Abstract # 145:

Scheduled for Saturday, June 21, 2008 10:45 AM-10:55 AM: Session 16 (Meeting Room 1GHI) Oral Presentation

Proximities and Interindividual Distances Following Male Replacement in a Zoo-living Group of Orangutans (Pongo pygmaeus)

E. L. Zucker
Loyola University, Department of Psychology, New Orleans, LA 70118, USA
     A 10-year-old male (BE) was introduced to the orangutan group at the Audubon Zoo in December 2002, after the long-time resident male’s death. BE’s sociospatial relationships with 3 females (aged 40, 15, and 7) were studied (April-May 2003; 50 hours of focal sampling of BE), and patterns compared to those of the previous male (studied periodically since 1984). Females’ ages (and reproductive values) were predicted to mediate the male’s proximities and interindividual distances. BE was between 1 and 5 meters of others for 14.8% of the observation time (most near the intermediate-aged female, least near the oldest female) and within 1 meter of others for 14.2% of the time (most near the youngest female, least near the oldest female). Mean interindividual distances, calculated from 572 instantaneous samples done at 5-minute intervals, indicated BE typically was closest to the oldest female (5.2 m) and furthest from the youngest female (5.7 m). Mean distances between BE and both the oldest female and the intermediate-aged female were within the ranges observed for these females and the former male during past years (1984, 1994, and 1995 for the oldest female, 1994 and 1995 for the intermediate-aged female). Observed sociospatial patterns were not consistently related to age (nor reproductive value), and the introduction of a new male did not dramatically alter intra-group spatial relationships, indicative of consistency and/or adaptability.