1 VEGETATION CORRELATES OF GIBBON DENSITY IN THE SEBANGAU NATIONAL PARK, CENTRAL KALIMANTAN, INDONESIA

Understanding the links between animal populations and the characteristics of their habitat is essential for their conservation. Following recent re-assessments of the conservation status of the Bornean agile gibbon (Hylobates albibarbis), the need to conserve the peat-swamp forests of Kalimantan, one of its main habitats, is more pressing than ever. Little information is available on gibbons in peat-swamp forest. The aim of this study was to investigate the relationship between vegetation characteristics and gibbon density in a newly protected, secondary peat-swamp forest in the Sebangau National Park. The study was conducted from 1st May to 28th July 2008, using auditory sampling methods and speed plotting. Gibbon densities and vegetation characteristics were recorded at 13 sites within the Natural Laboratory for the Study of Peat-swamp Forest. Gibbon densities were calculated after the number of groups in each area was determined by plotting all recorded calls on a map. Gibbon densities ranged from 1.39 to 3.92 groups/km, and were found to be correlated with canopy cover at 20m, median tree height, density and biomass of large trees and food availability. These results highlight the importance of large, tall trees and good canopy cover for the gibbon population in the Sebangau forest; they indicate that conservation efforts should be directed to the preservation of those large trees and the prevention of selective logging, which targets them. It is hoped that the results of this survey will contribute to the preservation of both Indonesia’s peat-swamp forests and the gibbons that inhabit them.