Use of temporary and semipermanent enrichment objects by five chimpanzees.

At the Chimpanzee and Human Communication Institute, caregivers provide the 5 chimpanzees who reside there with many different forms of social, food, habitat, and object enrichment. In this study, we examined the chimpanzees' use of both semipermanent and temporary objects. Semipermanent objects included cargo nets, climbing structures, a treat mound, and other objects that were present at the chimpanzees' enclosure throughout the duration of this study. Each day, 50 temporary objects were placed in the chimpanzees' outdoor enclosure or indoor exercise rooms. Frequency of use was examined in 2 conditions: rotated and same. In the rotated condition, temporary objects were replaced with different temporary objects after 3 hr. In the same condition, temporary objects were presented for the entire day. Focal and scan sampling were used to record the chimpanzees' use of enrichment objects. Observers collected focal sample data to record the chimpanzees' initial reaction to objects when entering the indoor exercise rooms, outdoor enclosures, or both at 9:00 a.m. and 1.00 p.m. A total of 35 hr of focal data and 156 hr of scan data were collected over an 8-week period. Temporary object rotation increased the overall frequency of temporary object use both in the initial 15 min of focal sample data and during the following 6 hr of scan sample data for 4 of the chimpanzees. All of these chimpanzees used both semipermanent and temporary objects throughout the day. Each chimpanzee's pattern of use was unique. The results of this study emphasize the importance of temporary object rotation and presentation of both temporary and semipermanent objects to captive chimpanzee environments.