Patterns of distribution and multiscale-habitat correlates of riverine birds in the upper Ganges, Western Himalaya.

Abstract

Fauna associated with riverine ecosystems vary considerably at the global scale ranging from obligate terrestrial to obligate aquatic. Birds constitute key components of wildlife along running water systems. 2. The global river bird community is diverse with 66 species, spanning across 19 families with 37 non-passerines and 29 passerines. Asia has the maximum number of species followed by South America and Africa. 3. The global distribution ranges of specialist river birds show that large areas of the world hold few or no specialist riverine birds. Richness peaks in the eastern Himalaya and the Myanmar-China border, around the Kakabo Raazi mountains where more than 15 species of specialist river birds overlap in range. 4. Species richness reflects considerable radiation in particular groups; Muscicapidae (small passerine insectivorous birds mostly belonging to the old world) in Asia, ovenbirds (Funariidae) and tyrant flycatchers (Tyrannidae)in South America, and the Pratincoles (Glareolidae) in Africa. 5. Ecological understanding and conservation efforts of specialist river birds remain rudimentary especially in the tropics where rivers are faced with a host of threats. 6. In this particular study, field surveys were undertaken to understand bird community composition and river habitat characteristics across summer (breeding) and autumn (wintering/non-breeding) seasons in the Bhagirathi basin, a major headstream of the Upper Ganges in the state of Uttarakhand in the western Indian Himalaya between years 2014 and 2018.