Effects of food manipulation on home range size in Tamias striatus.

Abstract

The home range of an individual represents the spatial component of its overall fitness (Bowers, 1989). As the distribution of resources such as food changes, an animal must adjust its home range in order to maximize its fitness. Home range sizes of Tamias striatus (eastern chipmunks) were measured before and during a feeding manipulation. We hypothesized that home ranges would expand in response to the introduction of a new and rich food source outside of their original home ranges. Home ranges of chipmunks within 63 meters of the feeding site shifted and increased in size by 876 m2 on average, while the home range of a chipmunk 143 meters from the feeding site did not change. Burrow locations remained unchanged throughout the study, while overlap among home ranges of different chipmunks increased greatly. Conspecific aggression increased sharply.