UC Davis

Anticipatory behavior (AB) has been reported to be a potential indicator of an animal’s subjective affective state and is thought to be modulated by the animal’s reward sensitivity and motivation to acquire a resource. In considering the role of evolutionary pressures shaping seasonal behavior (i.e., hyperphagia and torpor) and the significance of resource driven anticipatory behavior in many of the Ursus genus living in North America, we chose to investigate trends of AB: A) across the day in a baseline year in order to validate our focal behaviors as AB by definition and B) in response to allotment of treatment types varying in timing and number of daily food-related reward opportunities via use of a scatter-feeder across an experimental year in two resident grizzly bears at the San Francisco Zoo. Upon validating our behavior according to the definition (i.e., increase before predictable rewarding event and near-cessation post event), post-hoc analysis revealed a general seasonal effect on both of our dependent AB measures (total AB duration and average AB bout length, in seconds per observation session) in both bears and research years. Except for differences seen in total AB duration performed in the winter between baseline and experimental years, we found no other overall significant effects of scatter feeding treatment on total AB duration or AB bout length. Specific treatment type effects appeared to be highly influenced by season which speaks to the engrained motivation to participate in temporally significant behavioral patterns. In summary, our findings reveal that AB may serve as a potential indicator of motivation to acquire resources, but interpretation of AB patterns and implementation of enrichment must be taken with caution and with species-specific natural history in mind.