Population status and distribution of the Critically Endangered Bengal Florican Houbaropsis bengalensis in the grassland of Koshi Tappu Wildlife Reserve, Nepal

Abstract

The Bengal Florican Houbaropsis bengalensis is one of the most threatened terrestrial bird species, listed as ‘Critically Endangered’ by the IUCN. This species is protected globally and locally due to very low population (global population is approximately 250–999 individuals), and little is known about its distribution and habitat use. We assessed population status and distribution of floricans in Koshi Tappu Wildlife Reserve, Nepal (KTWR). We surveyed 57 1-km² randomly distributed blocks across the reserve to record as many individuals as possible during their breeding season (March–May). We walked 2,964 transects (52 transects on each block) each of length 1 km on 57 blocks of 1-km² to estimate their population. We surveyed when the birds are most active during early morning (0600–0930 h) and later afternoon (1530–1900 h). We calculated grass importance value index (IVI), grass species composition, grass height, relative frequency of grass species, relative density of grass species, percent of grass ground coverage, presence/absence of human activity, and presence/absence of livestock to assess the habitat condition. We recorded 18 individuals (16 males and 2 females) inside the core of the reserve, where the habitat is dominated by Imperata cylindrica. Human disturbance had a negative impact on occurrence of the florican. We recommend implementing a Bengal Florican-specific conservation action plan to promote community-based conservation and restrict human encroachment in the grassland habitat.