DIVERSITY OF AVIFAUNA IN DIFFERENT HABITATS OF THE WASGOMUWA NATIONAL PARK

Abstract

Wasgomuwa National Park (WNP) is the fourth largest National Park in Sri Lanka.Location of this protected area in between the intenoediate zone and dry zone has ~resulted in a mixture of vegetation types. The main objectives of this study were todetermine the avifaunal diversity, distribution, and abundance in different habitats, andprovide infonoation for the scientific management of the WNP.

The survey was carried out at 5 different habitats; grassland, scrubland, riverine forest,and tank. Birds were recorded along a line transect covering 150 X 100 m, with tworeplicates per habitat. Direct observations as well as bird calls were used to confino theexistence of birds in the study sites. Birds were recorded at three different time framesduring the day and each habitat was covered on 21 occasions during the 03 months fieldstudy. TIle species diversity was analyzed under three categories: species richness indices(Margalefs diversity index, Menhinick's index), species abundance model and indicesbased OD the proportional abundances (Shannon diversity index, Simpson's index) ofspecies.The vegetation of each habitat was described by drawing vegetation profiles.

A total of 114 species, belonging to 43 families were recorded from the WNP, during thestudy period. These included 4 endemic species, and 6 species of nationally threatenedbirds. The total number of birds recorded in the study habitats was 4752. The mostdominant order was Passerifomes, represented by 41 species in 19 families. Highestnumber of species was recorded in the riverine habitat and lowest number in thegrassland habitat. The highest number of individual birds was recorded in the tankhabitat and lowest number of individuals was recorded in the grassland habitat. A diurnalvariation of the existence of birds was observed in every habitat. Highest number ofspecies and individual birds were recorded in the morning time frame. The ShannonDiversity index was highest in the riverine habitat and lowest in the grassland habitat.There was a significant difference in diversity among study habitats

This study helped to expand the checklist of birds in the WNP with four new speciesrecords. It was revealed that a mosaic of habitats contribute to an increased avifaunaldiversity as well as their abundance. Therefore to maintain and enrich the bird diversityin a protected area, the wildlife managers should give high priority to conserve andenhance the habitat diversity.