Wintering Harriers in a Rapidly Changing Landscape in Southern Tamil Nadu, India

Wintering ecology of many migrant bird species, especially migrant raptors is poorly studied. The semi-arid regions of southern Tamil Nadu (TN), India are a major wintering area and the southern limit for many migrant species. Historically there has been a loss of several grassland species from the area and currently, the natural grasslands are completely transformed. There are no studies on grassland birds in the region, especially on migrant harriers, which are grassland species and show a declining trend in most parts of the country. The present study is an effort to identify harrier roosts and record their numbers at the roost sites, during four winters from 2015 to 2019 in the districts of Tirunelveli and Thoothukudi in TN. Three species of harriers were recorded from 16 roost sites and roost counts at these sites varied from 75 to 2. The total number of harriers declined over the survey period and this was consistent across sites. Majority of the roosts were on private land and loss of roost sites to various land-use transformations is a major driver of harrier numbers in the area. Innovative approaches to protect and conserve grasslands are the need of the hour for the future of grassland species in the region.