Load Size Variation in the Eastern Chipmunk,Tamias striatus: The Importance of Distance from Burrow and Canopy Cover

We examined the degree to which chipmunks foraging from dishes containing sunflower seeds varied cheek pouch load size according to both travel time (distance from burrows) and predation hazard (canopy cover). Results showed that larger loads were taken under cover at some distance from burrows than were taken from closer or more open sites. Distance effects appeared to reflect the influence of traveling times on quitting harvest rates as predicted by central place foraging models. Quitting harvest rates also appeared to be higher under low than under dense canopy cover; this trend was most pronounced at some distance from burrows suggesting that foraging decisions were made relative to both energetics and predator avoidance. Chipmunks appeared to employ a patch exploitation strategy that minimized the hazard:gain ratio.