Woodchip Bedding as Enrichment for Captive Chimpanzees in an Outdoor Enclosure

Abstract

AbstractThe use of woodchips as bedding for 16 juvenile chimpanzees (Pan troglodytes) was evaluated for the effects on behaviour, health and husbandry practices. Woodchip bedding was placed in two outdoor play areas for five consecutive days. Behavioural data were recorded in the morning and afternoon of each day, and compared to pre- and post-test data. A total of 44 hours of observations, made up of 1 hour scan sample sessions, were completed for the study. Behaviours in the following categories were measured: abnormal, affinitive, aggressive, environmental manipulation, inactivity, locomotion, play, self manipulation and woodchip manipulation. The location of each animal was also recorded Analysis of the data indicated that the chimpanzees engaged in woodchip-related behaviours for an average of 20.52 per cent of the data points, and that they spent more time manipulating the substrate in the morning than in the afternoon. In addition, abnormal behaviour, environmental manipulation and affinitive behaviours were significantly lower during the woodchip condition than during pre-test and post-test conditions. The subjects spent the most time on the floor of the enclosure, and this measure did not differ between conditions. The woodchip bedding did not cause any known health problems for the chimpanzees. Although the daily addition and removal of woodchips took more time than did routine cleaning, it kept the play areas cleaner and drier. The evaluation of woodchip bedding as enrichment was favourable and indicated that bedding may be used regularly in the maintenance of captive chimpanzees.