Zoo Biology 10:3-16 (1991) RESEARCH ARTICLES Environmental Enrichment for Zoo Bears

The high incidence of Stereotypie behaviors in zoo bears (van Keulen-Kromhout: International Zoo Yearbook 18:177-186, 1978) suggests that the environment of these animals lacks essential stimuli for guiding normal behavior. Three experi-ments investigated ways in which bear husbandry procedures can be altered to promote normal behavior. In experiments 1 and 2, honey-filled logs were given to a sloth (Melursus ursinas), American black (Ursus americanus), and brown bear (Ursus arctos) to determine 1) the role of food in stimulating investigatory behavior, 2) the rate of habituation to manipulable objects introduced into the exhibit, and 3) effects on locomotory behaviors. Results show specific and gen-eral habituation to the introduced objects that can be counteracted by refilling the logs with honey and by providing multiple logs in the exhibit. Investigatory activity directed toward honey-logs replaces pacing and walking in the sloth bear and is most effective in doing so when the log is novel. Experiment 3 examined the behavioral effects of feeding an American black bear in three different ways: 1) once daily in the den, 2) once daily with supplemental food from a mechanical feeder, and 3) once daily with food hidden in the exhibit in manipulatable objects. The latter method reduced Stereotypie pacing from a median of 150 min/day to 20 min/day; the mechanical feeder method had no such effect. The results of a survey of 67 zoos concerning the diet and manner of feeding these three species of bears, as well as Asian black bears (Ursus thibetanus) are presented. Results are dis-cussed with respect to the ways in which husbandry procedures can be improved to stimulate functional foraging and feeding behavior in confined bears. Key words: object manipulation, feeding, foraging, husbandry procedures, cage fur-nishings, Stereotypie behavio