posted on December 30, 2009 21:16
Efforts to protect and monitor elephant populations in the Seima Protection Forest (SPF), as in many parts of their range, had for a long time been hampered by a lack of information on population levels and trends, as well as a paucity of data concerning elements such as movement patterns and seasonal migrations. With this in mind, the SPF monitoring program was extended in 2006 to include a fecal DNA based survey that was designed to provide the first reliable population estimate for elephants in the area.
Elephants currently live at very low densities and are dispersed across large areas. Conventional methods such as dung-count based surveys are not appropriate under such circumstances, given the difficulties in (1) estimating elephant dung-pile abundance with tolerable precision when elephant density is low, (2) finding adequate numbers of dung-piles for the necessary pre-survey decay rate monitoring experiments and 3) estimating elephant defecation rates when elephants occur at such low densities.
Instead the use of fecal DNA based population estimates based on capture–recapture models was recommended. These molecular genetic approaches to estimating mammal population size are increasingly used for cryptic species and/or those living at low densities, and are particularly helpful in overcoming the difficulties of dung-count based surveys.
A total of 255 samples were collected during the course of the survey and the survey revealed important new information concerning the size and structure of the SPF elephant population. The number of elephants in the SPF was estimated at 116 individuals. As well as being larger than expected, the SPF elephant population was shown to be part of a metapopulation, with individuals interbreeding with other local populations. This suggests that proper protection could also lead to a recovery of elephant populations in the area, as SPF and the wider protected area complex in Southern Mondulkiri have extensive areas of elephant habitat remaining.