Marian Hamilton

MARIAN HAMILTON, then a graduate student at University of New Mexico, Albuquerque, New Mexico, was awarded funding in April 2016 to aid research on ‘Tracking Dispersal and Home Range Size with Environmental and Faunal Strontium Isotopes,’ supervised by Sherry Nelson. This project assessed whether strontium isotope ratios are reliable proxies for microhabitat preference (living in a riparian forest versus savanna-grasslands) or philopatric dispersal (whether males or females leave the group they were both in when they reach sexual maturity) using fauna from Kibale National Park and Toro-Semliki Wildlife Refuge in Uganda. Strontium isotope ratios derive from the underlying bedrock of an area, and animals assimilate the ratios of the food they eat. Therefore, strontium isotope ratios can tell you about where an animal was living and eating. Strontium isotope ratios differentiated between animals who preferred to live in the forest and those who live in the open savanna-grasslands at Toro-Semliki Wildlife Refuge. For philopatry patterns, offsets between tooth and bone isotope ratios were greater in members of the dispersing sex in small ranging monkey species in Kibale National Park, but not in chimpanzees. However, offsets between the local environment and tooth ratios were greater in members of the dispersing sex in chimpanzees and baboons, but not in other monkey species. This research suggests that strontium isotope ratios can be used to investigate habitat preference in fossils with high fidelity, but investigating philopatry patterns require more caution.