Abstract # 13122 Event # 173:

Scheduled for Saturday, August 11, 2018 10:45 AM-11:00 AM: (Chula Vista ) Oral Presentation


C. L. Egelkamp1, S. L. Jacobson1, K. A. Cronin1, M. Fidino2, S. R. Ross1 and L. M. Hopper1
1Lester E. Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo, Chicago, IL 60614, USA, 2Urban Wildlife Institute, Lincoln Park Zoo, Chicago, IL 60614, USA
     As understanding animals’ food preferences benefits research and husbandry protocols, we evaluated two preference-testing methods with three primate species (Gorilla gorilla, Pan troglodytes, Macaca fuscata) (N=4 of each species). First, following a pairwise forced-choice preference paradigm, we showed subjects pairs of photographs of food items on a touchscreen. Subjects were tested with four foods in every possible pairing, with 90 trials per pairing, and rewarded with whichever food they selected. We used the R ‘prefmod’ package to calculate ‘worth’ values reflecting the subjects’ relative preferences. All four macaques preferred the foods in the same order and each food was significantly preferred over the next (p<0.01 for all comparisons). Six of the eight apes displayed significant preferences among the foods and the order and relative strength of their preferences varied. Second, the gorillas were tested on a paradigm in which they had to select a food image on a touchscreen n times to receive that food, where the cost, n, increased over sessions, effectively testing the ‘price’ subjects would ‘pay’ for the four foods. Currently, one gorilla has completed these trials. The demand curves generated from this paradigm indicated his highest-valued food was the same as his most-preferred food identified with the first paradigm. These methods allowed us to examine individual subjects’ relative preferences and valuations of the food items, not simply ranking order.