RESEARCH ARTICLE

AVIFAUNAL DIVERSITY IN THE KALA OYA RIVER BASIN

Abstract

Kalay oya river basin (KOB) is the third largest river basin in Sri Lanka with 76% of its arealying in the dry zone. A four month survey was undertaken in early 2017 to understand the avifaunal diversity in the KOB to identify priority areas for conservaiton. 192 variable circular plots were sampled in 24 transectslocated ineight sub basins. 188 species of birds belonging to 59 families were observed, which included nine endemics, one proposed endemic and 46 migrant species. Of the total birds, 70 (including 30 migrants) can be considered as wetland associated species. Among them the most commonly occurring families were Scolopacidae (13 species), Ardeidae (11 species) and Charadriidae (8 species). The most abundant bird species with highest population densities were Pycnonotus luteolus, Stigmatopelia chinensis, Pycnonotus cafer, Nectarinia zeylonica, Acrocephalus dumetorum and Aegithina tiphia. Four nationally threatened and two globally threatened species were recorded. Of the two globally threatened species only Leptoptilos javanicus is considered nationally vulnerable, while Ciconia episcopus status is near threatened, indicating its population is more stable in Sri Lanka.

The highest species diversity were recorded from Transects that included both aquatic and terrestrial habitats: Nabatayagama Tank and associated forests located adjacent to Namal Uyana Conservation Forest recorded the highest bird diversity followed by Manawa tank associated habitats.The survival of birds are threatened by many anthropogenic activities as well as climate change related droughts. The sub basins that need priority in terms of conserving the bird diversity are Eluwankulama, Manawa kanda and Galpaya sub-basins as well as Eilie sub basin as it is important feeding ground for migratory waders. Continuous monitoring of the bird populations should be undertaken, while attention should be given to maintain adequate tree cover required for roosting and nesting purposes. The importance of wetlands for maintaining the rich biological wealth need to be given priority when allocating water for various development initiatives.

Keywords: Avifauna, diversity, Kala Oya river basin, threats, conservation

How to Cite: Perera,N.M.P,Sumanapala,A.P,Padmalal,U.K.G.K, (2018). AVIFAUNAL DIVERSITY IN THE KALA OYA RIVER BASIN.WILDLANKA, 6(2):Pages 066-075

Published On:2018-06-30

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