Document Type

Thesis

Date of Degree Completion

Fall 2024

Degree Name

Master of Science (MS)

Department

Primate Behavior

Committee Chair

Nicole A. Jastremski

Second Committee Member

April K. Binder

Third Committee Member

Joshua Buchanan

Abstract

Great ape skeletal remains are scarce and their use in biological profile estimations has been limited. Skeletal remains analysis provides key demographic information and ecological context to the individual. Chimpanzees (Pan troglodytes) share skeletal morphological characteristics with humans, and this study seeks to understand if two noninvasive methods using the auricular surface of the ilium to age human skeletal remains could be applied to chimpanzees. The sample consisted of n = 8 individual left auricular surfaces from known age groups of both sexes. Firstly, the Buckberry and Chamberlain Method assigns numerical values to five different traits on the auricular surface: transverse organization, surface texture, microporosity, macroporosity, and apical changes. Secondly, the Lovejoy Method utilizes a broader application, viewing the whole surface rather than by feature, then assigning a phase depending on the presentation of features and surface organization. Assessment for both techniques was done for each ilium. Once completed, the Buckberry and Chamberlain Method, the total score for each ilium was determined, then it was matched with an age chart. This age given by the Adapted Buckberry and Chamberlain Method age chart was then compared to the actual known age of the individual. A linear regression analysis was conducted and macroporosity was found to be insignificant with a p-value of 0.4. Therefore, another linear regression was run with all traits excluding macroporosity. The second regression found an overall positive result with a p-value of 0.082. The Lovejoy Method, once the ilia received a phase, the age chart was assessed to see if the results of the Lovejoy Method assigned phase matched the known age of the individual. Both Lovejoy and Buckberry and Chamberlain Methods were able to correctly age 7 out of 8 individuals. This first study shows promising results using Adapted Buckberry and Chamberlain and Lovejoy Methods, for aging poached chimpanzees in the wild or for providing age estimations for chimpanzees in skeletal collections. I recommend that future studies look at differences between wild vs captive chimpanzees, increase sample sizes, and species and subspecies specific populations.

Download

Share

COinS