Habitat fragmentation and genetic diversity in natural populations of the elephant – Importance of connectivity between spatially distinct populations- A case study of Bornean elephant population in Sabah

Habitat fragmentation and genetic diversity in natural populations of the Bornean elephant: Implications for conservation

Benoit Goossensa,Reeta Sharmae, Nurzhafarina Othmana, Célia Kun-Rodriguese, Rosdi Sakonga, Marc Ancrenazf, Laurentius N. Ambuc, Nathaniel K. Jueg, Rachel J. O'Neillg, Michael W. Bruforda and  Lounès Chikhie.

Biological Conservation,Volume 196, April 2016, Pages 80–92

The Bornean elephant population in Sabah, with only 2000 individuals, is currently found in limited number of forest reserves. Fragmentation of habitat and isolation of the existing herds are posing serious threat to elephants. To give a boost to the conservation initiatives the researchers assessed the genetic diversity and population structure of Bornean elephants using mitochondrial DNA, microsatellites and single nucleotide polymorphisms. The results reinforced a previously reported lack of mitochondrial control region diversity, characterized by a single widespread haplotype. Microsatellite analysis showed that Bornean elephants from the Lower Kinabatangan and North Kinabatangan ranges are differentiated and perhaps isolated from the main elephant populations located in the Central Forest and Tabin Wildlife Reserve. 

The results of the study amply demonstrated that (i) Bornean elephants probably derive from a very small female population, (ii) they rarely disperse across current human-dominated landscapes that separate forest fragments, and (iii) forest fragments are predominantly comprised of populations that are already undergoing genetic drift. The researchers emphasize that to maintain the current levels of genetic diversity in fragmented habitats, conservation of the Bornean elephants should aim at securing connectivity between spatially distinct populations.