Abstract # 75:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


SUBSTRATE USE AND SOCIOSPATIAL PATTERNS IN A ZOO-LIVING ORANGUTAN (PONGO PYGMAEUS) GROUP

E. L. Zucker and P. R. Hanna
Loyola University, Department of Psychology, New Orleans, LA 70118, USA
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Differential substrate use likely mediates proximity and interactions between individuals in primate groups. Three types of observational data, from a four-member orangutan group at the Audubon Zoo (New Orleans, LA; 11-year old male, 41-, 16-, and 8-year old females), were used to assess relationships between substrate use and sociospatial patterns: Inter-animal distances and degree of arboreality (A) and terrestriality (T) (both determined from 256 5-minute instantaneous samples), and time in proximity (within 5 meters of others; from focal animal samples). Overall, orangutans were arboreal in 31.8% of the samples; individual percentages varied between 6.0% and 43.7% arboreal. In this zoo habitat, dyadic proximity was possible whether individuals used the same substrate (AA or TT) or different substrates (AT). The closest dyads (based on 146 qualifying instantaneous samples) were using the same substrate in 66.4% of the samples [52.7% TT, 13.7% AA], while the furthest dyads were using the same substrate in 65.8% of the samples [61% TT, 7% AA]. Individually, the adult male was in proximity most with the 16-year old female, and they showed similar A-T percentages, as did the dyad comprised of the oldest adult female and the youngest female. These results illustrate that, while habitat design and quality can provide extensive opportunities for arboreal proximity and other interactions, individual differences are manifested in habitat use, even in a highly arboreal species.