Meeting Abstract

P2.94  Jan. 5  Fecal progestogen profiles of pregnant and lactating free-living Cape ground squirrels (Xerus inauris) PETTITT, Beth A.*; WATERMAN, Jane M.; University of Minnesota; University of Central Florida pettittbeth@yahoo.com

Few studies have addressed the role of hormones in reproduction in free-living mammals. This investigation established a normative endocrine profile for pregnancy and lactation for the cooperative breeding female Cape ground squirrel (Xerus inauris). The patterns of behavioral estrus and fecal progestogen concentrations were followed in free-living multiparous and primiparous Cape ground squirrels from two study sites in southern Africa. Behavioral observations and fecal samples were collected from 19 multiparous and 12 primiparous females from May-November 2004. All females showed a significant increase in fecal progestogen concentrations immediately following the day of the estrus and concentrations continued to rise until the day of parturition when progestogen dropped to non-pregnant levels. In the majority of pregnancies that resulted in successfully emerged offspring, females showed a second peak of fecal progestogen during lactation. This lactational peak may be adaptive if it prevents a post-partum estrus during the energically costly period of lactation. When offspring successfully emerged, gestation averaged 47.6 days, lactation averaged 67.8 days and time from estrus to emergence averaged 100.1 days. The results of this study indicate that fecal progestogen concentrations are useful indicators of pregnancy in Cape ground squirrels.