Abstract # 4392 Poster # 50:

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


DEFINING FEMALE BORNEAN ORANGUTAN (PONGO PYGMAEUS WURMBII) RANGING BEHAVIOR USING GEOSPATIAL ANALYSIS: HOME RANGE CHARACTERISTICS, OVERLAP, AND RANGE DURING LOW-FRUIT AVAILABILITY

A. DiGiorgio and C. Knott
Boston University, Dept of Biological Anthropology, 232 Bay State Ave, Boston, MA 02215, USA
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     Female orangutan ranging behavior is highly variable. Estimates of home-range yield figures from 40 to >850ha, and differ between and within habitat types and research sites. Further, though orangutans are semi-solitary animals, adult female orangutans have considerable range overlap. We examine whether, within Gunung Palung National Park (West Kalimantan, Indonesia), the range of each adult female is clustered, dispersed, or random, and describe total area, overlap, and unique components of these ranges. Additionally, we depict orangutan ranging behavior during low fruit availability (LFA, < 10% stems fruiting). With highly overlapping ranges, do females converge into a few common areas during LFA or do they separate into different areas? Home ranges are mapped in ArcGIS using focal follow data for eight adult female orangutans (PONGO PYGMAEUS WURMBII) collected on encounter from November 2008 through August 2011. We find preliminary evidence for clustered female home-ranges (point data, Moran’s Index 0.285, p < 0.01) with substantial overlap between animals. Home-range areas vary from 78 to 452ha. For each animal’s total range, an average of only 13.5% was non-overlapping (unique). During LFA, all followed orangutans (n = 5) converged to a central area of range overlap and only one orangutan utilized her unique area. These findings are depicted graphically to elucidate range characteristics and habitat-type use.