Cloud Forest Dung Beetles (Coleoptera: Scarabaeinae) in the Western Ghats, a Global Biodiversity Hotspot in Southwestern India

摘要

First-time comprehensive data on the community structure, species composition and regional endemism of dung beetle assemblage in a tropical montane cloud forest (TMCF) from South Asia is provided. High level of endemism, predominance of two montane endemic species of which one is a flightless local endemic, greater proportional abundance of roller guild, and the total absence of dweller guild, make the cloud forest dung beetle community different from the communities in the low-altitude montane forests. Distribution of major proportion of montane species in the low altitude supports the hypothesis for the origin of montane fauna through vertical colonization of the high altitudes by low-altitude species. Abundance of rollers is attributed to the availability of dung pellets of local endemic mountain goat, Nilgiri Tahr (Nilgiritragus hylocrius) and Sambar deer (Cervus unicolor) throughout the year and absence of dweller guild to the seasonal availability of fresh dung pads of Asian elephant (Elephas maximus) and gaur (Bos gaurus). Dominance by the flightless local endemic dung beetle Ochicanthon devagiriensis, belonging to the old-world tribe Canthonini with Gondwanaland distribution, indicates the stability, refugial isolation, and archaic nature of the dung beetle assemblage in the studied montane region. Since flightless species show a high level of fidelity to their preferred habitat and are efficient indicators of historical changes in their habitats, dominance and local endemism of flightless species Oc. devagiriensis makes it an ideal indicator species and effective forecaster of habitat modifications of the unique cloud forest study region in the Western Ghats.