Abstract # 50:

Scheduled for Thursday, August 18, 2005 07:00 PM-09:00 PM: (Cambridge/Oxford Room) Poster Presentation

Female Age-Specific Reproductive Rates, Birth Seasonality, and Infant Mortality of Ringtailed Lemurs (Lemur catta) on St. Catherines Island, USA

J. A. Parga1 and R. G. Lessnau2,3
1University of Texas at Austin, Department of Anthropology, 1 University Station C3200, Austin, TX 78712, USA, 2Wildlife Conservation Society, St. Catherines Island Wildlife Survival Center, 3Armstrong Atlantic State University
     We analyzed birth and mortality records collected over the 17-year history of the St. Catherines Island Lemur catta colony to compare reproductive parameters of females in this colony to wild L. catta. The majority (80%) of births (n = 147) occurred in March, indicating that most females conceived during the first estrus cycle of the breeding season. Although the typical primiparous age for wild L. catta is three, females in the island colony began giving birth at age two. Infant mortality was lower (28.6%) than reported infant mortality in the wild (between 37-80%). Although multiple-offspring births are exceedingly rare in Madagascar, 1 triplet and 18 twin births were recorded on St. Catherines. Fecundity was lowest (34%) at the maternal age of 2 years, but increased to 67-100% for females three and older. Survival analysis revealed that survivorship for infants born to very young (2-3 years) and old (10 years and older) mothers was lower (60%) than that for reproductively prime-aged females between 4-9 years of age (70%), though this difference was not statistically significant (χ2 = 3.18, df = 2, n = 125, P = 0.203). When compared to wild populations, female L. catta on St. Catherines began reproducing earlier, had lower infant mortality rates, and exhibited a greater number of multiple-offspring births. We largely attribute these differences to provisioning on St. Catherines Island.