Recent estimate of Asian elephants in Borneo reveals a smaller population

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 km2 (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 km2
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.