Food plant diversity in different-altitude habitats of Hainan gibbons (Nomascus hainanus): Implications for conservation

Abstract

Knowledge of habitats and food distribution patterns of Hainan gibbon (Nomascus hainanus) is essential for developing an effective conservation management for the threatened species. Despite having been rediscovered nearly a decade ago, very little is known about its food resources or habitats. In this study, we assessed differences in the food plant diversity as well as identifying the dominant species of food plants between the high- and low-altitude habitats of Hainan gibbons. We particularly focused on large trees (DBH ≥ 10 cm) because they are recognized to provide abundant fruit resources and good environments to gibbons. Results showed that food plants richness, and large food plants richness with abundance at high-altitude habitat were significantly higher than low-altitude ones.The species similarity between the two habitats was low, exhibiting rich berry food plants in the primary mountain rainforest and rich nut-type food plants in the secondary lowland rainforest, respectively. The findings suggest that the high-altitude forests are the current optimal habitat for gibbons which should be strictly protected for the survival of Hainan gibbons. The low diversity of large trees in the low-altitude secondary forests highlights the importance of large food plants for the development of secondary lowland rainforest as potential habitats for Hainan gibbons.