Abstract # 9:

Scheduled for Thursday, June 21, 2007 11:15 AM-11:30 AM: Session 1 (North Main Hall C/D) Oral Presentation

Dads Don't Pay for Sex but Do Buy the Milk: Food Sharing and Reproduction in Owl Monkeys (Aotus nancymaae)

C. K. Wolovich1, S. Evans2 and J. A. French3
1University of Miami, Department of Biology, Coral Gables, FL 33124-0421, USA, 2DuMond Conservancy for Primates and Tropical Forests, Inc., 3University of Nebraska
     Sharing food is costly and it is rare among unrelated individuals. Males may share food with unrelated females when that food may indirectly aid their offspring. Such benefits are known for insects and birds, but not for mammals. We examined the effect of female reproductive state (ovarian cycling; pregnancy; lactation) on food sharing between mates in the monogamous owl monkey, Aotus nancymaae. Male-female pairs (n=7) of captive owl monkeys at the DuMond Conservancy (Miami, FL USA) were regularly observed feeding from Oct 2003 – Nov 2004. To determine the onset and duration of pregnancy, urine was collected from females and analyzed for pregnanediol-3a glucuronide using enzyme immunoassay. Food transfers from females to males did not vary according to reproductive state [Friedman’s c2 =0.1, p=0.946]. Conversely, females most often begged for food when they were lactating [Friedman’s c2 =6.4, p=0.043], and males most often transferred food to their mates when they were lactating [Friedman’s c2 =7.7, p=0.021]. We found a significant negative relationship between the rate of transfers to females and interbirth intervals [Spearman’s Rank Order Correlation, r=-0.81, p<0.05], suggesting a potential effect of food sharing on reproductive success. Because owl monkeys are monogamous and males are relatively certain of paternity, they would benefit from ensuring that their mates receive adequate nutrition especially when it indirectly provides nutrition for offspring.