THOMAS C. WAINWRIGHT, Department of Wildlife and Fisheries Biology, University of Califorina, Davis, CA 95616
JACK T. SMITH, California Department of Fish and Game, 1015 E. Adams Avenue, Los Banos, CA 93635
SONKE MASTRUP, Department of Wildlife and Fisheries Biology, University of California, Davis, CA 95616
DALE F. LOTT, Department of Wildlife and Fisheries Biology, University of California, Davis, CA 95616
Demographic responses of California quail (Callipepla californica) to precipitation-related variables vary among locations with different mean rainfall. With 23 years of data from a California quail population in a semiarid region, we determined a positive response of reproductive success (juv/ad) to precipitation during the previous winter. Computed correlations with soil moisture content and actual evapotranspiration were significant but not as high as with precipitation. Correlations with mean monthly temperature, days/month <O C, and days/month >38 C were not significant. Attempts to account for possible lower reproductive capability of first-year breeders did not improve statistical relationships. The number of adults each year was positively correlated with the number of juveniles in the previous year. The number of juveniles produced each year was correlated with the number of adults in that year only when the effect of precipitation was removed; the relationship was then linear. The interannual fluctuations in population numbers resulted from low adult survival and the influence of precipitation on recruitment through unknown mechanisms.
J. WILDL. MANAGE. 52(3):469-477, 1988.