HARVARD UNIVERSITY Library of the Museum of Comparative Zoology OCCASIONAL PAPERS MUa COfVif^ iOO of the 4.1BR?ARY MUSEUM OF NATURAL HISTORY , '^ i 0 1934 The University of Kansas HARVARD Lawrence, Kansas UNIVERSITY NUMBER 107, PAGES 1-17 12 DECEMBER 1983 BREEDING BIOLOGY OF HOUSE SPARROWS: INTERCOLONY VARIATION By Peter E. Lowther' The House Sparrow (Passer domesticus) has had a long and close association with human settlement and agriculture (Johnston and Klitz, 1977). In North America, the House Sparrow's association with man began in 1852 with its introduction at New York. Current abundance patterns in North America show greatest numbers of sparrows in the grain producing regions of central North America (Robbins 1973:8). House Sparrows are birds of farmsteads and towns and in these habitats form loose breeding colonies (Summers-Smith, 1954, 1958). My work examined the differences in nesting success observed among several House Sparrow colonies at farmsteads in northeastern Kansas. METHODS AND MATERIALS Study areas.— I studied sparrow colonies on 9 farms located in the southwest corner of Leavenworth County, Kansas (Fig. 1). These farms I identify with landowner's names. Nestboxes were set up at 7 farms during the 1974-1975 winter and at 2 other farms in the fall of 1975 (Murphy, 1977). About 150 nestboxes were available each year; the numbers present at each farm are given in Appendix 3. Nestboxes measured 14.5 x 14.8x21.0 cm with a 3.8 cm entrance hole diameter. Field routine.— I checked all nestboxes at intervals of 3 or 4 days throughout the breeding season. This pattern of visitation generally permitted accurate determination of dates of egg laying, hatching, nest losses and young birds leaving the nest. Nest contents were recorded at each visit and mass of eggs or young were taken using a Pesola spring scale. Eggs were numbered and mass measured to the nearest 0.1 g. Nesding mass was measured to the nearest ' Research Associate, Museum of Natural History, University of Kansas, Lawrence, Kansas 66045, and (present address) Assistant Professor, Department of Biology, Univer- sity of Northern Iowa, Cedar Falls. Iowa 50614. OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY :T7 FiGURh L— Location of study farms in southwestern Leavenworth County, Kansas. Farms are identified by landowner's name; cross hatching indicates woodland, stipple shows crop lands, and the remaining areas were u.sed as pasture or meadow. BREEDING BIOLOGY OF HOUSE SPARROWS 3 0.25 g. When nestlings reached 10-15 g, they were banded with num- bered and colored bands. Initial data tabulation.— For each clutch I recorded dates of egg laying, hatching and when young left the nest. In addition I noted number of eggs laid, number hatching and number of young surviving nestbox life. Mass of young birds 7 days old was determined to the nearest 1 g, either directly from measurements at age 7 days or by estimation using linear regression from measurements taken at ages bracketing 7 days. Nestling period is usually about 14 days, and at 7 days mass of young is slightly above the inflection point of a logistic growth curve (see Dawson, 1972: Fig. 27; Weaver, 1943: Table 1). I examined the following variables for interfarm variation: clutch size, egg mass, hatching success, survival of young, growth rates of young and lengths of incubation and nestling periods. At each farm in 1977 and 1978, I noted number of livestock present and I determined areas of croplands, meadows/pastures, and woods within 0.5 km. Statistical testing followed the procedures and methods outlined in Sokal and Rohlf (1981). Analyses of variance (pp. 211-213) or t-tests (p. 226) were used to compare groups for differences in mean values. Chi- square analyses (p. 703) were used to test for similarity in clutch size distribution between farms or to compare mortality patterns between farms. Spearman rank correlations (p. 607) were used to measure degree of association between variables. DEFINITIONS Initiated clutches.— One or more eggs laid in a nest; this includes completed clutches as well as clutches not completed. Total clutches initiated gives the number of nesting attempts in a broad sense. Completed clutches.— Clutches known to be incubated (and often hatching young) and/or including a "last laid egg." The last egg of a clutch frequently has less dense and less intense pigmentation spotting than other eggs of the clutch (see also Dawson, 1964:187; Seel, 1968:270). Nesting activity.— The number of clutches initiated per 20 active nestboxes. A nestbox was considered active if at least 1 clutch was initiated in it. Number of young hatching.— Because frequently there were missing eggs and/or young noted on the first visit following hatching, two designations for number of young hatching were recorded: maximum hatching assumes that the missing eggs hatched and dead young were removed by parents; minimum hatching assumes that the missing eggs did not hatch. Hatching success.— For completed clutches only, minimum number hatching divided by the number of eggs laid. Survivorship of young.— For completed clutches only, number of 4 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY young presumed or known to have survived to leave the nest divided by the minimum number of young known to have hatched. Egg survival.— For completed clutches only, number of young that left the nest divided by the number of eggs laid, i.e., the product of hatching success and survivorship of young. Incubation period. — The number of days between the laying of the penultimate egg until the first young hatched. This definition contrasts with usual definitions of incubation. Nestling period.— The number of days between the date the first young hatched and the last young left the nest. Interbrood interval.— The number of days between the date the last young leaves the nest and the first egg of the following clutch appears. Total nesting season.— Number of days between the t~irst completed clutch and the last completed clutch at a farm, measured from the dates the first eggs of each clutch were laid. Successful nesting season.— Number of days between the first and last completed clutches at a farm which successfully reared young, measured from the dates the first eggs of each clutch were laid. RESULTS Table 1 summarizes the results of statistical testing for differences between farms. There is much variation among these variables (see Appendices and Lowther, 1979), but only egg mass and pattern of mortality consistently showed significant between-farm differences for each year of the study. Mortality in the nest was most evident in hatching success rather than in the survival of young that did hatch. The distribu- tion of clutch sizes in 1975 showed very highly significant differences among farms, but for the other years of study no between farm dif- ferences were evident. There were no significant correlations between House Sparrow nest- ing success and area of any land type surrounding farmsteads. Egg mass, hatching success, 7-day mass of young, and interbrood interval showed significant between farm differences in 1978, but only hatching success (with r^ = 0.79, P<0.05) and interbrood interval (with r^= -0.75, Table 1 . Results of tests for significant differences between study farms for each year of study. Analysis of variance (F) and contingency X- (X-) tests were used to detect between farm differences. Variable Test 1975 1976 1977 1978 Egg mass F * *** *** *** Clutch size X2 *** ns ns ns Incubation period F ** ns ns ns Egg and nestling mortal ity X2 *** ** ** ** Nestling 7-day mass F — — ns ns Nestling period F — — * ns ns, not significant; *, P<0.05; **, P<0.01; ***, P<0.001 BREEDING BIOLOGY OF HOUSE SPARROWS 5 P<0.05) had significant rank correlations with number of livestock present. The relationship between total seasonal production (young/ nestbox) with livestock present is shown in Fig. 2. The North farm is an outlier that prevents a significant correlation. The Wiley farm 1977-1978 comparisons.— Experiments to inten- tionally manipulate farming practices were not possible. However, one "experiment" was done for me at the Wiley farm. This farm was ranked low in nesting activity for the 1977 season. However, in fall 1977 (and for most of 1978), an additional 30 hogs were kept at the farm and several litters of pigs raised. Clutches completed per nestbox increased from 2.13 to 3.13 (t = 2.75, P<0.01), with corresponding increases in eggs laid (from 10.5 to 16.0 eggs/nestbox) and young reared (3.50 to 6.73 young/ nestbox). The successful season was more than twice as long (42 days versus 114 days). Egg survivorship was somewhat but not significantly greater (33% versus 42%, X2 = 3.20, P<0.1); hatching success did differ significantly between years (X-= 15.26, P<0.001) and survivor- (/) if) UJ O o CO o z ID o >■ 8 - 6 - 2 - NORTH SWEARINGEN I FARMER HEMPHILL WILEY BRUNE —I 1 1 1 1 1 r— 20 40 60 80 LIVESTOCK NUMBERS 100 Figure 2.— Relationship between seasonal production of young from nests successfully rearing any young and numbers of livestock present at study farms. For 1977 (closed circles), r = 0.58. 0.2>P>0.1; for 1978 (open circles), r = 0.32, 0.5>P>0.2; for both years, r = 0.42, 0.2>P>0.1. Without the North farm, both years together, r = 0.75, P<0.(X)5; after 23 May 1978, 35 cattle were pastured at the North farm. 6 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY ship of young did not (X-=1.09, P<0.5). In 1978, 7-day old young were about 2 g heavier; eggs, however, were lighter. Other aspects of sparrow nesting biology did not differ between the two years (Table 2). DISCUSSION This study began as Edward Murphy's effort to compare life history traits of two populations of House Sparrows known to be different in their morphology (Murphy, 1977, 1980). Because of a desire for large sample sizes, nestboxes at the Vaughn farm were moved to other sites since only 6 clutches were completed in 1975. As I continued the Kansas portion of the original study, I focused my attention on the differences between sparrow colonies at these study farms and began to measure those aspects of farming I felt influenced House Sparrow breeding success. In retro- spect, continued monitoring of the sparrow colony at the Vaughn farm would have been a good idea. Most population studies of House Sparrows in North America (Weaver, 1943; North, 1968; Will, 1973; Anderson, 1978; Mitchell et al., 1973; Sappington, 1977; Pitts, 1979) have not looked at between- colony differences. Murphy (1977, 1978) pointed out between-farm differences at the same farms of this study from 1975 and 1976 data. He obtained significant F-values in nested analyses of variance, but did not describe these differences in detail; his impressions for the cause of Table 2. Comparison of House Sparrow productivity at the Wiley farm between the years 1977 and 1978. *, P<0.05: **. P<0.01. Variable 1977 1978 Number of nestboxes 16 15 Clutches initiated 42 50 Clutches completed 34 47 Clutches completed/nestbox 2.13 3.13 t = 2.75** Eggs laid (completed clutches) 168 240 Mean clutch size 4.94 5.11 t = 0.86 Eggs laid/nestbox 10.50 16.00 t = 3.02** Young surviving 56 lOI Egg survivorship (%) 33 42 X^ = 3.20 Young produced/nestbox 3.50 6.73 t = 2.36* Date of first clutch 21 Mar 4 Apr Date of first successful clutch 12 Apr 5 Apr Length of successful season (days) 42 114 Length of total season (days) 115 115 Mean egg mass (g) 2.96 2.90 t = 2.18* Mean interbrood interval (days) 8.55 7.86 t = 0.47 Mean incubation period (days) 12.20 11.65 t=1.46 Mean nestling period (days) 13.00 14.10 t=l.ll Mean 7-day mass, 4 young broods (g) 18.0 19.9 t = 2.40* BREEDING BIOLOGY OF HOUSE SPARROWS 7 differences in sparrow nesting activity was the between farm differences in insect populations (maintained by livestock). The data from 1975 differ in some respects from the data for later seasons. Mean clutch size, clutches per nestbox, and nesting activity were lower than in subsequent years and egg survivorship was higher than in other years (Fig. 3, Appendix 3). I believe that 1975 was peculiar because of the late placement of nestboxes at farms and an initial reluctance of birds to use them. Newly placed nestboxes were not readily used, especially at farms where boxes were put up early in spring (rather than the preceding fall). During later years, when boxes were added to a farm's complement, new boxes were used later than neighboring nest- boxes. The addition of many, new, safe nest sites possibly interfered with the established social structure of House Sparrows at these farms and nestboxes in 1975 were used more by first year birds. The smaller clutch size and later start to the nesting season both support this suggestion. For many bird species, first time breeders have smaller mean clutch size and begin egg laying later than older, experienced breeders (Klomp, 1970). Summers-Smith (1958) reported that House Sparrows begin nest site selection in January and February and that older birds (e.g., those that have bred previously) commonly retain nest sites that they have used before (see also Daanje, 1941; Deckert, 1969). I found interbrood interval, 7-day mass, hatching success and egg mass to differ significantly between farms. One explanation for these differences is the availability of food. If food is readily available, females can quickly adjust to egg laying (and have a shorter interbrood interval), form heavier eggs, need shorter absences from the nest for feeding themselves (and greater hatching success) and more easily rear healthy (heavier) young. Experimental studies that have provided supplemental food to nesting birds have enhanced reproductive success in some of these same ways (Kiillander, 1974; Yom-Tov, 1974; Crossner, 1977; Hog- stedt, 1981). Two House Sparrow studies have shown enhanced repro- ductive success that was attributed to increased food resources. Anderson (1977) found that House Sparrows breeding during an emergence year of periodical cicadas (Magicicada spp.) had shorter interbrood intervals, heavier young and greater survival of young when compared with other years without a superabundant source of food. Dawson (1972) compared a village sparrow colony with a farm colony. The farm birds, with greater food resources, had shorter interbrood intervals, larger clutches and (in early June) the 10-day mass of young was greater. Both Pitts (1979) and Encke (1965) reported rural sparrow populations to have larger clutch sizes in rural-urban comparisons. (Encke's two sites were 250 km apart and studied in different years.) House Sparrows and Farms House Sparrows established themselves first in cities (Barrows, 1889). The decline of horse-drawn transportation was the probable cause of House Sparrows' switch from cities to farms as preferred habitat OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY on C/5 3 rj Li. 3 BJ ?0 II ft ~0Q ^ < <» c ^ 3 O ■ ^ o (-^ ft c D. EGG SURVIVAL ■n II on 00 m ft X II K 3 ■a 3- ro -t^ a> 1 1 II 1 1 CO ro. O o b o o • \ w \ - V " en o" \ • " %' ^ C/5 CD. o 1 1 -L*-n \ •z l_ 1 o o X m > CD. H - m o ■V m ro -p' o sx II o o • 1975 Oi o < o -t^ • -n • ^ • • a3» I -n • ■ 1 1 J 1 ro 1 1 1 1 "T— — 1— O - "0 "^ ^_ - > o o (0 HO — O) U) < o ^ m . - z \ m-^. • \ coO CD \ H \ O \ . (/5 - X \ • C/50' \ •• X - *\ GO ) \^(n O z 1 • \: L_ 03 II CD 5 s n BREEDING BIOLOGY OF HOUSE SPARROWS 9 (Eaton, 1924; Rand, 1965). Dyer et al. (1977) reported that House Sparrow densities are highest— 1200-1300 birds/km-— about human dwellings especially in association with livestock. Highest densities of sparrows in North America (see Robbins, 1973) are also the major areas of grain (corn, wheat, and oats) and livestock (swine and cattle) produc- tion. Land use around farms could have some influence on House Sparrow breeding since House Sparrows are quite sedentary, especially during the breeding season. Summers-Smith (1963) reported that breeding birds forage within 200 m of their nests; Dawson (1972) seldom saw flights of more than 100 m from the nest. For this reason land within 0.5 km of nesting sites would have most influence on nesting success. The annual cycle of House Sparrows includes a period of fall flocking, foraging, and dispersal. Young birds, as they become independ- ent of parental care, begin to gather together into flocks. In Kansas, these flocks are noticeable in late July and August along the edges of sorghum and wheat fields. Since these crops do not ripen until late in the nesting season, these fields indirectly influence food abundance. Nearby crop- lands promote dispersal and thus maintain nesting populations; stored grain at farmsteads may aid overwinter survival. The Wiley Farm 1977-1978 Comparisons The Wiley "experiment" resulted in more nesting attempts during 1978 (see Table 2). Although egg survival did not change, increased nesting activity meant that each nestbox (and presumed pair) produced more young. This difference between 1977 and 1978 seemed a direct response to the 30 hogs fed overwinter and bred during 1978. Conditions at the Brune farm contrast with those at the Wiley farm: no cattle were fed overwinter 1977-1978 and only a few animals were pastured in surrounding fields for a short time in 1978. Between farm comparisons suggest that date of first clutch, length of nesting season, hatching success and interbrood interval vary in a manner consistent with probable availability of food. Between year comparisons at the Wiley farm provide some additional support for these associations. In 1978. the first successful clutch at the Wiley farm was laid earlier than in 1977, even though the 1978 spring began later. Length of the nesting season for both years was the same but the time interval for successful clutches was very short in 1977. Hatching success between the two years was significantly different; but there was no difference in survivorship of young between the two years {X^=\.09, df=l, 0.5>P>0.1). Mean interbrood interval was slightly smaller in 1978, an expected response with abundant food. CONCLUSIONS In the course of rearing young, a female House Sparrow will lose a large fraction of her mass; Pinowska (1979) reported a mean mass of 34 g for females laying eggs and 28 g after rearing young. Protein metabolism 10 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY increases during egg laying (Pinowska, 1979) and protein reserves may actually limit clutch size for some species at least (Jones and Ward, 1976). Laying female House Sparrows eat more insects (Pinowska, 1975) for the protein needed for egg production. The between farm differences I found in this study seem related primarily to food factors affecting the well-being of egg laying females. Female House Sparrows have a cyclic change in mass during each nesting attempt: an initial gain in mass for egg laying followed by a gradual loss of mass as young are reared (Pinowska, 1979; pers. obs.). Birds adjust physiologically for subsequent nesting cycles. First clutches in spring are laid when females get into breeding condition. The length of the nesting season at a location reflects how long conditions remain favorable for continued egg laying. During incubation, females build up the fat reserves which were lost during egg laying (Pinowska, 1979). If this is not easily done, hatching success may suffer owing to prolonged absences by the female. ^ 1 taKU ^ b Wt i -I 500 - 400 300 200 - 100 75 76 77 78 FARMER 75 76 77 78 WILEY 75 76 77 78 SKEET 75 76 77 78 HEMPHILL ^ i 1 1 1 ?§? S2 300 200 100 75 76 77 78 BRUNE 76 77 78 SWEARINGEN 76 77 78 NORTH 75 76 F WILEY 75 VAUGHN Figure 4.— Survivorship of completed clutches at study farms for each year of observation. Actual numbers of eggs and young are shown. Open bars = total eggs laid, cross hatch- ing = maximum number of young hatching, diagonal lines = minimum number of young hatching, stipple = number of young surviving. See also Fig. 5. BREEDING BIOLOGY OF HOUSE SPARROWS II FARMER WILEY SKEET HEMPHILL 75 76 77 ro ro PO en * u) to 00 o (0 75 76 77 78 75 76 77 78 75 76 77 78 75 76 77 78 PO PO o ->i — PO 0) — — PO 01 00 0) ^ X> ■t' 00 o (jl 00 00 o PO PO PO t. U\ t^ wo*. 10 PO (J) 3R JNE SWEARINGEN NORTH F WILEY VAUGHN 76 77 78 PO PO ro — (j> -J — ->i * 76 77 78 ro Ctl w Jk ro o tn -u 75 76 00 ^ PO (J\ 75 o Figure 5.— Survivorship of completed clutches at study farms for each year of observation. Proportionate numbers of eggs and young are shown. Open bars = total eggs laid ( = 100%), cross hatching = maximum number of young hatching, diagonal lines = minimum number of young hatching, stipple = number of young surviving. Numbers below year designation indicate total number of eggs laid. See also Fig. 4. SUMMARY The breeding biology of House Sparrows was studied at nine farms in northeastern Kansas for four years (1975-1978). Study farms showed differences in overall productivity and intensity of nesting activities. Nearby land uses showed no relationships with sparrow nesting activity. Between farm differences in date of first clutches, length of nesting season, interbrood interval, and length of incubation period exist and seem to be caused by differences in food reserves at farms. The presence of farm animals is an important component of optimal House Sparrow 12 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY habitat, since feedlot conditions encourage many insect populations, which serve as protein sources for egg laying females and growing nestlings. Differences between farms in food resources determine how quickly females adjust to lay eggs but were not sufficient to cause noticeable differences in growth rates or survivorship of young. ACKNOWLEDGMENTS I give special thanks to Edward C. Murphy for his initial work in organizing this research. From Richard F. Johnston and Calvin L. Cink, I learned an appreciation of House Sparrow biology and received encour- agement for all aspects of this study. Welcomed company and assistance during field routines were provided by Caryn T. S. Lowther, John E. Bucher, Jeffrey A. Cox, James L. Rakestraw, and W. Bruce McGil- livray. I am grateful to the landowners who permitted placement of nestboxes on their farms: Daniel Farmer, Francis Wiley, Othal Wiley, Harry Skeet, Arthur C. Hemphill, Frank Brune, Thomas H. Swearingen, Lena North and Cleve B. Vaughn. Banding was done under the auspices of the Bird Banding Laboratory, U.S. Fish and Wildlife Service. Initial funding of this project was provided by the National Science Foundation through grants DEB 72-02374 and BMS 76-02225 and continued by General Research Fund grants from the University of Kansas. LITERATURE CITED Anderson, T. R. 1977. Reproductive responses of sparrows to a superabundant food supply. Condor 79:205-208. . 1978. Population studies of European sparrows in North America. Occ. Papers Mus. Nat. Hist., Univ. Kansas, No. 70. Barrows, W. B. 1889. The English Sparrow in North America, especially in its relations to agriculture. U.S. Dpt. Agri., Div. Econ. Ornith. Mammal. Bull. 1:1-405. Crossner, K. a. 1977. Natural selection and clutch size in the European Starling. Ecology 58:885-892. Daanje, a. 1941. Uber das Verhalten des Haussperlings (Passer d. domesticus (L.)). Ardea 30:1-42. Dawson. D. G. 1964. The eggs of the House Sparrow. Notornis 11:187-189. . 1972. The breeding ecology of House Sparrows. D.Phil, thesis, Oxford. Deckert, G. 1969. Zur Ethologie und Okologie des Haussperlings (Passer d. domesticus L.). Beitr. Vogelk. 15:1-84. Dyer, M. I., J. Pinowski, and B. Pinowska. 1977. Population dynamics, pp. 53-105. In J. Pinowski and S. C. Kendeigh (eds.), Granivorous birds in ecosystems. Cambridge Univ. Press, Cambridge. Eaton, W. F. 1924. Decrea.se of the English Sparrow in eastern Massachusetts. Auk 41:604-606. Encke, F.-W. 1965. iJber Gelege-, Schlupf- und Ausflugsstarken des Haussperlings (Passer d. domesticus) in Abhangigheit von Biotop und Brutperiode. Beitr. Vogelk. 10:268-287. HoGSTEDT, G. 1981. Effect of additional food on reproductive success in the Magpie (Pica pica). J. Anim. Ecol. 50:219-229. Johnston, R. F., and W. J. Klitz. 1977. Variation and evolution in a granivorous bird: the House Sparrow, pp. 15-51. In J. Pinowski and S. C. Kendeigh (eds.), Granivorous birds in ecosystems. Cambridge Univ. Press, Cambridge. BREEDING BIOLOGY OF HOUSE SPARROWS 13 Jones. P. J., and P. Ward. 1976. The level of reserve protein as the proximate factor controlling the timing of breeding and clutch-size in the Red-billed Quelea Quelea quelea. Ibis 115:547-574. Kallandfr. H. 1974. Advancement of laying of Great Tits by the provision of food. Ibis 116:365-367. Klomp. H. 1970. The determination of clutch-size in birds. A review. Ardea 58:1-124. LowTHER. P. E. 1979. Interfarm variation in breeding biology of a Kansas population of House Sparrows (Passer domesticus). Ph.D. diss., Univ. Kansas, Lawrence. Mitchell, C. J.. R. O. Hayes, P, Holden, and T. B. Hughes, Jr. 1973. Nesting activity of the House Sparrow in Hale County, Texas, during 1968. Ornith. Monogr. 14:49-59. Murphy, E. C. 1977. Breeding ecology of House Sparrows. Ph.D. diss., Univ. Kansas, Lawrence. . 1978. Breeding ecology of House Sparrows: spatial variation. Condor 80:180- 193. . 1980. Body size of House Sparrows: reproductive and survival correlates. Acta XVII Cong. Intern. Ornith., 1155-1161. North, C. A. 1968. A study of House Sparrow populations and their movements in the vicinity of Stillwater, Oklahoma. Ph.D. diss., Oklahoma State Univ., Stillwater. PiNOWSKA, B. 1975. Food of female House Sparrows (Passer domesticus L.) in relation to stages of the nesting cycle. Pol. Ecol. Stud. 1:211-225. . 1979. The effect of energy and building resources of females on the production of House Sparrow (Passer domesticus (L.)) populations. Ekol. Polska 27:363-396. Pitts, T. D. 1979. Nesting habits of rural and suburban House Sparrows in northwest Tennessee. J. Tennessee Acad. Sci. 54:145-148. Rand, A. L. 1956. Changes in English Sparrow population densities. Wilson Bull. 68:69-70. RoBBiNS, C. S. 1973. Introduction, spread, and present abundance of the House Sparrow in North America. Ornith. Monogr. 14:3-9. Sappington, J.N. 1977. Breeding biology of House Sparrows in north Mississippi. Wilson Bull. 89:300-309. Seel, D. C. 1968. Clutch-size, incubation and hatching success in the House Sparrow and Tree Sparrow Passer spp. at Oxford. Ibis 110:270-282. SoKAL, R. R., and J. F. Rohlf. 1981. Biometry, 2nd ed. W. H. Freeman and Co., San Francisco. Summers-Smith. D. 1954. Colonial behaviour in the House Sparrow. British Birds 49:249-265. . 1958. Nest-site selection, pair formation and territory in the House-sparrow Passer domesticus. Ibis 100:190-203. 1963. The House Sparrow. Collins, London. Weaver, R. L. 1943. Reproduction in English Sparrows. Auk 60:62-74. Will, R. L. 1973. Breeding success, numbers, and movements of House Sparrows at McLeansboro, Illinois. Ornith. Monogr. 14:60-78. YoM-Tov, Y. 1974. The effect of food and predation on breeding density and success, clutch size and laying date of the crow (Corx'us corone L.). J. Anim. Ecol. 43:479-498. 14 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY Appendix 1. Clutch size distributions for all s tudy farms for each year of study. 1 Data for 1975 and 1976 from E. C. Murphy (unpubl. tl ield notes) Year Clutch size Mean SD N 1 2 3 4 5 6 7 8 Farmer 1975 2 4 18 13 5 5.36 0.98 42 1976 9 24 28 11 5.57 0.90 72 1977 2 6 33 19 9 5.39 0.93 69 1978 3 8 29 21 7 5.31 0.97 68 Wiley 1975 6 4 5.40 0.52 10 1976 5 22 9 5.11 0.62 36 1977 4 6 13 10 1 4.94 1.04 34 1978 1 7 25 14 5.11 0.73 47 Skeet 1975 1 1 2 23 16 2 5.29 0.89 45 1976 1 7 18 23 3 5.38 0.87 52 1977 2 8 22 12 2 5.09 0.89 46 1978 1 6 17 14 1 5.18 0.91 39 F. Wiley 1975 1 12 3 5.13 0.05 16 1976 1 2 3 2 1 5.00 1.22 9 Vaughn 1975 1 3 2 5.00 1.10 6 Hemphill 1975 1 2 14 21 8 4.72 0.89 46 1976 3 21 30 28 4 5.10 0.95 86 1977 2 3 20 38 31 5 1 5.12 1.05 100 1978 2 15 41 23 4 1 5.17 0.90 86 Brune 1975 2 6 15 29 7 4.56 0.95 59 1976 3 8 22 15 1 5.06 0.90 49 1977 1 2 8 28 16 2 5.09 0.93 57 1978 1 3 5 12 9 2 4.97 1.18 32 Swearingen 1976 1 9 18 14 5.02 0.98 42 1977 1 1 4 32 12 2 5.13 0.84 52 1978 2 7 26 16 2 5.17 0.85 53 North 1976 1 8 23 14 1 5.13 0.80 47 1977 1 2 6 39 14 2 5.08 0.84 64 1978 1 1 9 28 17 3 5.15 0.93 59 BREEDING BIOLOGY OF HOUSE SPARROWS 15 Yearly totals 1975 4 12 36 112 33 7 4.98 0.95 224 1976 1 9 69 160 133 21 5.21 0.90 393 1977 5 16 58 205 114 23 1 5.14 0.94 422 1978 3 12 57 178 114 19 1 5.17 0.91 384 Total (all 4 years) 1 12 49 220 655 414 70 2 5.14 0.93 1423 Appendix 2. Between year comparisons of mortality patterns at each study farm. X- contingency table is used to test for differences in mortality of eggs and young. Eggs lost = difference between eggs laid and minimum young hatching; young lost = difference between minimum young hatching and young surviving. Compare with Figures 4 and 5. *. P<0.05; **■ P<0.01. Study farm 1975-1976 1976-1977 1977-1978 Farmer 4.40* 12.28** 28.88** Wiley 3.36 27.63** 12.99** Skeet 42.13** 12.32** 1.79 Hemphill 1.16 21.76** 0.02 Brune 2.18 2.20 12.55** Swearingen — 0.09 9.42* North — 1.26 0.37 16 OCCASIONAL PAPERS MUSEUM OF NATURAL HISTORY §^ c3^ S 'Xi 1) o c 2 OJ '•^m -o > sz Cu L- 3 5 u ui f~ _C c CJ o t. _3 ^^ O CA ON Ur ""^ '£ -o c CO ir> [^ o ^— k- c* o c t+i 3 3 O >- a >% c -a CXj-- 3 .ss v5 jr C^H a _ O CO CO = s u >. j= u ca CA 1) W) o c^ o: E ^ .=^ 4_, rj CO V3 > 3 ■^ U o a 00 c y5 ■u c o to 1) OJ X p>1 CO Zi E E 3 00 r<-i X L« a CO z . It a. E ^ a. 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C « ."3 c — TO c o to c 3 *- ■ — ' c^ 0^ '^ c > > 00 CJj c c E E _3 _3 o o O r- '-^ n> -= "3 'i 00 1> ?3 C •■« ■O ii 60 j^, V5 .E 0-> Ql •-* > > ^ oo Si, c O O '■*- u o O V) w: cy5 c/D (/^ c ^ u ^M ^VO t^ 00 NO r- 00 .5 I— t^ r- r- r- r- 1;; o (U On ON sz ON ON ON \r. ' — ' ' ' u — ' ' ' OJ ? c O on Z z U. U. UL. [1- [I- T3 — ri r^, Tt m University of Kansas Publications MUSEUM OF NATURAL HISTORY The University of Kansas Publications. Museum of Natural History, beginning with volume 1 in 1946, was discontinued with volume 20 in 1971 . Shorter research papers formerly published in the above series are now published as Occasional Papers, Museum of Natural History. The Miscellaneous Publications, Museum of Natural History, began with number 1 in 1946. Longer research papers are published in that series. Monographs of the Museum of Natural History were initiated in 1970. All manuscripts are subject to critical review by intra- and extramural specialists; final acceptance is at the discretion of the publications committee. Institutional libraries interested in exchanging publications may obtain the Occasional Papers and Miscellaneous Publications by addressing the Exchange Librarian, The University of Kansas Li- brary, Lawrence, Kansas 66045. Individuals may purchase separate numbers of all series. Prices may be obtained upon request addressed to Publications Secretary, Museum of Natural History. The Univer- sity of Kansas, Lawrence, Kansas 66045. Editor: E. O. Wiley Managing Editor: Joseph T. Collins PRINTED BY university of KANSAS PRINTING SERVICE LAWRENCE. KANSAS 7 (J 7 0 I \k 3 2044 093 361 699 DATE DUE ARR^i-^fe04 DEMCO, INC. 38-2931