Diversity, Abundance and Habitat Utilisation of Birds in Periphery of the Mihintale Sanctuary

Abstract

Mihintale sanctuary is one of the important forest reserve located in Sri Lanka with scarceinformation on avifauna. Although this area has been subjected to anthropogenic activities,periphery areas provide more suitable habitats for different species of birds includingmigrants. Current study is carried from July 2010 to end of February 2012 in the Faculty ofApplied Science premises (disturbed) and remnant grass patch habitats locates adjacent to theMihintale forest to investigate the abundance species diversity, and habitat utilisation of birdspecies in two different habitats. Belt transect method (500 x 50 m), point counts and theopportunistic observation method were used for data collection. Vegetation analysis weredone by using quadrates sampling method and habitat utilisation data were gather by scansampling method. Shannon-Wiener Diversity Index and Margalef’s Diversity Indices werecalculated in order to determine the species diversity and richness.

A total of 68 and 99 species belonging to 34 and 42 families were recorded from bothdisturbed and remnant grass patch nearby Mihintale Sanctuary. Among them 64 (94.2%)breeding residents and 4 (5.8%) winter visitors recorded in disturbed habitat while 87(87.8%) breeding residents and 12 (12.2%) winter visitors recorded in grass patch. In bothhabitats 7 endemic species were recorded. Out of the total species 45 species from grass patchand 69 species from disturbed area were common.

Shannon Diversity Index (H') for disturbed and grass patch habitat were 2.48 and 2.76respectively. The results indicated that the diversity avifauna significantly (p=0.0237) higherin the grass patch. Mainly the observed bird species in the study area can be categorized intoseven trophic guilds. The majority was insectivores in both habitats (54% and 41.96%). 22and 19 species of plant were predominantly utilised by the birds inhabited the grass patch andin disturbed area respectively. During the breeding period majority of birds utilised all theplant species in grass patch for nesting while disturbed habitat used for collecting nestingmaterials. Ficus species were recorded as common feeding tree in both habitats. As birds areuseful indicator species of the health of an ecosystem they can be used as focal species togather data on status of habitat and disturbances. This will lead to conservation of birds andtheir habitats.