Bird–plant associations along the edges of selected fragmented habitats in southern province, sri lanka

Abstract

Recent development projects taken place all over Sri Lanka seem to cause massive decline in available habitats, habitat fragmentation and edges. Habitat fragmentation and formation of edges threaten survival and reproduction of avifauna. However this has not been widely studied in Sri Lanka. Therefore, the objectives of the present study were to reveal the bird-plant associations in selected fragmented habitats to collect baseline data. Present study has selected edges located at the premises of University of Ruhuna (UP), Matara (5°56'N 80°34'E) and Kirala Kele sanctuary (KK), Matara (5°58' N 80°32' E) and Baruthakanda (BK) a secondary dry zone bush land (6°13'N 81°04' E) situated in Hambantota. Birds, vegetation and bird – plant associations at the study sites were surveyed along transects and established plots (250 m × 25 m) from April- October 2016. Data were analyzed using diversity indices and sites were compared for bird density and plant density using non parametric statistics (Kruskal Wallis Test). Total number of bird species recorded at UP, KK and BK sites were 51, 60 and 59 respectively. Shannon – Wiener diversity was 4.30, 4.25 and 3.63 respectively. Highest mean bird density per unit area was 2101 was observed at BK. Bird and plant densities were significantly different among study sites. (Kruskal Wallis test value – 6.489, P = 0.039). As for the observations in this study, birds used plants mainly for feeding in UP, for nesting and roosting in KK and for resting and nesting in BK indicating the site specificity of the bird-plant associations. As for the comparison with the reference sites, edge specific bird species at UP i.e. Blue – faced Malkoha, Stork – Billed Kingfisher, Yellow – rumped Flycatcher and BK i.e. Bright Green Warbler, Cinereous Tit, Dusky Warbler were recorded. These data further indicate the specificity of the study edges. Specific bird – plant associations were identified in each study site i.e. Asian Koel – Ahu plant in UP, Red – vented Bulbul and Acacia plant in KK and Purple – rumped Sunbird – Katu Andara plant in BK. These data might be useful in terms of the bird conservation especially in setting priorities.