Recent estimate of Asian elephants in Borneo reveals a smaller population. Issue 2 (14th February 2022)
- Record Type:
- Journal Article
- Title:
- Recent estimate of Asian elephants in Borneo reveals a smaller population. Issue 2 (14th February 2022)
- Main Title:
- Recent estimate of Asian elephants in Borneo reveals a smaller population
- Authors:
- Cheah, Cheryl
Yoganand, K. - Abstract:
- Abstract : Asian elephants occurring in northern Borneo form a geographically isolated and genetically distinct population. Of this, the subpopulation of Central Sabah holds the greatest opportunity for long‐term survival, due to a relatively large population size and occurrence over a vast, contiguous and protected habitat. We surveyed this subpopulation in 2015 using advanced methods to obtain a population size estimate. We used the distance‐sampling framework and laid out transects following a stratified random design for counting elephant dung piles; measured dung decay following the 'retrospective' method; and used Bayesian analysis to estimate dung decay rate and dung pile density. Thus, we estimated a posterior mean dung decay rate of 212 days (95% BCI: 133–319), an overall elephant density of 0.07 per km 2 (95% BCI: 0.03–0.11) and a population size of 387 elephants (95% BCI: 169–621). These estimates were far lower than the population size of 1132 individuals and density of 1.18 per km 2 estimated in 2008. It is unlikely that there has been a steep population decline, as there were no drastic land‐use changes between 2008 and 2015, nor were there other identifiable causes for a population decline. Therefore, it appears that the methodological and analytical flaws in the previous estimate are the most plausible reason for this observed difference. Given that the new estimate suggests a much smaller population, it is prudent and precautionary to use the new estimate asAbstract : Asian elephants occurring in northern Borneo form a geographically isolated and genetically distinct population. Of this, the subpopulation of Central Sabah holds the greatest opportunity for long‐term survival, due to a relatively large population size and occurrence over a vast, contiguous and protected habitat. We surveyed this subpopulation in 2015 using advanced methods to obtain a population size estimate. We used the distance‐sampling framework and laid out transects following a stratified random design for counting elephant dung piles; measured dung decay following the 'retrospective' method; and used Bayesian analysis to estimate dung decay rate and dung pile density. Thus, we estimated a posterior mean dung decay rate of 212 days (95% BCI: 133–319), an overall elephant density of 0.07 per km 2 (95% BCI: 0.03–0.11) and a population size of 387 elephants (95% BCI: 169–621). These estimates were far lower than the population size of 1132 individuals and density of 1.18 per km 2 estimated in 2008. It is unlikely that there has been a steep population decline, as there were no drastic land‐use changes between 2008 and 2015, nor were there other identifiable causes for a population decline. Therefore, it appears that the methodological and analytical flaws in the previous estimate are the most plausible reason for this observed difference. Given that the new estimate suggests a much smaller population, it is prudent and precautionary to use the new estimate as the basis for all policy decisions and conservation actions for elephants in Sabah. Abstract : … (more)
- Is Part Of:
- Wildlife biology. Volume 2022:Issue 2(2022)
- Journal:
- Wildlife biology
- Issue:
- Volume 2022:Issue 2(2022)
- Issue Display:
- Volume 2022, Issue 2 (2022)
- Year:
- 2022
- Volume:
- 2022
- Issue:
- 2
- Issue Sort Value:
- 2022-2022-0002-0000
- Page Start:
- n/a
- Page End:
- n/a
- Publication Date:
- 2022-02-14
- Subjects:
- Asian elephant -- Borneo -- density estimation -- distance sampling -- dung count -- dung decay rate -- population size -- Sabah
Wildlife conservation
Wildlife management
Animal ecology
590 - Journal URLs:
- http://onlinelibrary.wiley.com/ ↗
https://onlinelibrary.wiley.com/journal/1903220X ↗ - DOI:
- 10.1002/wlb3.01024 ↗
- Languages:
- English
- ISSNs:
- 0909-6396
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
- Physical Locations:
- British Library DSC - BLDSS-3PM
British Library HMNTS - ELD Digital store - Ingest File:
- 23477.xml