The distribution of medium to large mammals in Samunsam Wildlife Sanctuary, Sarawak in relation to the newly constructed Pan-Borneo Highway

Abstract

Protected Areas in Borneo retain some of the best examples of biodiversity and are the last refuge for wildlife conservation in tropical rainforests. Therefore, understanding the species richness and composition in increasingly fragmented Protected Areas are crucial in wildlife monitoring and management. The recent road construction splitting the oldest wildlife sanctuary in Sarawak has warranted further investigation on the species distribution. Camera trap survey in Samunsam Wildlife Sanctuary (SWS), western Borneo resulted in 20 medium- to large-bodied mammals from 775 independent photos with 2001 camera trap nights from surveys done in 2013–2014 and 2019. SWS records the Endangered Nasalis larvatus and Cynogale bennettii in the current survey. Under the Sarawak Wild Life Protection Ordinance 1998, Nasalis larvatus was the only recorded species considered to be Totally Protected while 12 other species are listed as Protected and the remaining species were not listed. The most frequently recorded species were Tragulus spp. (n = 147 in 2013–2014 and n = 166 in 2019) followed by Macaca fascicularis in 2013–2014 with n = 109, and Sus barbatus (n = 93 in 2019). A similar species richness (n = 13) was recorded both near ( 1000 m). However, the mean species richness was higher further away from the road (> 1000 m). Herpestes brachyurus, Hemigalus derbyanus, and Echinosorex gymnura were only recorded near the road while Cynogale bennettii, Hystrix brachyura and Nasalis larvatus were only recorded further away from the road. Through the bipartite network analysis, the majority of the medium- to large-bodied mammals are distributed in the mixed dipterocarp forests. Species that have habitats within proximity to the road have a higher risk of mortality due to roadkill and other anthropogenic pressure. Encroachment is an issue in Samunsam Wildlife Sanctuary and calls for immediate action; stricter enforcement, regular wide-coverage patrols along the river, and on the road to prevent illegal logging, commercial planting, and hunting.

Keywords

• camera traps
• enforcement
• fragmentation
• protected area
• road
• tropical rainforests