Marian Hamilton

Grant Type

Dissertation Fieldwork Grant

Institutional Affiliation

New Mexico, Albuquerque, U. of

Grant number

Gr. 9309

Approve Date

April 21, 2016

Project Title

Hamilton, Marian I., U. of New Mexico, Albuquerque, NM - To aid research on 'Tracking Dispersal and Home Range Size with Environmental and Faunal Strontium Isotopes,' supervised by Sherry Nelson

Preliminary abstract: While the fossil record captures many crucial details of our evolutionary past, it does not preserve social behavior. Certain aspects of spatial landscape use, such as dispersal and home range size, have major consequences on social organization. An accurate reconstruction of landscape use by fossil hominins would therefore be an empirical proxy for otherwise-elusive social behaviors. Strontium isotope ratios are frequently used to track faunal and human movement because these ratios vary based on underlying bedrock composition and are mirrored in local plants. Animals incorporate plant ratios into their tissues as they eat. Isotopic ratios in faunal tissues thus vary based on the bedrock(s) over which the animal moved during the tissue’s formation. However, the link between social organization and strontium isotopes has not yet been confirmed in a modern primate ecosystem. This study will use environmental and faunal strontium isotope data from Kibale National Park, a rainforest habitat, and Toro-Semliki Wildlife Refuge, a gallery forest/ savanna habitat, both of which are home to numerous chimpanzees and other primates. First, this study will quantify the isotopic variation within each ecosystem by sampling plant and water resources. Next, isotopic ratios from chimpanzees and other resident fauna will be overlaid on this isotopic ‘map’ to see how accurately the isotopic data predicts known patterns of philopatry, ranging, and dispersal behavior. It will then be possible to use these results to inform future methodological study designs and data analyses for research focused on fossil assemblages. This study represents the first strontium isotope study in a modern primate habitat. By testing for correlations between faunal strontium isotope ratios, their patterns of movement, and their social behaviors, this study will provide the first extant model for hominin socio-behavioral reconstructions.