Quick Search:

uzh logo
Browse by:

Zurich Open Repository and Archive

Maintenance: Tuesday, July the 26th 2016, 07:00-10:00

ZORA's new graphical user interface will be relaunched (For further infos watch out slideshow ZORA: Neues Look & Feel). There will be short interrupts on ZORA Service between 07:00am and 10:00 am. Please be patient.

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-3914

Wich, S A; Meijaard, E; Marshall, A J; Husson, S; Ancrenaz, M; Lacy, R C; van Schaik, C P; Sugardjito, J; Simorangkir, T; Traylor-Holzer, K; Doughty, M; Supriatna, J; Dennis, R; Gumal, M; Knott, C D; Singleton, I (2008). Distribution and conservation status of the orang-utan (Pongo spp.) on Borneo and Sumatra: how many remain? Oryx, 42(3):329-339.

View at publisher


In recognition of the fact that orang-utans (Pongo spp.) are severely threatened, a meeting of orang-utan experts and conservationists, representatives of national and regional governmental and non-governmental organizations, and other stakeholders, was convened in Jakarta, Indonesia, in January 2004. Prior to this meeting we surveyed all large areas for which orang-utan population status was unknown. Compilation of all survey data produced a comprehensive picture of orang-utan distribution on both Borneo and Sumatra. These results indicate that in 2004 there were c. 6,500 P. abelii remaining on Sumatra and at least 54,000 P. pygmaeus on Borneo. Extrapolating to 2008 on the basis of forest loss on both islands suggests the estimate for Borneo could be 10% too high but that for Sumatra is probably still relatively accurate because forest loss in orang-utan habitat has been low during the conflict in Aceh, where most P. abelii occur. When those population sizes are compared to known historical sizes it is clear that the Sumatran orang-utan is in rapid decline, and unless extraordinary efforts are made soon, it could become the first great ape species to go extinct. In contrast, our results indicate there are more and larger populations of Bornean orang-utans than previously known. Although these revised estimates for Borneo are encouraging, forest loss and associated loss of orang-utans are occurring at an alarming rate, and suggest that recent reductions of Bornean orang-utan populations have been far more severe than previously supposed. Nevertheless, although orang-utans on both islands are under threat, we highlight some reasons for cautious optimism for their long-term conservation.


76 citations in Web of Science®
82 citations in Scopus®
Google Scholar™



451 downloads since deposited on 23 Sep 2008
67 downloads since 12 months

Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, further contribution
Communities & Collections:07 Faculty of Science > Anthropological Institute and Museum
Dewey Decimal Classification:300 Social sciences, sociology & anthropology
Deposited On:23 Sep 2008 14:38
Last Modified:05 Apr 2016 12:28
Publisher:Cambridge University Press
Publisher DOI:10.1017/S003060530800197X

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page