARBLER IN WASHINGTON HABITAT REQUIREMENTS During the 1979 breeding season Hermit Warblers occurred in two major forest zones: the Tsuga heterophylla (Western Hemlock) zone and the Abies amabilis (Pacific Silver Fir) zone. The Hermit Warbler apparently did not breed regularly in the only other forest zone on the study area, the Tsuga mertensiana (Mountain Hemlock) zone, as we were unable to find any in this zone and we failed to locate any breeding season reports from this zone in Washington. The T. heterophylla zone typically occurs in moist areas from sea level to 900 m in southern Washington (Franklin and Dyrness 1973). Major tree species in this zone are Douglas-fir (Pseudotsuga menziesii), Western Hemlock and Western Redcedar (Thuja plicata) (Franklin and Dyrness 1973). The A, amabilis zone lies between the temperate mesophytic T. heterophylla zone and the subalpine T. mertensiana zone, generally at eleva- tions of 900-1300 m in southern Washington (Franklin and Dyrness 1973). It is wetter and cooler than the T. heterophylla zone and warmer with less snow pack than the higher T. mertensiana zone. Major tree species are Pacific Silver Fir, Western Hemlock, Noble Fir (Abies procera), Grand Fir, Douglas-fir, Western Redcedar, Lodgepole Pine (Pinus contorta) and Western White Pine (Pinus monticola) (Franklin and Dyrness 1973). The ordination of Hermit Warbler habitats (Figure 2) illustrated the relative similarities and differences in tree species composition among the stands we analyzed. The ordination clearly segregated stands of the 7. heteroph^lla and A. amabilis zones (Figure 2). At low elevations we found an association of Western Hemlock and Douglas-fir that corresponded to the T. hetero- phiflla zone. Stands 10, 11 and 13 (Figure 2) were characteristic young serai communities dominated by Douglas-fir; stands 10 and 11 were 50-60 years old; and stand 13 was about 25 years old. Stands 2 and 12 were dominated by Western Hemlock and Douglas-fir, with hemlock the primary reproducing species under a canopy of mature (100-200 years) and old-growth (200-1- years) Douglas-fir. Stand 7 was an old-growth community dominated by Western Hemlock. Stand 9 was an old-growth riparian community dominated by Western Redcedar and Grand Fir. Western Hemlock was the major reproducing species under the canopy of all stands within the 7. heterophylla zone. The second major group of stands on the ordination corresponded to the A. amabilis zone (Figure 2). Stand 4 was a young community (35 years) dominated by Western Hemlock, Western Redcedar and Pacific Silver Fir. and was located in an area of transition between the 7. heterophiflla and A. amabilis zones. Stands 1 and 3 were dominated by old-growth Pacific Silver Fir and Western Hemlock. Stand 6 was a unique association of Pacific Silver Fir and Lodgepole Pine that resulted from the dry, infertile soils developed from prior volcanic activity of Mt. St. Helens (Franklin 1966). Stand 8 was dominated by old-growth Grand Fir and a younger component of Pacific 191 HERMIT WARBLER IN WASHINGTON Silver Fir, Stand 5 was an old-growth community dominated by Noble Fir and Pacific Silver Fir typical of cooler sites near the upper elevational limits of the A. amabilis zone. Pacific Silver Fir was dominant or codominant and was the major reproducing species in all stands within the A. amabilis zone. The ordination of 13 representative stands (Figure 2) indicated that Hermit Warblers were not specific in their habitat requirements, using a variety of coniferous forest associations within the T. heterophi^lla and A. amabilis zones. Forests used were dense (mean canopy closure 70%), except for the Lodgepole Pine community (Stand 6, canopy closure 6.5%). Mean canopy height ranged from 13.6 m to 42.6 m. Deciduous trees were frequently codominant in the understory or a minor component of the canopy, especially in young stands. Cover in the shrub layer ranged from 3% to 48% (mean 16%), and shrub species conformed to expected associations with canopy species. The shrub layer appeared to be an incidental factor in habitat requirements as Hermit Warblers foraged and sang mainly in the canopy or Figure 2, Community ordination of forest stands representing Hermit Warbler habitat in the southern Cascades of Washington. Numbers correspond to those used in the text. Forest zones; ★ = Tsuga heterophi>lla zone; 9 = Abies amabilis zone. Tree species; WH = Western Hemlock; SF = Pacific Silver Fir; GF = Grand Fir; NF = Noble Fir; DF = Douglas-fir; RC = Western Redcedar; LP = Lodgepole Pine, 192 HERMIT WARBLER IN WASHINGTON just below it. Aspect of slope also appeared to be an incidental factor in Her- mit Warbler habitat requirements. Stand age ranged from second-growth as young as 25 years to old-growth (200 -I- years) . Hermit Warblers appeared to be as numerous in young stands as in mature and old-growth stands, but this abundance in young stands may have been related to the apparent popula- tion increase of 1979. A study comparing population densities in various forest types (especially second-growth vs. old-growth) would be an appropri- ate follow-up to our study and would better define any management needs. The habitat requirements delineated for Hermit Warblers in the southern Cascades appeared to be a fairly accurate representation of the Hermit Warbler’s habitat use in other regions of Washington. West of the Cascade crest the Hermit Warbler breeds in various coniferous associations of the T. heterophi^Ila and A. amabilis zones. The Hermit Warbler apparently does not breed in the coastal Picea sitchensis (Sitka Spruce) zone nor the subalpine 7. mertensiana zone. However, there are two recent records (probably migrants) and one historical breeding season record from the coast (Figure 1), and there are several late summer records from the subalpine zone that fit the pattern of up-mountain movement after the breeding season noted by Cogswell (1957). The only recent possible breeding site east of the Cascade crest was an old-growth stand of Grand Fir and Douglas-fir in the Wenatchee Mountains (Figure 1). The Townsend’s Warbler is a very close relative of the Hermit Warbler, They have similar songs and habitat requirements, and their ranges overlap in the Cascade and Olympic mountains of Washington. Very little is currently known of the interactions between these two species that were frequently found breeding in close proximity to one another (B. Harrington-Tweit pers. comm., pers. obs.) and that have hybridized at least occasionally (Jewett 1944). Recently, hybrids have been found in Washington at the Pack Forest near LaGrande, Pierce County (B. Harrington-Tweit pers. comm.), and in Federation Forest State Park, King County (Wahl and Paulson 1977). The most distinct difference that we observed in the habitat preferences of the two species was that the Hermit Warbler occurred only in the low to middle elevation forests of the T. heterophyWa and A. amabilis zones, whereas the Townsend’s Warbler also occurred in the higher elevation subalpine forests of the 7 mertensiana zone. There is no apparent habitat or niche separation between the Hermit and Townsend’s warblers in areas where they both occur (B. Harrington-Tweit pers. comm., pers. obs.). This interspecific relationship raises many questions, some of which will hopefully be answered by future research. SUMMARY The Hermit Warbler is uncommon to rare over most of Washington State and its status has been unclear. The principal range of the Hermit Warbler in Washington is the west slopes of the southern Cascades where it is a corn- 193 HERMIT WARBLER IN WASHINGTON mon summer resident and breeder. The Hermit Warbler breeds uncom- monly further north on the west slopes of the Cascades in Pierce and southern King counties. Prior to 1979, the Hermit Warbler had not been recorded on the west slopes of the northern Cascades. During the summer of 1979 several sightings were made in the northern Cascades, indicating an expansion out of the usual breeding grounds further south, The Hermit Warbler has declined in numbers in the Puget Sound region since the early 1900s. It was formerly of regular occurrence in the forest/prairie mosaic of the southern Puget Sound region, but it is now rarely seen in that area. The Hermit Warbler is now a rare summer resident and occasional migrant in the Puget Sound region. Recently, it was discovered that the eastern slopes of the Olympic Mountains harbor a sizable population of Hermit Warblers; the species is a fairly common summer resident and probable breeder in the area. Hermit Warblers are rare east of the Cascade crest where there have been several recent records during migration and only one recent breeding season sighting. Available evidence indicated that Hermit Warblers were more abun- dant than usual in Oregon and Washington during 1979. Hermit Warblers in the southern Cascades of Washington used a variety of coniferous forest associations within the Tsuga heterophylla and Abies amabilis zones. None were found during the breeding season in the subalpine Tsuga mertensiana zone. Most forests used were moderately dense. Hermit Warblers occurred in second-growth forests (as young as 25 years) as well as in mature and old-growth forests. The closely related Townsend’s Warbler occasionally hybridizes with the Hermit Warbler and the two species often breed in close proximity to one another. The Townsend’s and Hermit warblers exhibited no observable habitat segregation. ACKNOWLEDGMENTS We would like to thank D. Hansen of Pacific Lutheran University for his assistance in preparing the ordination. Jim Duemel, David Fix, Bill Harrington-Tweit, Phillip W. Mattocks, Jr., Dennis R. Paulson and Terence R. Wahl generously provided invaluable information. Bill Harrington-Tweit, Robert L. Jarvis, Dennis R. Paulson and Terence R. Wahl critically reviewed various drafts of the manuscript and provided helpful suggestions. We are also grateful to Allison Duryee for her field assistance, Richard L. Knight for the idea that sparked the beginning of this study, Elizabeth A. Rodrick for allowing us time off when we needed it, and Linda Crooks and Susan Peter- son for their assistance in preparing the manuscript. Portions of this research were supported by the Nongame Program, Washington Department of Game. 194 HERMIT WARBLER IN WASHINGTON LITERATURE CITED Baldridge, A. & J.B. Crowell. 1966. The autumn migration. Northern Pacific Coast region. Aud. Field Notes 20:86. Bowles, J.H. 1906. The Hermit Warbler in Washington. Condor 8:40-42. Bowles, J.H. 1929. Changes in bird population. Murrelet 10:52-55. Cogswell, H.L. 1957. Hermit Warbler Dendroica occidentaiis. Pp. 144-146 in L. Griscom and A, Sprunt. The warblers of America. Devin-Adair Co., New York, Cottam, G. & J.T. Curtis. 1956. The use of distance measures in phytosociological sampling. Ecology 37:451-460. Cottom, G., J.T. Curtis & B.W. Hale, 1953. Some sampling characteristics of a pop- ulation of randomly dispersed individuals. Ecology 34:741-757. Dawson, W.L. 1897. A preliminary list of the birds of Okanogan County, Washing- ton. Auk 14:168-182. Dawson, W.L. 1910. Rouge et noir. Condor 12:170. Dawson, W.L. & J.H. Bowles. 1909. The birds of Washington. Occidental Publ. Co., Seattle, WA. Flahaut, M.R. & Z.M. Schultz. 1954. The spring migration. North Pacific Coast region. Aud. Field Notes 8:326. Flahaut, M.R. & Z.M, Schultz. 1956, The autumn migration. North Pacific Coast region. Aud. Field Notes 10:49. Franklin, J.F. 1966. Vegetation and soils in the subalpine forests of the southern Washington Cascade Range. Ph.D. thesis, Washington State Univ., Pullman. Franklin, J.F. & C.T. Dyrness. 1973. Natural vegetation of Oregon and Washington. USDA Forest Service Gen. Tech. Rep. PNW-8. Gabrielson, I.N. & S.G. Jewett. 1940. Birds of Oregon. Oregon State College, Corvallis. Harrington-Tweit, B., P.W. Mattocks, Jr. & E.S. Hunn. 1979. The nesting season. Northern Pacific Coast region. Am. Birds 33:892. Hunn, E.S. & P.W. Mattocks, Jr. 1977. The nesting season. Northern Pacific Coast region. Am. Birds 31:1182. Jewett, S.A., W.P. Taylor, W.T. Shaw & J.W. Aldrich. 1953. Birds of Washington State. Univ. Washington Press, Seattle. Jewett, S.G. 1944. Hybridization of Hermit and Townsend’s warblers. Condor 46:23-24. LaFave, L.D. 1955. Another sight record of the Hermit Warbler for eastern Washing- ton. Murrelet 36:11. Mueller-Dombois, D. & H. Ellenburg. 1974. Aims and methods of vegetation ecology. John Wiley & Sons, Inc., New York. Pough, R.H. 1957. Audubon western bird guide. Doubleday, Garden City, N.Y. Rathbun, S.F. 1916. The Lake Crescent region, Olympic Mountains, Washington, with notes regarding its avifauna. Auk 33:357-370. Rogers, T.H. 1971. The spring migration. Northern Rocky Mountain-intermountain region. Am. Birds 25:774, 195 HERMIT WARBLER IN WASHINGTON Rogers, T.H. 1977. The spring migration. Northern Rocky Mountain-intermountain region. Am. Birds 31:1027. Townsend, J.K. 1837. Description of twelve new species of birds, chiefly from the vicinity of the Columbia River. J. Acad. Nat. Sci. 7:187-193. Wahl, T.R. & D.R. Paulson. 1977. A guide to bird finding in Washington. T.R. Wahl, Bellingham, WA. Accepted 17 March 1982 Hermit Warbler Sketch by Cameron Barrows 196 REPORT TO MEMBERS TERENCE WAHL, President, Western Field Ornithologists WFO’s annual meeting was held in Santa Cruz, California, 29 September-2 October 1983. The meeting was co-hosted by the Santa Cruz Bird Club, whose members assisted the local committee. Debi Love Shear- water was convention organizer and did an outstanding job. Jerry Langham ably introduced speakers at the papers presentation which included Birding Santa Cruz County, Aging Jaegers, The Manx Shearwater Group, UCSC Predatory Bird Project, Farallon Islands Birds, and the Survey of Central and Northern California Seabirds: 1980-1983. The banquet speaker, Bruce Eilliott, brought home the need for people like WFO members to assist with management of nongame species by providing good and otherwise unavailable information. To the many people who made the meeting and field trips so successful and enjoyable. I’m sure over 100 persons who at- tended will add thanks to mine. Field outings included pelagic trips which featured the impressive flocks of storm-petrels and other birds and many marine mammals on Monterey Bay, land and water birds of the Santa Cruz area, and a cooperative Sharp-tailed Sandpiper hung-out long enough to allow meeting attendees to see it during off-hours excursions. The weather saved northern resident WFO members from suffering heat-stroke and there was even enough rain to bring a touch of nostalgia. BUSINESS MEETINGS SUMMARY Items discussed at the Board of Directors’ meetings included the status of Western Birds in respect to publication and circulation. Also covered were aspects of business operations of WFO, communications and relationships with members and authors, and ways of improving these. Board members were assigned to new committees dealing with the journal, membership pro- motion, and with finances and budget. The membership elected Laurie Binford, John Luther and Virginia Johnson to three-year terms on WFO’s Board of Directors. The Board elected Terry Wahl as President, Laurie Binford as Vice-president, Garth Alton as Membership Secretary/Treasurer, and Jean-Marie Spoelman as Recording Secretary for one year terms. Peter Gent was appointed chairman of the nominating committee for next year’s meeting. Members should contact him with any ideas on board or officer nominations. Bruce Webb was appointed Photo Editor and WFO annual meeting coordinator to work with local committees. The location and dates of the annual meeting for 1984 were not set but members will be advised as soon as possible on this. WESTERN BIRDS Editor Alan Craig, Associate Editors Narca Moore-Craig and Cameron Barrows, Layout Artist Virginia Johnson and the circulation crew in San Diego have succeeded in bringing WFO’s journal up to date, fulfilling the outline in the President’s Message [WB 13(1-4) ;42], Issue 4 of Volume 14 is scheduled to be mailed in January 1984, after the Christmas mail rush. As explained in the last President’s Message, the Board of Directors decided in 197 1982 that the only way to bring WB’s publishing schedule to its calendar year was to publish Volume 13 as one issue, and to cover the cost of this from within the dues received for Volume 14. A word of explanation about Volume 13 (1-4): this issue was unfortunately delayed by two months due to a major paper being withdrawn by the author after the final proof for the issue had been returned to the printer. It is kind of thing which, in spite of valiant efforts of both editorial staff and printer in changing layout, articles and art- work, can cause much frustration and delay. We regret this and we hope members, awaiting their issues at the mailbox, will understand retroactively. We can also report that a back-log of accumulated manuscripts has been pro- cessed and WB is as “current” as possible in receipt, review, and publication of articles and notes submitted. FINANCES As anticipated when the decision to publish five issues within a year was made, it has taken virtually all of our cash reserves to accomplish this. Paying necessary printing and mailing bills will require careful cash management of dues receipts in the near future. The Board is confident that problems will be minimal and, assuming support from members through renewal of existing memberships and gains in new memberships, WFO will be in solid shape financially. MEMBERSHIP RENEWAL NOTICES FOR VOLUME 15 - 1984 Members received notices for renewal of 1983 memberships in September-October 1983. This was late, but we are trying to keep dues notices in sequence with WB mailings. Correspondingly, notices for renewal of memberships for 1984 will be sent out in early January 1984. This is cer- tainly close timing, but members will receive four issues between the two membership renewal notices. We hope this is not confusing and that you will support WFO by renewing promptly. Your support by doing this, and by en- couraging new memberships and submission of articles to the journal will determine WFO’s future ability to put out a quality journal. Thanks. 198 NOTES FIRST VERIFIED CAPE MAY WARBLER FOR OREGON JEFF GILLIGAN, 26 N.E. 32nd Avenue, Portland, Oregon 97232 OWEN SCHMIDT, 1220 N.E. 17th Avenue #2-D, Portland, Oregon 97232 This note reports the first verified record of the Cape May Warbler {Dendroica tigrina) from Oregon. We watched a warbler of this species for a little over 2 hours as it fed in alder (Alnus) trees on the Bayocean Sandspit, Tillamook County, Oregon, on 19 October 1980. More than 20 photographs which clearly show identifying marks were obtained. The warbler was a male in basic plumage. Its identification was based on the follow- ing characteristics, all of which are apparent in at least some of the color transparencies on file with the Oregon Field Ornithologists’ Bird Records Committee (P.O. Box 10373, Eugene, OR 97440). A large, thick whitish wing bar was on the otherwise gray-green wing. A large, dull yellow patch was behind the ear. The breast and sides were yellow, heavily streaked with black, with the streaking extending onto the lower throat. The yellow of the breast faded into the whitish belly and undertail coverts. The undertail was whitish. The top of the head and back were gray-green, flecked with in- conspicuous dark markings. The upper tail was similar in color to the back. The face was yellowish, washed with gray on the cheek. The lores were thin and dark and there was a small amount of dark behind the eyes. The rump was yellow, although not as bright as that of the Yellow-rumped Warbler (D. coronata) . Cape May Warbler, Bayocean Sandspit, Tillamook Co., Oregon, 19 October 1980. Photos by Owen Schmidt Western Birds 14: 199-200, 1983 199 NOTES We heard the warbler give an occasional weak chip call. The bird seemed to be a bit smaller than D. coronata. There are two previous sight records of the Cape May Warbler from Oregon, both from Malheur National Wildlife Refuge in Harney County. The first sighting was of an alternate plumaged male watched for approximately 20 minutes at the Buena Vista Patrol Station on 9 June 1967 (Littlefield 1973). The second was also an alternate plumaged male seen at the refuge headquarters by John Gatchct, Charles Hanson, Keith Perrin, Alan Stoops, Jr., and Alan Stoops, Sr., on 3 June 1978 (Anonymous 1980) . The latter record and the record for Bayocean Sandspit have been accepted by the Oregon Bird Records Committee. LITERATURE CITED Anonymous. 1980. Oregon Bird Records Committee — Historic actions report. Oregon Birds 6:90. Littlefield, C D. 1973. Unusual bird records from southeastern Oregon. Auk 90:680-682. Accepted 24 September 1983 200 Cape May Warbler Sketch by Donna Dittmann NOTES OREGON’S FIRST RECORDS OF THE GREAT-TAILED GRACKLE CARROLL D. LITTLEFIELD, U S. Fish and Wildlife Service, Box 113, Burns, Oregon 97720 The Great-tailed Grackle (Quiscalus mexicanus) was first recorded in Oregon on 16 May 1980, when an adult male was seen by numerous observers at Malheur Field Sta- tion (MFS), ±50 km SSE of Burns, Harney Co., Oregon. The individual was con- sistently observed within 10 m as it fed with Yellow-headed (Xanthocephalus xan- thocephalus) and Brewer’s (Euphagus cijanocephalus) blackbirds and Brown-headed Cowbirds (Molothrus ater). The grackle was considerably larger than the associating icterids, and the long tail formed the characteristic vee or keel. The eye color was yellow. A photograph of the bird was published in American Birds (Rogers 1980a). Following the initial sighting, several other Great-tailed Grackles were found in Oregon during 1980 and 1981. Since the turn of the century several avian species have been expanding their range northward in North America. East of the 100° meridian the Red-bellied Woodpecker (Melanerpes carolinus), Tufted Titmouse (Parus bicolor), Carolina Wren (Thr\;othorus ludovicianus), Northern Mockingbird (Mimus poli^glottos) and Northern Cardinal (Cardinalis cardinalis) have invaded regions where they were absent in 1900. West of the 100° meridian Magnificent Hummingbird (Eugenes fulgens), Western Kingbird (Ti/rannus uerticalis), Curve-billed Thrasher (Toxostoma curuirostre) and others have also expanded their range northward. Most of these range expansions have resulted from man’s drastic and widespread changes of the environment (Terres 1980). In the east, forest clearings and urban developments and, in the west, shelterbelts, vegeta- tion plantings around human settlements, and water and agricultural developments have created habitat that was not available 80 years ago. The Great-tailed Grackle is among the species that has moved north from its original range. At the turn of the century the species occupied brush habitat from southern Texas, New Mexico and Arizona, south through Mexico and Central America, to nor- thern South America (Oberholser and Kincaid 1974). About 1912, grackles began moving north from south Texas. The range expansion was slow at first, but a rapid in- vasion into west Texas occurred in the 1940s and 1950s. By 1958 it had arrived in the Texas Panhandle (Oberholser and Kincaid 1974). I found two Great-tailed Grackle nests in the panhandle’s southwest corner (± 20 km S of Friona, Parmer Co.) in June 1961. Faanes and Norling (1981) described the species’ range expansion through Texas, Oklahoma, Kansas and Colorado, and reported on the first nesting record for Nebraska. In the 1970s, somewhat later than the Great Plains invasion, the Great-tailed Grackle began spreading from southern New Mexico and Arizona. Extensive deserts probably delayed their progress north of much of their original range, particularly in Arizona, until sufficient habitat changes had occurred. On 1 May 1973, the species was seen at Havasu National Wildlife Refuge (NWR), Mohave Co., in northwest Arizona. The first record in Nevada occurred 16 April 1973 near Las Vegas, Clark Co. (Oberholser and Kincaid 1974) . A bird observed at Ruby Lake NWR, Elko Co. . on 15 May 1978 was the first report from northern Nevada (Kingery 1978). In the summer of 1979, Utah had its first record when a single bird was seen near St. George, Washington Co.; and on 13 and 18 May 1980, two to eight individuals were recorded in the same county (Kingery 1980). A westward expansion was also occurring. Small (1974) reported it was first noted in the lower Colorado River Valley, California, in 1964, and was nesting by 1969. Western Birds 14; 201-202, 1983 201 NOTES Since the Great-tailed Grackle was first seen in Oregon in mid-May 1980, several additional records have accumulated. Apparently, several males were present in 1980. 1 know of the following records: one at Page Springs Campground, 4 km SE of Frenchglen, Harney Co., on 17 May; two at John Day Fossil Beds National Monu- ment, Grant Co., on 18 May; and one had reached northeast Oregon near La Grande, Union Co., on 5 June (Rogers 1980b). I also know of four records in 1981: one male at MFS on 8 and 9 April; one photographed at Fields, Harney Co., during mid-May (H. Nehls pers. comm.) ; one male at Page Springs Campground on 19 June (D. Taylor pers. comm.); and another male in Hines, Harney Co., on 19 July (S. Thompson pers. comm.). Great-tailed Grackles inhabit flatlands and avoid hills, mountains, heavily wooded areas and waterless deserts (Oberholser and Kincaid 1974). Few of these obstacles separate southeast Oregon from the species’ original range in southern Arizona. Great Basin mountain ranges trend mostly north to south. Hills are low and scattered, and heavily wooded areas are non-existent except on isolated mountain ranges. Their ma- jor extrinsic barrier was probably great expanses of waterless desert. The recent in- troduction of mechanized sprinkler irrigation systems has resulted in increased agricultural developments in Nevada and southeast Oregon. These developments have reduced water deficiencies in former expanses of dry desert and may account for the grackle’s rapid invasion into eastern Oregon, compared to the decades it took the species to reach northwest Arizona and southern Nevada from its historical range. ACKNOWLEDGMENTS Larry Ditto, Brad Ehlers, David Paullin and Steven Thompson reviewed an early draft of this manuscript. I would like to thank them for their time and helpful com- ments. Harry Nehls refereed the manuscript and made many valuable suggestions. Dee Dee Ehlers typed the report. LITERATURE CITED Faanes, C.A. & W. Norling. 1981. Nesting of the Great-tailed Grackle in Nebraska. Am. Birds 35:148-149. Kingery, H.E. 1978. The spring migration. Mountain west region. Am. Birds 32:1036-1040. Kingery, H.E. 1980. The spring migration. Mountain west region. Am. Birds 34:800-803. Oberholser, H.C. & E.B. Kincaid, Jr. 1974. The bird life of Texas, Vol. 2. Univ. Texas Press, Austin and London. Rogers, T.H. 1980a. The spring migration. Northern Rocky Mountain - intermountain region. Am. Birds 34:797-800. Rogers, T.H. 1980b. The nesting season. Northern Rocky Mountain - intermountain region. Am. Birds 34:911-914. Small, A. 1974. The birds of California. Winchester Press, New York. Terres, J.K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York. Accepted 26 September 1983 202 NOTES A BRISTLE-THIGHED CURLEW AT LEADBETTER POINT, WASHINGTON RALPH S. WIDRIG, Box 43, Ocean Park. Washington 98640 On 1 May 1982 I found a Whimbrel-like shorebird feeding alone at the high tide mark on an exposed sandy beach at Leadbetter Point, Pacific Co., Washington (Figure 1). The bird closely resembled a Whimbrel (Numenius phaeopus), but seemed to be more warm brown in color and to have a more erect posture. When flushed at about 30 m the bird gave a slurred call somewhat like that of a Black-bellied Plover (Pluvialis squataroia), but lower in pitch. The call was given only once as the bird flushed. As it circled low over the water in bright sunlight its rump and tail appeared to be a light tawny or buff color. After it resettled on the beach I approached the Whimbrel- sized bird from the sand dunes and observed it from a distance of about 25 m. Its bill was like that of a Whimbrel but somewhat more decurved; its legs were blue-gray, and its posture rather erect. When 1 rose, it flushed giving the same short, three-note call heard before, which seemed to say “chi-u-it” as described by Peterson (1961). Again, the rump and tail were a striking buff or light tawny color in flight, the rump being the lighter. This pattern was clearly visible for some distance as the bird flew down the beach. The observations were made with 7x 35 Nikon binoculars. The bird was un- questionably a Bristle-thighed Curlew (Numenius tahitiensis) . It was almost identical to Figure 1. Leadbetter Point. Washington. The x marks location of Bristle-thighed Curlew observation on 1 May 1982. Leadbetter Point is the northern terminus of Long Beach Peninsula, which separates Willapa Bay from Pacific Ocean near mouth of Columbia River. The habitat is protected, being part of Willapa National Wildlife Refuge. Western Birds 14: 203,204, 1983 203 NOTES Peterson’s field guide illustration (1961: Plate 26), except that the tail pattern could only be seen in flight. This rare species breeds locally in western Alaska (Allen 1948, Gibson 1979). Its normal migration route is directly south over the Pacific Ocean by way of the Hawaiian and other central Pacific islands, although at least six records have been reported for the Gulf of Alaska from Kodiak to Yakutat (Bent 1929, Gibson 1978, Isleib and Kessel 1973). A single bird was collected at Grant Bay, near the north end of Vancouver Island, on 31 May 1969 (Richardson 1970). The first reported occurrence of tahitien- sis in the contiguous 48 United States was of two observed at close range in low, northward flight at Leadbetter Point on 18 May 1980 (Ulrich Wilson pers. comm.). A light rump and brick-red tail pattern was clearly noted on both birds as they flew by together. No call was given. Most of the above sightings were on sandy ocean beaches during May, and the birds were not associating with Whimbrels or other shorebird species. ACKNOWLEDGEMENTS The manuscript was reviewed by Dennis Paulson and Terry Wahl, who made helpful comments. LITERATURE CITED Allen, A. A. 1948. The curlew’s secret, Natl, Geographic Mag. 94:751-770. Bent, A.C. 1929. Life histories of North American shore birds. U.S. Natl. Mus. Bull. 146. Gibson, D.D. 1978. The fall migration. Alaska region. Am. Birds 32:244. Gibson, D.D. 1979. The nesting season. Alaska region. Am. Birds 33:889. Isleib, M.E. & B. Kessel. 1973. Birds of the North Gulf Coast-Prince William Sound region, Alaska. Biol. Papers Univ. Alaska. No. 14. Peterson, R.T. 1961. A field guide to western birds. Houghton Mifflin, Boston. Richardson, F. 1970. A North American record of the Bristle-thighed Curlew outside Alaska. Auk 87:815. Accepted 15 October 1983 204 NOTES CAVITY-NESTING BREWER’S BLACKBIRDS LYMAN V. RITTER and KATHRYN PURCELL, PSW Forest and Range Experiment Station, Forestry Sciences Laboratory, 2081 E. Sierra Avenue, Fresno, California 93710 Nest sites of the Brewer’s Blackbird (Euphagus ct^anocephalus) are unusually diverse — on the ground in weedy cover, in stump crevices, shrubs or trees (Verner and Boss, California wildlife and their habitats: Western Sierra Nevada, USDA Forest Service Gen. Tech. Report PSW-37, Berkeley, CA, 1980). In Washington, Dawson and Bowles (The Birds of Washington, Occidental Publishing Co., Washington, 1909:47) described nesting “in cavities near the tops of some giant fir stubs, none of them less than 150 feet from the ground.” We have found no other reference to cavity nesting by Brewer’s Blackbirds. This note reports on a nest cavity used by Brewer’s Blackbirds for three consecutive years in Poison Meadow, Sierra National Forest, Fresno County, California (TIOS, R25E, Sec. 5) , at an elevation of 1755 m. The meadow covers about 5 ha, has a per- manent stream, is bisected by a paved road, and is surrounded by mixed-conifer forest. Scattered clumps of willow {Salix sp.) grow along the stream. The nest cavity was in a 13-m Ponderosa Pine (Pinus ponderosa) snag measuring 65 cm dbh, with several large branches remaining, and about 15% bark covering. It was located 15 m from the nearest edge, 10 m from the road, and 10 m from standing water. The cavity was in an enlarged, abandoned woodpecker hole 2.4 m above the ground. It faced 282° WNW. The opening was approximately rectangular, measuring about 6 X 10 cm. The rim of the nest was nearly up to the bottom of the cavity open- ing, so the adults could feed the nestlings without entering the cavity, and incubating and brooding adults could sometimes be seen in the opening. The nest was first discovered with five nestlings on 12 June 1980. All nestlings were present on 17 June, but three fledged during an attempt to photograph them. By 22 June the nest was empty. On 10 June 1981 it contained three nestlings, and a fourth was found dead below the cavity. They were judged to be about 8 days old. Again on 7 June 1982 adult Brewer’s Blackbirds were seen entering the cavity, and an undeter- mined number of nestlings were being fed there on 14 June. Presumably the young fledged between 15 and 20 June, as the cavity was empty on 21 June. During the three seasons we knew that Brewer’s Blackbirds nested in the cavity, a pair of White-headed Woodpeckers (Picoides albolawatus) also nested in the snag. Their cavity was 2.0 m above ground— only 36 cm from the cavity used by the blackbirds— and faced 356° N. We observed no interactions between these species. Accepted 11 October 1983 Western Birds 14: 205, 1983 205 NOTES HOUSE WREN BREEDS IN CLIFF SWALLOW NEST BRUCE ELLIOTT, California Department of Fish and Game, 2201 Garden Road, Monterey, California 93940 On 25 June 1983 1 observed a Northern House Wren (Troglodytes aedon) feeding an undetermined number of nestlings in a nest of a Cliff Swallow (Hirundo pyr- rhonota) . The nest was located under the Bradley Road Bridge spanning the Salinas River in southern Monterey County, California, and was approximately 20-25 m above the river bank. Two additional swallow nests, one active, were immediately ad- jacent to the one used by the wren. Approximately 300 other active swallow nests were on the outer border of the bridge, separated from direct view of the wren nest by a lateral support beam. I observed the wren for about 45 minutes foraging repeatedly in exotic weedy vegetation in the shade under the bridge. It would periodically return to the nest with food. Northern House Wrens are cavity nesters. The vast majority of their nest sites are natural crevices in trees or posts, cavities developed by other bird species for their own nesting requirements, or man-made birdhouses. However, House Wrens are known to utilize every kind of suitable aperture from hollow gourds to pockets of clothing hanging in buildings (Bent, A.C., U.S. Natl. Mus, Bull. 195, 1948). Although Bent does refer to one occurrence of a House Wren nesting in a Bank Swallow (Riparia riparia) burrow, I have been unable to locate any reference to use of Cliff Swallow mud-gourd nests by any wren species. In addition, the height of the nest above ground level is well above the usual upper height limit of 3 m for House Wren nests. Bent (ibid.) lists one nest in a dead yellow pine stub 50 m above ground, but also states that “ . . . heights of 20 to 30 feet are unusual.” Thus, the Bradley Bridge nest is unusual for its structure and its elevation and emphasizes the plasticity of the House Wren’s behavior in selecting a nest site. Accepted 11 October 1983 206 House Wren Sketch by Joseph C. Rigli Western Birds 14: 206, 1983 NOTES A WHITE IBIS NEAR SHERIDAN, WYOMING HELEN DOWNING, 371 Crescent Drive, Sheridan, Wyoming 82801 A 7-year-old ranch boy, Charles Collins, found “a funny white bird” in a small marshy pond near his home on Lower Piney Creek about 40 km SSE of Sheridan, Wyoming, on 12 September 1976. His father, Bruce Collins, identified it as a White Ibis (Eudocimus albus). Marian Collins (not a relative) and I arrived at the pond at about 0730 on 13 September. The pond, situated in a pasture, was not more than 8 m across and had cattail (Tijpha) growth and two tree stumps standing in water near its center. The rest of the pasture was rather level and dry with short grass clipped off by the cattle present. The entire valley is made up of such pastures, some plowed and planted fields, some native grasses and sagebrush (Artemisia), cottonwoods (Populus) and willows (Salix) along the stream plus large brushy areas. Low hills rise on either side. Several marshy ponds are in the area — two quite extensive. Piney Creek flows generally from southwest to northeast through the valley. As we drove up 1 saw the bird in the shallow water among some vegetation and near a tree stump. I saw the back of the head (neck drawn back) and the bird’s back — it was white with some dirt on the plumage. The bird turned its head and revealed the long, pinkish-red, down-curved heavy bill clearly — truly an adult White Ibis. We parked the car within 40 m of the bird and observed it, using 7x35 binoculars. The bird was preening in full sun. Its bill was about as long as its neck, about 30 cm. It had much bare, bright red skin visible on the face, up as much as 5 cm over the eye and covering the face area. This red skin was as wide as 5 cm in a sort of square area below the eye. The ibis hopped up onto the stump spreading its wings and exposing its black wing tips and long, pinkish-red legs. 1 used a 40x scope to better view its face and noted that the bird had a black pupil and a yellow iris. We watched the ibis for about an hour, and again later that morning we watched it with Platt H. Hall as it fed in the pasture among the cattle. I guessed it was picking up grasshoppers, which were abundant. The ibis walked rather deliberately but not as slowly as a Great Blue Heron. It moved its head, chicken-like, back and forth as it walked. The ranchers said that the stump in the center of the pond appeared to be a favorite perch, as the ibis returned to it again and again. The White Ibis was still present at the original site until about noon on 13 September 1976, according to the ranchers. On 14 September 1976 Oliver K. Scott and I thoroughly searched all the sloughs, marshy areas and ponds in the area but were unable to find the bird. The sighting represents a first state record as far as I can determine. N.W, Whitney cited a record in Bent (1926): two White Ibis were seen and one was collected in southeastern South Dakota in May 1879. Bent also noted a few near Ogden, Utah, 1 September to 8 October 1871; a specimen taken at Barr Lake, Colorado, in 1890; and others as far north as Illinois, Vermont, Connecticut and New York in 1878, 1878, 1875 and 1836-43, respectively. Recent bird checklists for Wyoming, Montana and Colorado do not include the White Ibis. Scott suggested that the bird might be an escapee. Two small aviaries near Sheridan have never had a White Ibis. Ann Schimpf checked the Salt Lake City area with negative results; Esther Serr had the same results in the Rapid City, South Dakota, area; P.D. Skaar knew of no such captive bird in the Bozeman or Billings. Montana, areas; and Hugh Kingery wrote that the bird was not an escapee from the Denver, Colorado, area. No information was received through the National Zoo Keepers’ publication. One might wonder if the bird was an albino White-faced Ibis (Plegadis chihi), a rare spring migrant in the Sheridan area. This possibility is ruled out by the bird’s black Western Birds 14; 207-208, 1983 207 NOTES pupil and yellow iris, very red facial skin, bright pinkish-red bill and legs, and black wing tips. Some investigation has been made about how the White Ibis might have appeared here. The National Weather Service office personnel in Sheridan reported that, off the coast of Baja California during late August and early September, two or three tropical depressions had strong winds aloft at about 10,000 to 12,000 feet — fully strong enough to bring such a bird to this area. They also said that Hurricane Kathleen, which had moved up through Baja California into the Southwest at the time, was not respon- sible for the air mass over Sheridan from 10-13 September 1976, although the hur- ricane “ . . . produced record rains as far north as Idaho” (Kaufman 1977:145). The probability of the White Ibis wandering to Wyoming from the Gulf of Mexico or Florida seems unlikely as a high pressure area with mild wind velocities was situated just east of the Rocky Mountains. Of the ornithologists and qualified birders who expressed an opinion concerning the origin of the White Ibis in northeastern Wyoming, three suggested it was a post- breeding wanderer but declined to guess from where, and four thought that it was brought here via the southwestern United States by the strong weather pattern aloft. I favor the latter explanation . LITERATURE CITED American Ornithologists’ Union. 1957. Check-list of North American birds. 5th ed. Am. Ornithol. Union, Baltimore, MD. Bent, A.C. 1926. Life histories of North American marsh birds. U.S. Natl. Mus. Bull. 135. Kaufman, K. 1977. The changing seasons. Am. Birds 31:142-152. Palmer, R.S., ed. 1962. Handbook of North American birds, Vol. 1. Yale Univ. Press, New Haven and London. Accepted 21 September 1983 White Ibis Sketch by Tim Manolis 208 NOTES UNUSUAL BEHAVIOR OF THE HORNED LARK TIMOTHY D. REYNOLDS, Biology Department, Idaho State University, Pocatello, Idaho 83209 (present address: Department of Energy, Idaho Operations Office, RESL/CF-690, 550 Second Street, Idaho Falls, Idaho 83401) DOUGLAS P. SHOREY, Biology Department, Idaho State University, Pocatello, Idaho 83209 (present address: Spray High School, Spray, Oregon 97874) At 0720 (MST) on 12 May 1976, while conducting bird census work on the Idaho National Engineering Laboratory (INEL) 2 km west of Atomic City, Bingham Co., Idaho, we noticed a Horned Lark (Eremophila alpestris) dead on the road and a con- specific acting strangely nearby. Observing the birds from our vehicle, we recorded the following information from a distance of 5 m. The live bird was paler and less distinctly marked than the dead one. We therefore classified the former as a female, the latter a male. A necropsy later confirmed the male’s sex. The birds were on an infrequently traveled road in a habitat dominated by Big Sagebrush (Artemisia tridentata) . They were within 150 m of two Horned Lark nests with eggs we had located on 10 and 11 May. Although direct evidence was lack- ing, the subsequent behavioral displays by the live bird indicated that the birds we were observing had most likely been a mated pair. We first saw the female within 1 m of the carcass. She was obviously greatly agitated, hopping and flying very short distances in a sporadic manner. She flapped violently in an exaggerated fashion, hovering for a second or less and landing within 0.5 m of the point of takeoff. She spent an instant motionless on the ground, and then fluttered and hopped toward the carcass, twice actually landing on it. Using her beak she grabbed the dead bird three times by the wing and several times by the head, pulling it towards the side of the road roughly in the direction of the nests. She then flew to a sagebrush about 2.5 m distant, called in a high fast chipping manner for about 5 seconds, and returned to the road with sporadic and exaggerated wing-fluttering. She then resumed hopping about, fluttering, prob- ing, tugging at the body, and chipping intermittantly. We observed this behavior sequence six times in 10 minutes and then approached the birds. By this time, the carcass had been moved about 0.5 m from the original position . As we advanced the female did not flush from her position by the carcass un- til we were within 1.5 m. She then flew only about 3 m away, landed in a sagebrush and resumed the high-pitched chipping mentioned previously. When we left the car- cass, she immediately returned to her former position and continued her agitated behavior. We observed for several minutes more, and left the area. When we returned 6 hours later, only the carcass remained. It had been moved completely off the road, approximately 1 m from where we had last seen it. Later investigations revealed that both of the Horned Lark nests in the vicinity of the displays were unsuccessful. One was found empty (predation?) 2 days after our observations, and hatchlings in the sec- ond nest were trampled by domestic sheep nearly a week later. The behavior of the live bird strongly suggests that these Horned Larks were a mated pair. A similar increase in activity and call rate upon separation from a mate has been recorded for Zebra Finches (Poephila guttata), Eurasian Bullfinches (P^rrhula Pi/rrhula), Eurasian Tree Sparrows (Passer montanus) and Bearded Tits (Panurus biarmicus) (Butterfield 1970, Wickler 1972:95-99). All these passerine species reportedly pair for life. To our knowledge, ours is the first description of behavior Western Birds 14: 209-210, 1983 209 NOTES which suggests postmortem mate fidelity in a passerine species that, at the most, forms a pair bond for only one breeding season. This contribution is from the INEL Radioecology and Ecological Studies Programs, supported by the Division of Biomedical and Environmental Research, U.S. Depart- ment of Energy. Charles H. Trost, Jeanne Conry and Bruce Webb reviewed drafts of the manuscript. Their cogent suggestions were appreciated. LITERATURE CITED Butterfield, P.A. 1970. The pair bond in the Zebra Finch. Pp 260-264 in J.H. Crook, ed. Social behavior in birds and mammals; essays on the social ethology of animals and man. Academic Press, New York. Wickler, W. 1972. The sexual code; the social behavior of animals and man. Double- day, Garden City, NY. Accepted 31 October 1983 Horned Lark Sketch fay Keith Hansen 210 INDEX, WESTERN BIRDS, VOLUME 14, 1983 Compiled by Mildred Cornar Aethia cristatella, 1, 7, 47-48 pusilla, 127, 131 Aimophila cassinii, 12, 134 Alauda arvensis, 113-126 a. blackistoni, 123 a. dulciuox, 121, 123 a. intermedia, 123 a. kiborti, 123 a. lonnbergi, 123 a. pekinensis, 121, 123 gulgula, 115, 118-120, 122 g. inopinata, 122 g. japonica, 122 razae, 117 Albatross, Black-browed, 135 Amakihi, Common, 74, 77, 82 Ammodramus leconteii, 134 Ammospiza caudacuta, 12, 15 Anas querquedula, 4 Anhinga, 143 Anhinga anhinga, 143 Ani, Groove-billed, 7 Anthus ceruinus, 9, 13, 121, 133 spinoletta, 114 spragueii, 9, 133 Apapane, 82 Aphelocoma coerulescens, 147-148 Archilochus alexandri, 24-28 Ardea herodias, 169-184 Atwood, Jonathan L. and Dennis E. Minsky, Least Tern foraging ecology at three major California breeding colonies, 57-72 Auklet, Cassin’s47 Crested, 1,7, 47-48 Least 127, 131 Rhinoceros, 47 Aylhya fuligula, 4 Baldridge, Frank A. , Lloyd F. Kiff, Susan K. Baldridge and Robert B. Fiansen, Hybridization of a Blue-throated Hummingbird in California, 17-30 Baldridge, S. K. , see Baldridge, F. Bartramia longicauda, 4. 130 Binford, Laurence C,. Sixth Report of the California Bird Records Committee, 127-145; see Howell, J. Blackbird, Brewer’s, 205 Bloom, Peter H,, Notes on the distribution and biology of the Flammulated Owl in California, 49-52 Boarman , W, I . , see Howell, J . Booby, Brown, 3 Red-footed, 136 Boyce, Walter and Lee Elliot, First record of a Snow Bunting in Arizona, 54 Bubo virginianus, 155 Bunting, Painted, 134 Snow, 12, 15, 54, 134 Buteo albonotatus, 13, 129, 137 Butler J., see Pitman, R. Calandrella rufescens, 117 Calcarius lapponicus, 114 ornatus, 114 pictus, 116 Calidris acuminata, 5, 14, 130-131 ferruginea, 131 fuscicollis, 6. 7 minuta. 138 pusilla, 6, 14, 130, 137. 138, 139 ruficollis, 138, 139 Cal[;pte anna, 24-28 costae, 24-28 Cardellina rubrifrons, 11, 31-38, 134 Casmerodius albus, 169-184 Catbird, Gray, 13, 132 Cathartes aura, 136 Catharus fuscescens, 13, 141 minimus, 9 Cepphus columba, 43 Cerorhinca monocerata, 47 Chachalaca, Plain, 13 Chappell, Christopher B. and Brenda J. Ringer, Status of the Hermit Warbler in Washington, 185-196 Charadrius mongolus, 1,4, 5 wilsonia, 4 Chen canagica, 4 Chickadee, Mountain, 35, 36 Cistothorus platensis, 1, 8 Columba liuia, 43, 44 Contopus pertinax, 8, 132 Virens, 13 Coragijps atratus, 136 Corvus brachi^rh^incbos, 155 Western Birds 14: 211-215, 1983 211 Cotton, J., see Pitman, R. Coturnicops noveboracensis, 13, 137 Creeper, Hawaii, 73-84 Crossbill, White- winged, 1, 12 Crotophaga suldrostris, 7 Crow, Common, 155 Curlew, Bristle-thighed, 203-204 Cyanocitta cristata, 8 Cygnus buccinator, 4, 13, 129, 136 Ci,)nanthus latirostris, 8, 132, 140 Daption capense, 12 DeGange, A. R. , see Howell, J. Dendroica cerulea, 10, 15 coronata, 36 dominica, 10, 133 graciae, 11, 133 nigrescens, 185 occidentalis, 185-196 pinus, 11, 15, 142 striata, 142 tigrina, 199-200 townsendi, 185, 193, 194 Diomedea melanophris, 135 Dove, Rock, 43, 44 Downing, Helen, White Ibis near Sheridan, Wyoming, A., 207-208 Duck, Tufted, 4 Dumetella carolinensis, 13, 132 Dunn, J., see Luther, J. Egret, Great, 169-184 Reddish, 3, 129 Snowy, 169-184 Egretta caerulea, 1 79 rufescens, 3, 129 tbula, 169-184 Eider, King, 129 Elliot, L. , see Boyce, W. Elliott, Bruce G., House Wren breeds in Cliff Swallow nest, 206; Nocturnal moonlight calling by Elegant Trogon in Arizona, 53 Empidonaxfiauiuentris, 1,8 hammondii, 140, 141 minimus, 8, 13, 132, 140-141 Eremophila alpestris, 114, 115, 120, 209-210 Erickson, R. A., see Morlan, J. Eudocimus albus, 3, 143, 207-208 Eugenes fulgens, 15 Euphagus cyanocephalus, 205 Findholt, Scott L. and Sam D. Fitton , Records of the Scott’s Oriole from Wyoming, 109-110 Fitton, S. D. , see Findholt, S. Flycatcher, Dusky-capped, 132 Great Crested, 13, 132 Hammond’s 140, 141 Least, 8, 13, 132, 140-141 Sulphur-bellied, 8, 132 Yellow-bellied, 1, 8 Franzreb, B. J., see Franzreb, K. Franzreb, Kathleen E. and Barbara J. Franzreb, Foraging ecology of the Red-faced Warbler during the breeding season, 31-38 Fregetta grallaria, 12 Friedrichsen, G., see Pitman, R. Galerida cristata, 116 deva, 116 fremantilii, 116 magnirostris, 116 malabarica, 116 modesta, 116 Garganey, 4 Gavia adamsii, 2, 12, 56, 129, 146 arctica, 56 immer, 56 stellata, 55-56 Gilligan, Jeff and Owen Schmidt, First verified Cape May Warbler for Oregon, 199-200 Godwit, Hudsonian, 130 Golden-Plover, Greater, 13 Goose, Emperor, 4 Grackle, Common, 11, 15, 134 Great-tailed, 201-202 Grebe, Least, 12 Grosbeak, Black-headed, 159-167 Guillemot, Pigeon, 43 Gull, California, 106 Common Black-headed, 6, 131 Glaucous-winged, 87, 88, 89, 106 Heermann’s, 39-46 Herring, 88, 89, 98, 106 Little, 6, 131 Ring-billed, 103 Thayer’s, 106 Western, 40, 43, 44, 85-107 Yellow-footed, 85-107 Haematopus bachmani, 43, 44 palliatus, 4, 130 Hansen, R. B., see Baldridge, F. Harris, Roger D., Albinistic Red-breasted Sapsucker, 168 Hawk, Harris, 13, 15 Zone-tailed, 13, 129, 137 Helmitheros vermivorus, 10 Hemignathus uirens, 74, 77 , 82 212 Heron, Great Blue, 169-184 Little Blue, 179 Night, see Night-Heron Heteroscelus brevipes, 127, 130 Himatione sanguinea, 82 Hirundo p\^rrhonota, 206 Howell, Judd, David Laclergue, Sharon Paris, William I. Boarman, Anthony R. DeGange and Laurence C. Binford, First nests of Heermann’s Gull in the United States, 39-46 Hummingbird, Allen’s, 26 Anna’s, 24-28 Black-chinned, 24-28 Blue-throated, 17-30 Broad-billed, 8, 132, 140 Calliope, 26 Costa’s 24-28 Rivoli’s, 15 Rufous, 26 H\;locichla mustelina, 8-9 Ibis, White, 3, 143, 207-208 White-faced, 207 Icterus parisorum, 109-110 liwi, 82 Inkley, Douglas B., Transparent nest box for swallows, A, 112 Jay, Blue, 8 Scrub, 147-158 Johanos, T. C., see Sakai, H. Kiff, Lloyd F., see Baldridge, F. Kingbird, Thick-billed, 132 Kinglet, Ruby-crowned, 35, 36 Kittiwake, Red-legged, 139 Laclergue, D., see Howell, J. Lampornis clemenciae, 17-30 Lark, African sun, 116 Crested, 116 Horned, 114, 115, 120, 209-210 Lesser Short-toed, 117 Razo Island, 117 Wood. 116-117 Larus argentatus, 88, 89, 98, 106 californicus, 106 delawarensis, 103 glaucescens, 87, 88. 89, 106 heermanni, 39-46 livens. 85-107 minutus, 6, 131 occidentalis, 40, 43. 44. 85-107 ridibundus, 6. 131 thayeri. 106 Limosa haemastica, 130 Littlefield, Carroll D., Oregon’s first records of the Great-tailed Grackle, 201-202 Longspur, Chestnut-collared, 114 Lapland, 114 Smith’s, 116 Loon, Arctic, 56 Common, 56 Red-throated, 55-56 Yellow-billed, 2, 12, 56, 129, 146 Loxia leucoptera, 1, 12 Lullula arborea, 116-117 Luther, John S., Guy McCaskie and Jon Dunn, Fifth report of the California Bird Records Committee, 1-16 Lymnocri^ptes minimus, 13 McCaskie, Guy, Another look at the Western and Yellow-footed gulls. 85-107; see Luther, J. Minsky, D. E., see Atwood, J. Morlan, Joseph, Identification quiz [Red-throated Loon,] 55-56; and Richard A. Erickson, Eurasian Skylark at Point Reyes, California, with notes on skylark identification and systematics, A, 113-126 Motacilla alba, 9, 127 cinerea, 142 flava, 13, 127 lugens, 9, 121, 127 Murre, Common, 139 Thick-billed, 139-140, 145 Murrelet, Craveri’s, 47 Myiarchus crinitus, 13, 132 tuberculifer, 132 Mijioborus pictus, 127 Mi;iod[^nastes luteiuentris, 8, 132 Newcomer, M., see Pitman, R. Night-Heron, Black-crowned, 169-184 Yellow-crowned, 3. 12, 129 Numenius tahitiensis, 203-204 Nyctanassa, see N\jcticorax Ngctea scandiaca, 7, 14 N\jcticorax nycticorax, 169-184 uiolacea, 3, 12. 129 Oceanites oceanicus, 3, 12 Oceanodroma castro. 1, 3 tethys, 3, 135-136 Oenanthe oenathe, 13, 121 Oporornis agilis, 11. 15. 134, 142 formosus, 142 Philadelphia, 142 213 Oreomystis mana, 73-84 Oriole, Scott’s, 109-110 Ortalis uetula, 13 Otus flawmeolus, 49-52 Owl, Flammulated, 49-52 Great Horned, 155 Snowy, 7, 14 Spotted, 53 Oystercatcher, American, 4, 130 American Black, 43, 44 Parabuteo unicinctus, 13, 15 Paris, S., see Howell, J. Parus gambeli, 35, 36 Passerculus sandwichensis, 114 Passerina ciris, 134 Petrel, Cape, 12 Cook’s, 1, 2, 129, 135 Stejneger’s, 1, 2 Pewee, Greater, 8, 132 Phaethon rubricauda, 1, 3 Phalarope, Wilson’s, 111 Phalaropus tricolor, 111 Pheucticus melanocephalus, 159-167 Philornachus pugnax, 6, 14, 131 Phoebe, Eastern, 8, 13 Ph\;lloscopus fuscatus, 1, 9, 14 Picoides albolarvatus, 205 Piest, Linden A., First nesting records of Wilson’s Phalarope in Arizona, 111 Pipit, Red-throated, 9, 13, 121, 133 Sprague’s, 9, 133 Water, 114 Piranga olivacea, 11, 134 Pitman, Robert, Michael Newcomer, John Butler, James Cotton and Gary Friedrichsen, Crested Auklet from Baja California, A, 47-48 Plectrophenax nivalis, 12, 15, 54, 134 Plegadis chihi, 207 Plover, Golden, see Golden-Plover Mongolian, 1, 4, 5 Wilson’s, 4 Pluvialis apricaria, 13 Pratt, Helen M., Marin County California heron colonies: 1967-1981, 169-184 Protonotaria citrea, 10, 134 Pterodroma cookii, 1, 2, 129, 135 longirostris, 1, 2 Pfychoramphus aleuticus, 47 Puffin us gravis, 1, 2 tenuirostris, 2, 129 Purcell, K., see Ritter, L. Quiscalus mexicanus, 201-202 quiscula, 11, 15, 134 Rail, Yellow, 13, 137 Redstart, Painted, 127 Regulus calendula, 35, 36 Reynolds, Timothy D. and Douglas P. Shory, Unusual behavior of the Horned Lark, 209-210 Ringer, B. J., see Chappell, C. Rissa brevirostris, 139 Ritchison, Gary, Breeding biology of the Black-headed Grosbeak in northern Utah, 159-167 Ritter, Lyman V., Nesting ecology of Scrub Jays in Chico, California, 147-158; and Kathryn Purcell, Cavity-nesting Brewer’s Blackbirds, 205 Ruff, 6, 14, 131 Sakai, Howard F. and Thea C. Johanos, Nest, egg, young and aspects of the life history of the endangered Hawaii Creeper, The, 73-84 Sandpiper, Buff-breasted, 6, 131 Curlew, 131 Semipalmated, 6, 14, 130, 137, 138, 139 Sharp-tailed, 5, 14, 130-131 Upland, 4, 130 White-rumped, 6, 7 Sapsucker, Red-breasted, 168 Sayornis phoebe, 8, 13 Schmidt, O., see Gilligan, J. Selasphorus rufus, 26 sasin, 26 Shearwater, Greater, 1, 2 Short-tailed, 2, 129 Shorey, D. P, see Reynolds, T Skylark, Eurasian, 113-126 Oriental, 115, 118-120, 122 Snipe, Jack, 13 Somateria spectabilis, 129 Sparrow, Cassin’s, 12, 134 Le Conte’s, 134 Savannah, 114 Sharp-tailed, 12, 15 Sphyrapicus ruber, 168 Stellula calliope, 26 Sterna antillarum, 57-72 sandvicensis, 1, 6-7 Stint, Little, 138 Rufous-necked, 138, 139 Storm-Petrel, Band-rumped, 1, 3 Galapagos, see Wedge-rumped Harcourt’s, see Band-rumped 214 Wedge-rumped, 3, 135-136 White-bellied, 12 Wilson’s, 3, 12 Strix occidentalis, 53 Sula leucogaster, 3 sula, 136 Swallow, Cliff, 206 Tree, 112 Violet-green, 112 Swan, Trumpeter, 4, 13, 129, 136 Si^nthliboramphus craveri, 47 Tachybaptus dominicus, 12 Tachj^cineta bicolor, 112 thalassina, 112 Tanager, Scarlet, 11, 134 Tattler, Gray-tailed, 127, 130 Tern, Least, 57-72 Sandwich, 1, 6-7 Thrasher, Curve-billed, 132 Thrush, Gray-cheeked, 9 Wood, 8-9 Toxostorr}a curuirostre, 132 Troglodi^tes aedon, 206 Trogon, Elegant, 53 Trogon elegans, 53 Tropicbird, Red-tailed, 1, 3 Tr^mgites subruficollis, 6, 131 Tj^rannus crassirostris, 132 Uria aaJge, 139 lomuia, 139-140, 145 Veery, 13, 141 Vermivora cbrj^soptera, 10, 133 Vestiaria coccinea, 82 Vireo, Philadelphia, 10, 13, 133 Red-eyed, 10, 133 White-eyed, 9 Yellow-green, 10, 133 Yellow-throated, 10, 133 Vireo flavifrons, 10, 133 flavouiridis, 10, 133 griseus, 9 olivaceus, 10, 133 philadelphicus, 10, 13, 133 Vulture, Black, 136 Turkey, 136 Wagtail, Black-backed, 9, 121, 127 Gray, 142 White, 9, 127 Yellow, 13, 127 Warbler, Blackpoll, 142 Black-throated Gray, 185 Canada, 11 Cape May, 199-200 Cerulean, 10, 15 Connecticut, 11, 15, 134, 142 Dusky, 1,9, 14 Golden-winged, 10, 133 Grace’s, 11, 133 Hermit, 185-196 Hooded, 11, 134 Kentucky, 142 Mourning, 142 Pine, 11, 15, 142 Prothonotary, 10, 134 Red-faced, 11, 31-38, 134 Townsend’s, 185, 193, 194 Worm-eating, 10 Yellow-rumped, 36 Yellow-throated, 10, 133 Wheatear, Northern, 13, 121 Widrig, Ralph S., Bristle-thighed Curlew at Leadbetter Point, Washington 203-204 Wilsonia canadensis, 11 citrina, 11, 134 Wood-Pewee, Eastern. 13 Woodpecker, White-headed, 205 Wren, House, 206 Sedge, 1, 8 Short-billed Marsh, see Sedge 215 WFO Vagrant Tree Poster A striking black and white poster by Narca Moore-Craig depicts 27 species of known or potential vagrants to Western North America. To order send $10.00 plus $1.00 for postage and handling to Ginger Johnson, 4637 Del Mar Ave., San Diego, CA 92107. Calif, residents please add 6% sales tax. Make checks payable to Western Field Ornithologists. All proceeds go to WFO. 216 Volume 14, Number 4, 1983 Marin County California Heron Colonies: 1967-1981 Helen M. Pratt 169 Status of the Hermit Warbler in Washington Christopher B. Chappell and Brenda J. Ringer 185 Report to Members Terence Wahl, President, Western Field Ornithologists 197 NOTES First Verified Cape May Warbler for Oregon Jeff Gilligan and Owen Schmidt 199 Oregon’s First Records of the Great-tailed Crackle Carroll D. Littlefield 201 A Bristle-thighed Curlew at Leadbetter Point, Washington Ralph S. Widrig 203 Cavity-Nesting Brewer’s Blackbirds Lyman V. Ritter and Kathryn Purcell 205 House Wren Breeds in Cliff Swallow Nest Bruce Elliott 206 A White Ibis Near Sheridan, Wyoming Helen Downing 207 Unusual Behavior of the Horned Lark Timothy D. Reynolds and Douglas P. Shorey 209 INDEX Mildred Comar 211 Cover drawing by Narca Moore-Craig-. Burrowing Owls (Athene cunicularia) Manuscripts should be sent to Alan M. Craig, P.O. Box 254, Lakeview, CA 92353. For matters of style consult Suggestions to Contributors to Western Birds (6 pp. mimeo available at no cost from the Editor) and Council of Biology Editors Style Manual 4th edition, 1978 (available from the American Institute of Biological Sciences, 1401 Wilson Boulevard, Arlington, VA 22209 for $12.00). Papers are desired that are based upon field studies of birds, that are both understand- able and useful to amateurs, and that make a significant contribution to scientific literature. Appropriate topics include distribution, migration, status, behavior, ecology, population dynamics, habitat requirements, the effects of pollution, the techniques for identifying, censusing, sound recording and photographing birds in the field. Papers of general interest will be considered regardless of their geographic origin, but particularly desired are papers dealing with studies accomplished in or bearing on Rocky Mountain states and provinces westward, including Alaska and Hawaii, adjacent portions of the Pacific Ocean and Mexico, and western Texas. Authors are provided 50 free reprints of each paper. Additional reprints can be ordered at author’s expense from the Editor when proof is returned or earlier. hiffC! a 1‘JM!*' qih r jfii F Vii Aur 4F 1 ■ — "j-Tan il'^™ T^*“* 1 %lrf*Str ^ Tj* 'ujLIct luEhiri ■gJ'Qf