REPRODUCTIVE-BIOLOGY OF A TROPICAL, NON-HIBERNATING GROUND-SQUIRREL

To examine the effects of climate and hibernation on reproductive patt erns, I compared tropical and temperate species of ground and tree squ irrels. I studied the reproductive biology of a tropical species, the Cape ground squirrel (Xerus inauris), by observing marked individuals in the Kalahari-bushveld region in Namibia. Breeding occurred througho ut the year, although there was some seasonality. Interestrous interva ls were 76.5-146 days, gestation averaged 47.7 days, lactation average d 52 days, there were one to three litters per year, with litters of o ne or two young. Subadult males reached reproductive maturity at 8 mon ths, while females had their first estrus at 10 months. Comparisons of these reproductive trails with other species in the family Sciuridae suggest that reproduction in the Cape ground squirrel is influenced by a long active season in an unpredictable habitat. Of the potential fa ctors affecting reproduction in squirrels, I conclude that climate is the most critical, and nutrition, predation, and allometry are less im portant.