Proceedings of the Vertebrate Pest Conference

From the fall of 1977 through late spring of 1979, periodic examination of female ground squirrels in the low oak woodlands of southern Tulare County revealed that as much as 20 percent of the reproductively active females bred a second time within a given breeding season. This began to occur 50 to 80 days after the beginning of the breeding season. Evidence of litter loss from abortion was inapparent in 1979, but grossly obvious uterine inflammation was seen in 2 percent of the females in 1978. Neonatal losses were undetermined. Rebreeding appeared to occur in the older females, 2 years and older, and considering that older females probably constitute 35 percent of the breeding females, 20 percent breed-back would seem to be quite significant.