An investigation into keeper opinions of great ape diets and abnormal behaviour

Rebecca Hammerton, Kerry Hunt, Lisa Riley

Research output: Contribution to journalArticlepeer-review

Abstract

Zoos are evidencing a shift in great ape diets to cultivated fruit-free to achieve a more wild-type nutritional composition (lower sugar, higher fibre). This study aimed to ascertain great ape keeper knowledge and opinions on the removal of cultivated fruit from great ape diets, to investigate feeding regimes currently in use and to understand the prevalence and frequency of abnormal behaviour and health conditions within captive great apes that may be related to diet. Keepers from 11 collections in the British Isles participated by completing a standardised questionnaire; this provided information on 20 great ape groups. Keepers report, two thirds of great ape groups were fed cultivated fruit, but zoos intended that half of these go cultivated fruit-free in future. All groups were fed multiple times a day using multiple feeding strategies. Significantly more groups were fed using eight feeding strategies, very few groups were fed using less than seven feeding strategies (P=0.001). Most keepers (whether their apes were fed a cultivated fruit-free diet or were fed cultivated fruit) believed their apes’ diets were not comparable to the wild. However, all keepers, irrespective of diet type, agreed or agreed strongly that their great apes were in good health and were motivated by their diet. Fifteen abnormal behaviours were noted by keepers across all groups; regurgitation and reingestion, regurgitation, and coprophagy were reported significantly more than other abnormal behaviours (P=0.045) but no significant differences (in prevalence or frequency) were reported for these behaviours between cultivated fruit free and cultivated fruit-eating groups. Keeper-reported prevalence of spinning (P=0.001) and self-patting (P=0.001) were significantly higher in groups fed a cultivated fruit-free diet compared to those fed cultivated fruit; however, prevalence of hyper-aggression was significantly higher in groups fed cultivated fruit (P=0.001). Keepers reported abnormal behaviours were significantly more prevalent in gorillas given the average performance across all three species (P<0.001) while chimpanzees showed a tendency to perform abnormal behaviours more frequently. Further research into keeper opinions on primate diets, nutritional analysis between diets (cultivated fruit-free versus cultivated fruit-containing), and experimental data pre- and post-removal of cultivated fruit from primate diets is required.
Original languageEnglish
Pages (from-to)170-178
JournalJournal of Zoo and Aquarium Research
Volume7
Issue number4
DOIs
Publication statusPublished - 31 Oct 2019

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