1Archaeology, UCL, 2Anthropology, Smithsonian Institution National Museum of Natural History
April 18, 2020 , Platinum Ballroom
The phenotypic impact of anthropogenic pressures upon primates is increasingly prevalent, yet remains disproportionately understudied. Captive environments can pose unique pressures based on factors like physical activity levels and caloric availability; thus, maturation patterns should vary under differing captive conditions. The development and growth of two Macaca mulatta populations, under different levels of human management, were analyzed to assess the impact of anthropogenic environments on captive primates. To track development, we scored 13 epiphyseal fusion locales across long bones in a skeletal sample of lab-reared M. mulatta (n=154), including the right tibia, femur, humerus, ulna and radius. We employed a three-tier scoring system, consisting of “0” (unfused to diaphysis), “1” (fusing) and “2” (fused). To record growth and body size, we collected 29 linear measures of these long bones, taken via digital calipers to the nearest 0.1mm. Means and standard deviations were generated to compare samples; t-tests were used to determine significant differences between means. These values were compared to available data on the free-ranging, provisioned M. mulatta population of Cayo Santiago. The free-ranging monkeys (n=277) were found to exhibit larger postcranial lengths (p<0.05) and widths (p<0.05) than lab-reared specimens. Although larger limb bones are usually associated with delayed development, earlier epiphyseal fusion (up to 2.53 years) was also documented among free-range monkeys. These observations may reflect accelerated development resultant of a protein-rich diet provided to free-ranging monkeys, and may also reflect hindered growth caused by restricted movement experienced by lab-reared monkeys.