Publication: Estimation of density of gibbon groups by use of loud songs
1
Issued Date
1993-01-01
Resource Type
ISSN
10982345
02752565
02752565
Other identifier(s)
2-s2.0-84996066989
Rights
Mahidol University
Rights Holder(s)
SCOPUS
Bibliographic Citation
American Journal of Primatology. Vol.29, No.2 (1993), 93-108
Suggested Citation
Warren Y. Brockelman, Sompoad Srikosamatara Estimation of density of gibbon groups by use of loud songs. American Journal of Primatology. Vol.29, No.2 (1993), 93-108. doi:10.1002/ajp.1350290203 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/22517
Research Projects
Organizational Units
Authors
Journal Issue
Thesis
Title
Estimation of density of gibbon groups by use of loud songs
Author(s)
Other Contributor(s)
Abstract
The density of gibbon populations may be estimated by listening for the loud duetted songs of monogamous territorial groups. This method requires a correction factor which must be estimated from the frequency of singing of an adequate number of known study groups. The correction factor and its error were estimated for pileated gibbons (Hylobates pileatus) in Khao Soi Dao Wildlife Sanctuary in southeastern Thailand. Among 30 groups studied, 47% sang per day, on average, but the variation between days and the variation in singing frequency between groups were large. Weather conditions, especially windiness, explained some variation in singing. During an area‐wide survey of groups in the sanctuary, unexplained variation in singing from day to day accounted for approximately half of the sample error of group density estimated from 1‐day listening samples. Error due to day‐to‐day variability can be reduced by listening for more than one day at each site. Correction factors based on the cumulative proportion of groups heard during longer (2–5‐day) sample periods of listening were closer to 1.0, therefore leaving less room for error and bias of the correction factor. © 1993 Wiley‐Liss, Inc. Copyright © 1993 Wiley‐Liss, Inc., A Wiley Company