Reassessment of the distribution and the threat status of the Western Ghats endemic bird, Nilgiri Pipit Anthus nilghiriensis.

Abstract

Montane grasslands in India face threats from habitat modification and climate change, but have received little conservation attention. In the Western Ghats, 55–80% of this habitat has been converted to commercial and non-commercial plantations. We examine the distribution of a range-restricted, grassland-endemic bird, the Nilgiri Pipit Anthus nilghiriensis through both fieldwork and literature survey. We combine our mist-net-based capture data with museum records that appear to indicate a smaller distributional range for the species than indicated by secondary sighting records. We argue that the species is limited to grasslands above 1900 m. Using GIS methodology, we estimate the area of this habitat to be only 441 sq. km. Spread over just two mountain-tops, our analyses indicate a drastic reduction from the presently projected distribution, making this species one of the most restricted-range birds in India. We discuss potential causes for this discrepancy, including misidentification, which may mislead potential conservation action for such threatened birds. We propose palaeoclimatic changes to be the cause for the present distribution limit to the two large mountains (Nilgiris hills and Anamalai-Palani hills), while anthropogenic habitat modifications may limit the distribution at a finer scale within these mountains. Given the combined effect of historical large-scale landscape modification in this region and the possibility of climate change affecting this species, the Nilgiri Pipit and its habitat appear to be under considerable threat and the bird requires urgent conservation measures, starting with an elevation of IUCN threat level to 'Endangered'.