Variables that influence the activity of captive orangutans

Abstract It is well known that the environment significantly influences the behavior of captive animals. However, the specific nature of the cues that promote speciestypical behavior patterns is not usually known. This study extends an earlier investigation by Wilson ( Zoo Biology 1: 201–209, 1982). The objective was to identify and quantify specific environmental components that influence activity levels in orangutans. Six enclosure variables were quantified, and activity levels measured, for 29 orangutans housed in nine zoological parks. Multiple regression analysis indicated that the combination of the number of animals, amount of usable surface area, number of movable objects, and enclosure volume was the best predictor of activity levels, accounting for 58% of the variance in activity levels. It was concluded that the provision of large enclosures, containing large numbers of movable objects and providing social opportunities, would promote higher levels of activity in captive orangutans. © 1992 Wiley‐Liss, Inc.