Preferential Space Use Exhibited by Individual Orangutans in an Innovative Enclosure at Auckland Zoo.

To meet the needs of socially complex primates, modern zoo enclosures are designed to include structural, sensory, food-based, and tactile enrichment, as well as opportunities to express the behavioral preferences of zoo-housed individuals. The welfare of captive primates is commonly measured by the expression of species-typical behaviors; and more recently by analyzing space use. Here, we present data from a study on preferential space use for three adult orangutans housed at Auckland Zoo. One of the zoo's main goals, with the recent introduction of an overhead line pathway, was to encourage arboreal movement and to increase time spent off the ground. Findings from this study show significant departure from expected values for use of both location and height. Most notably, all individuals used the overhead pathway within values expected by chance, but there was significant variation in location use within the enclosure. Residuals indicate that each orangutan has personal preference for different areas and height ranges of their enclosure, which is supported by behavioral observations. Enclosure use is heavily influenced by individual preferences, physical capabilities, and husbandry practices.