Conservational significance of Dunumadalawa Forest Reserve in Central Sri Lanka based on the endemism of its avifauna

Abstract

The concept of endemism is useful in evaluating the biological significance and uniqueness of an area. It is a meaningful alternative to simple species richness and can be used as a relevant measure in assessing conservational significance. Dunumadalawa (7o17'00"N; 80o38'49"E; 548-972 m above sea level) is a semi-isolated, hill country wet-zone forest reserve located in Kandy District, Sri Lanka. It is approximately 480 ha in extent, and comprises mainly of secondary growth forest. The objective of the present study was to determine the level of endemism of its avifauna to justify its conservational significance. The study was carried out from January to September, 2015. A line transect integrated with a point count method was used to collect data. Peak sampling hours were between 0600-0900 h and 1500-1800 h in sites selected by systematic random sampling. Density estimation was done using Distance® software. As a control, results were compared with those of nearby home gardens. According to Shannon (H’) and Simpson (1-D) Diversity Indices avifaunal diversity in Dunumadalawa was comparatively higher (H¢ = 3.56, (1-D) = 0.959) than that of the home gardens (H¢ = 2.98, (1-D) = 0.923). Dunumadalawa harbours 13 out of 33 endemic bird species in Sri Lanka (39.4 %) and 29 endemic subspecies out of 68 (42.7 %). The forest is also refuge for 10 of the 23 (43.5 %) restricted range bird species. Due to the presence of endemics and restricted range species, Dunumadalawa, which serves as a habitat island in the midst of a large urban area, merits special conservation attention.

Keywords

• endemic birds, diversity, threats, conservation, dunumadalawa forest