Abstract # 41:

Scheduled for Thursday, June 21, 2012 07:00 PM-09:00 PM: Session 9 (Gardenia) Poster Presentation


E. Renner
The George Washington University, Hominid Paleobiology Doctoral Program, Center for the Advanced Study of Hominid Paleobiology, 2110 G Street, NW, Washington, DC 20052, USA
     In order to compare and contrast the use of enclosure space by captive gorillas and orangutans in the time just prior to night nesting, gorillas (Gorilla gorilla; N = 6) and orangutans (Pongo pygmaeus and Pongo pygmaeus × Pongo abelii hybrids; N = 6) at the National Zoo in Washington, DC, were observed in the late afternoons. The position, behavior, and location of individuals were recorded at 2-minute intervals during 1-hour group scans (modeled on methods described in Lukas et al., Int. J. Primatol., 2003). Because orangutans are arboreal, it was hypothesized that they would spend more time on elevated portions of their enclosures than floor-level areas. However, orangutans occupied an elevated substrate (e.g., hammock, artificial tree, or other elevated feature of the enclosure) on only 22.8% of the scans in which they were visible and a floor location on 77.2% of scans. Results for gorillas (not including the infant) were similar; they occupied an elevated substrate on 28% of scans and a floor location on 72% of scans. Possible reasons for the low percentage of time the apes spent in elevated areas may be related to exhibit design or hay placement in the enclosures. These results are relevant to zookeepers and exhibit designers who wish to encourage natural arboreal behaviors in the apes under their care.