Higher mortality rates for large and medium-sized mammals on plantation roads compared to highways in Peninsular Malaysia

The fragmentation of forests by agricultural expansion, urbanisation and
road networks is a global phenomenon. In Southeast Asia, wildlife
populations are being isolated into pockets of natural habitat surrounded
by road networks and monoculture plantations. Mortality by
wildlife-vehicle collisions (WVCs) is causing a decline in many species of
conservation priority in human-modified landscapes. This study is the
first in Malaysia to investigate factors affecting the occurrence of WVCs.
We assessed roadkill data gathered by the Department of Wildlife and
National Parks on small, medium and large mammals in Peninsular Malaysia.
We examined the relationship between wildlife road accidents and
environmental factors. We found a total of 605 roadkills, involving 21
species. Roadkill records included three species classified as endangered.
Road type, year, and distance from continuous and fragmented forests were
significant for determining mammal mortality. Unexpectedly, the majority
of road mortality occurred on oil palm plantation roads compared to
highways. Mortality of small and medium mammals was greater at locations
further away from continuous forest than those closer to forests.
Segmentation of continuous forest by roads should be avoided wherever
possible, and wildlife corridors should be put in place to reduce the
threat of roads on crossing wildlife.