Louis W. Botsford, Dale F. Lott, John G. Brittnacher, and Sonke Mastrup
Department of Wildlife and Fisheries Biology
University of California
Davis, CA 95616
Lack of a detectable dependence of recruitment on density in hunted populations of California quail (Callipepla californica) led us to examine an unhunted population on Santa Cruz Island for this characteristic. We have estimated juvenile -to-adult ratios and an index of abundance near the beginning of August annually for the past 7 years (1987-93). Our sampling consists of two observers in each of two vehicles driving fixed transects and counting quail by age and sex for 3 days. The juvenile-to-adult ratio depends positively and significantly on precipitation from January through March (R=0.87, p<0.05). With the effect of precipitation removed, the juvenile-to-adult ratio declines with adult density (R=0.69, p<0.1). Although sample size is low, these data indicate reproduction in California quail may be density-dependent.
Santa Cruz Island Symposium, 1994