The mating system of the California ground squirrel, Spermophilus beecheyi, was examined to determine the incidence of multiple paternity of litters and the circumstances under which it occurs. The population studied has a promiscuous mating system. All receptive females solicited and mated with multiple males, which resulted in 88.9% (eight of nine) of litters sampled in 1988 being multiply sired, the highest frequency of multiple paternity yet reported for a natural population of any species. Five proteins in blood samples of adults and litters were tested by polyacrylamide gel electrophoresis and isoelectric focusing for the analysis. Males defended territories that partially overlapped home ranges of females, but did not achieve exclusive access to those females. Females travelled from their home burrows to mate bot h with males whose home ranges partially overlapped their own and with males whose home ranges did not overlap with their own. Females ma ted with an average of 6-7 males during receptive periods that averaged (±sd) 6-67+3-18 h in duration.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology