Factors affecting diversity and distribution of threatened birds in Chitwan National Park, Nepal

Abstract

Factors affecting diversity and distribution of globally threatened birds were studied by dividing Chitwan National Park (CNP) into five study blocks consisting of 17 birding routes.  CNP provides major habitats for the feeding and breeding of a large number of migratory birds from many parts of the globe and also plays a vital role in the conservation of threatened species.  We recorded a total of 437 individuals of globally threatened birds belonging to 19 species of nine families and eight orders.  There was considerable variation (F=2.94, df=44.43, p=0.05) in species diversity of threatened birds in different study blocks: the highest diversity was in Block E (Pithauli, Amaltari, and Narayani Island area; H=2.108), followed by Block C (Kasara to Sukibhar area; H=2.047), Block B (Barandabhar Corridor Forest; H=2.033), Block A (Khagendra Malli, Kathar, Sauraha to Old Padampur; H=1.744), and Block D with the least diversity (Madi area; H=1.69).  The higher dominance index was found in blocks A (D=0.2407) and D (0.2361) compared to other blocks.  The lower diversity of threatened birds was reported in those blocks (A & D) located nearer to human settlements that experienced higher disturbance.  Presence of livestock and people caused significantly negative effects on species richness and abundance of threatened birds, mainly in Block A.  Distance from roads and villages also had a negative effect on the diversity and abundance of most of the threatened birds.  This study suggests that human disturbance caused a significantly negative impact on the presence, distribution, diversity, and abundance of threatened birds in CNP and adjoining areas.