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Providing evidence to improve practice

Individual study: Environmental enrichment for zoo bears

Published source details

Carlstead K., Seidensticker J. & Baldwin R. (1991) Environmental enrichment for zoo bears. Zoo Biology, 10, 3-16


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Carnivores: Hide food around enclosure Management of Captive Animals

A small before-and-after study in 1988 of a black bear Ursus americanus in a zoo in the USA found that when food was hidden around the enclosure (including inside objects) walking and stereotypical pacing behaviours decreased and exploring/foraging behaviours increased compared to when food was not hidden. Stereotypical pacing was lower when food was hidden around the enclosure (median 20 minutes/day) compared to being placed on the floor of the indoor area (median 125 minutes/day) as was walking whereas exploring/foraging was higher (mean values not reported). One black bear was fed once or twice daily before the study and during baseline data collection (8 days). During the first condition (6 days), the bear was still given the morning feed as well as a feeder tree containing snacks. The feeder tree released snacks at scheduled times of day, releasing food at six different locations. The second condition (8 days) included hiding all food apart from the meat around the enclosure, under rocks, in logs and in Boomer balls. Video recordings were taken for 12 hours starting 06:00 each and continuous focal sampling method was used.

Carnivores: Present food inside objects (e.g. Boomer balls) Management of Captive Animals

A small before-and-after study in 1988 of a sloth bear Melursus ursinus in a zoo in the USA found that the first and second presentation of honey-filled logs decreased walking/pacing and explore/foraging behaviours compared to before enrichment. Both walking/pacing (first presentation: 10 min/day); second presentation: 71 min/day) and explore/foraging (first presentation: 13 min/day; second presentation: 35 min/day) behaviours decreased when presented with honey-filled logs (walk/pace: 124 min/; explore/forage: 60 min/day).  Explore/forage behaviour was lower on the third presentation compared to before enrichment, however walk/pacing was not significantly lower. One sloth bear was presented with a honey-filled log after six days of baseline observations. The log was presented for five days and was refilled twice. The log was then removed for two days and re-presented for a further four days. Post test data was collected for five days and lastly the log was presented for five continuous days. A camera recorded six hours daily 09:30 h to 15:30 h and continuous focal sampling was performed.