Diversity and Distribution of Birds in the Bharathapuzha river basin, Kerala, India

Abstract

Bharathapuzha River is the second largest, west-flowing river in Kerala, Western Ghats. This river is exposed to high levels of anthropogenic and natural pressures. This study attempts to understand the diversity and distribution of birds in this river basin. The observations were made from October 2017 to July 2019 in 70*1 km2 grids distributed in three strata (i.e., upper, middle, and lower reaches). A total of 262 bird species were recorded from the river basin. The diversity and richness of birds were found high in the upper reaches of the river and the species abundance was found more in the lower reaches. Due to the high turnover of migratory species, the rank abundance model for upper and lower reaches showed a high degree of dominance while middle reaches showed a relatively even distribution of abundances. Deforestation, sand mining, and water pollution were found to be the major threats in the river basin. Hence the results show the importance of the protection and rejuvenation of the ecosystems associated with the river for the conservation of avian diversity in the region.