PARENT SESSION
Oral Session #101: Plant-Animal Interactions.
Presiding: S. Faeth
Friday, August 9. 9:00 AM to 12:00 PM. Coconino Meeting Room, TCC.

Fox squirrels as future traders: the value of cacheable and non-cacheable food.

Van der Merwe, Marius^*,1, Brown, Joel¹, Kotler, Burt², ¹ University of Illinois at Chicago, Chicago, IL² Ben-Gurion University, Beer Sheva, Israel

ABSTRACT- When an animal encounters a cacheable food item, there are two potential values associated with it. The animal may choose to eat the food immediately, in which case it has a present value, or the animal may choose to cache it for later, in which case it has a future value. Hence, cacheable foods create a personal futures market and gives the caching animal more behavioral options than non-cacheable foods. All else being equal, a cacheable food should be valued more than a non-cacheable food. We tested this prediction with fox squirrels (Sciurus niger) and cacheable (unshelled) and non-cacheable (shelled) hazelnuts. By measuring GUDs of buried nuts in artificial food patches, we determined that squirrels valued cacheable nuts more than non-cacheable nuts. Our results show that 37% of the value of cacheable hazelnuts is future value. Though other variables like site, day and season have significant effects on GUDs, all are dwarfed by the effect of food cacheability.

KEY WORDS: fox squirrel, Sciurus niger, caching behavior, future food value