Feeding Ecology of Mentawai langur (Presbytis potenziani) in Siberut, Mentawai Islands
Keywords:
feeding ecology, activity budget, diet, Presbytis potenziani, Mentawai islandsAbstract
Mentawai langur, Presbytis potenziani are endemic to the Mentawai Islands. The species is categorized as an endangered primate. Loss of suitable forest habitat, t hrough commercial logging and conversion of land to agriculture, and traditional hunting system are the main factor threatening populations of the species in all islands of Mentawai. Despite the urgent need for scientifically based conservation measures, there has been little documentation of their basic information on the ecology and behaviour of the species. Present study, we assessed feeding ecology of the species based on activity budgets, diet (food species, food preferences and food items) and niche breadth using focal animal sampling method. The study was carried out in Peleonan forest, the Mentawai island of Siberut from January 2008 through June 2009 and resulted in more than 2000 contact hours on one group (8 individuals). Results show that activity budget of P. potenziani was dominated by resting (45.7 events/ hour) and feeding (31.8 events/ hour). Meanwhile travelling, foraging, other activity and social behaviour were 6.2, 4.4, 1.3 and 0.6 events/ hour respectively. Regarding diet, P. potenziani used 118 food species in total, however, based on the top ten food species, accounting almost 50% of their overall diets. Average values on food preferences showed that the species mainly fed on fruit, (17.3 events/hour), followed by leaves, flowers and other items (10.8, 1.6 and 1.5 events/ hour respectively). Detailed analysis on food items (certain parts of different plant species eaten) revealed 256 food items in total were eaten by P. potenziani with different feeding proportion. Calculated niche breadths (Levin’s index) of the species revealed a value of 0.22.