Non-volant small mammals of the Western Ghats of Coorg District, southern India

Abstract

A study to understand diversity and changes in non-volant small mammal composition in the Western Ghats of Coorg District, Karnataka was conducted from April 2004 to April 2008. A total of 11060 trap nights of sampling in various habitats such as forest fragments, coffee and cardamom plantations, open areas including grasslands, agricultural fields including paddy and ginger cultivations, bamboo and in and around human habitations across the two vegetation zones of the district. Totally, 14 species of non-volant small mammals were trapped as 412 unique individuals contributing to an overall trap success of 3.8%. Rattus wroughtoni was the most commonly caught taxon followed by Suncus murinus and S. niger although S. murinus was trapped in 10 habitats followed by Mus musculus in 9 of 11 habitats. The abundance of small mammals was the highest in bamboo (12.1%) and in forest fragments (7.2%); the plantations supported very low abundances (< 3.1%). Endemic mammals such as Rattus satarae, Vandeleuria nilagirica, Platacanthomys lasiurus, Funambulus tristriatus and Suncus niger were recorded in Coorg although P. lasiurus and V. nilagirica were trapped in only one habitat each. Changes in land use and rapid decline in quality of habitat is pushing the endemics into local extinctions while non-endemic commensals are displacing restricted endemics in disturbed habitats. This study underlines the need for more in-depth rapid assessments in the Western Ghats for the poorly understood small mammals and the initiation of conservation programmes for endemics.