PETTITT, Beth*; WATERMAN, Jane M; University of Central Florida; University of Central Florida: Reproductive suppression in female Cape ground squirrels, Xerus inauris

Cooperative breeding is common among social animals and is characterized by group members that exhibit delayed dispersal from natal group, reproductive suppression, and alloparental care. Mechanisms of reproductive suppression may be mediated through the presence of breeding females, exposure to males and/or resource levels. Initial field studies of Xerus inauris indicate evidence for reproductive delay as first estrus of sub-adult females differs with number of adult breeding female group members. We investigated reproductive suppression in free-ranging female X. inauris by examining behavior and hormone profiles of pre-reproductive and reproductive females to verify inhibition of sexual maturity. Correlations between progestogen profiles and group structure were examined to infer possible mechanisms of inhibition. Preliminary results suggested that reproductive suppression in female Cape ground squirrels is mediated at multiple levels. Reproductive suppression may be costly for dominant breeding females as their reproductive success decreased with increasing group size.