Abstract # 3008 Event # 217:

Scheduled for Monday, September 19, 2011 10:40 AM-11:00 AM: Session 28 (Salon F (Sixth Floor)) Oral Presentation


REPRODUCTIVE SEASONALITY IN RELATION TO FOOD AVAILABILITY IN WILD FEMALE SANJE MANGABEYS, UDZUNGWA MOUNTAINS NATIONAL PARK, TANZANIA

G. M. McCabe
University of Texas at San Antonio, Department of Anthropology, One UTSA Circle, San Antonio, Texas 78249, USA
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     Reproductive timing in primates has been correlated with high food availability. Among cercopithecines, periods of food abundance have been linked to one of two critical phases: conception or lactation. In the former, also known as the classic pattern, an increased food supply supports a positive energy balance for females, maximizing the potential for conception which may increase the chances of successful pregnancy. This study examines the relationship between seasonality of food availability and timing of reproductive events in the Endangered Sanje mangabey (Cercocebus sanjei). Reproductive data were collected from September 2008 through February 2011. The timing of conceptions and births (n=31) was compared to total monthly rainfall and fruit availability. Conceptions occurred throughout the year; however, the distribution was non-uniform (Rayleigh test: z=5.518; p=0.003), with significantly more conceptions in the wet season (t = -2.546, p=0.04) compared to the dry season. Fruit availability was also found to be significantly higher in the wet season (t= 3.295, p=0.022, eta squared = 0.68). These findings indicate that Sanje mangabeys exhibit the classic pattern of primate reproduction, typical of closely related cercopithecines, such as Papio spp. This pattern may have evolved during a period in primate evolution where ecological conditions were unpredictable. As a result, selection occurred for a synchronization of conception with current energetic conditions, i.e., high food availability, over future periods in reproduction, such as lactation.