1Department of Anthropology, Stony Brook University, Stony Brook, NY, 2Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY
Friday 2:00-2:15, Galleria North
Comparative life history studies typically indicate that gorillas grow and reproduce more quickly than do other great apes, although this conclusion is primarily based on data from captivity and a single (Karisoke) population of eastern gorillas (Gorilla beringei) that reside where high-quality food is abundant. Since growth and reproduction are strongly influenced by nutrition, gorillas in habitats with less food may mature and reproduce more slowly. Here we document growth and reproduction in wild western gorillas at the Mondika Research Center, Republic of Congo. We followed one group on a nearly daily basis between 2002-2011, recording all births, deaths, immigrations and emigrations, and for a more restricted time period, all copulations and nipple contact to determine gestation and weaning age respectively. Although gestation lengths were comparable at both sites, at Mondika, gorillas weaned 33% later, inter birth intervals (following a surviving offspring) were 35% longer, and female age at natal transfer and first reproduction was 1.3 years later than at Karisoke. These results, together with data from three other gorilla sites, indicate considerable variation in gorilla growth and reproduction, with all gorilla populations, except Karisoke, growing and reproducing at a much slower pace than commonly assumed.
This study was funded by The Leakey Foundation, U.S. Fish and Wildlife, and the National Science Foundation.