Mating tactics of male Cape ground squirrels, Xerus inauris: consequences of year-round breeding.
The Cape ground squirrel is a highly social, tropical ground squirrel that does not hibernate, suggesting that female receptivity could be scattered throughout the year. Males in this species are very social, living in all-male bands. I studied the mating tactics of male Cape ground squirrels to examine the effects of year-round female receptivity and male grouping on these tactics and on the degree of intrasexual competition. Female breeding was highly irregular and unpredictable, and the average operational sex ratio during oestrus was 10:1 (males to females). However, the predicted high rates of aggression were not observed. Instead, competition among males was manifested by competitive searching, repeated copulations and disruptions of copulations. Dominant males had more copulations with more females, first access to females and were more likely to copulate below-ground where disruptions were unlikely to occur. I conclude that the mating patterns of males in this species are a product of the asynchrony of female oestrus, year-round breeding and the survival benefits of grouping. Copyright 1998 The Association for the Study of Animal Behaviour
Waterman
JM
Department of Ecology, Evolution and Behavior, University of Minnesota