Survival strategies of the sun bear (Helarctos malayanus) in the lower Kinabatangan, Sabah, Malaysian Borneo

Abstract

The Southeast Asian island of Borneo is an important stronghold for the sun bear (Helarctos malayanus). However, largely due to the expansion of oil palm (Elaeis guineensis) plantations, prime sun bear habitat in Borneo has either been lost or is severely fragmented. The lower Kinabatangan floodplain in Sabah, Malaysian Borneo is an example of a particularly fragmented landscape, with small forest fragments amid vast areas of oil palm. Our research aimed to understand how sun bears are able to survive in this seemingly poor habitat. First, we used camera traps and sign surveys to examine trends in habitat use and activity patterns of bears within the remaining forested areas. Next, we interviewed oil palm plantation workers and farmers to identify if sun bears and other threatened wildlife fed on oil palm fruits, and if conflicts with people resulted because of this. Our results indicated that, compared to primates, wild pigs, and elephants, sun bears were able to feed on oil palm fruits without causing much damage to the crop, and, more importantly, without being detected. Sun bears did use narrow riparian corridors to move between larger forest fragments, but did not spend much time feeding or resting within these corridors. Larger forest fragments served as a better buffer from human activities, and were more intensively used by bears. On certain habitat features, such as forest trails, sun bears were more nocturnal and reduced using these features in proximity to people. This research highlights the importance of relatively small forest areas (~ 20 km2) for sun bears in a landscape dominated by agriculture. Sun bears have proved to be remarkably resilient in the face of dramatic habitat and landscape changes.