Date of Award


Document Type

Restricted Thesis

Terms of Use

© 2009 Helen Chmura. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts


Biology Department

First Advisor

Sara Hiebert Burch


Prior research indicates that environmental factors such as group size and habitat exposure affect vigilance behavior. However, little research has examined whether an animals' internal state affects its vigilance behavior. This study examined whether internal factors such as body condition, parasite infection, stress, and immune investment explain variation in yellow-bellied marmot (Marmota flaviventris) vigilance. We trapped adult and yearling marmots at Rocky Mountain Biological Laboratory (RMBL), Gunnison County, Colorado, USA during spring and summer months from 2003 to 2008 and sampled blood and fecal parasites. We observed the behavior of foraging marmots during 2 minute foraging focal samples. General linear models including internal and external state factors were fitted to marmot vigilance, foraging, and locomotor behaviors quantified in three ways. Results indicate that while internal factors do not significantly explain variation in marmot vigilance, these factors do explain variation in foraging and locomotor behaviors. While environmental factors consistently explained more variation in behavior than internal factors, results from this study suggest that internal factors play a significant role in determining behavior. However, each model left the majority of behavioral variation unexplained, indicating that many factors influencing behavior, especially vigilance behavior, remain unidentified.