Population status and habitat ecology of Bristled Grassbird Chaetornis striata in Chitwan National Park, central Nepal

Abstract

A study to determine the population status and assess the habitat ecology of the Bristled Grassbird Chaetornis striata was carried out in Chitwan National Park, Nepal. Using a call playback method to detect Bristled Grassbirds, the total population was estimated at 4,570±1,270 individuals. Bristled Grassbirds were five times more likely to occur in grassland dominated by Saccharum spontaneum than in grassland where other grasses predominated, and their presence was negatively correlated with tree density. Grassland lightly grazed by wild herbivores was found to be three times more likely to hold Bristled Grassbirds than similar grasslands where grazing was assessed as medium, whilst more heavily grazed grasslands used by domestic livestock were avoided. The preference for grasslands at an early successional stage suggests that the loss of such grasslands to scrub could be a major threat to the Bristled Grassbird, which occurs sparingly in lowland grasslands in Nepal below 300 m.