Foraging Behaviour of Sri Lanka Green Pigeon (Treron pompadora) in Tropical Wet Evergreen Forests of Sabaragamuwa Province, Sri Lanka

Abstract

Sri Lanka green pigeon (Treron pompadora) is endemic to Sri Lanka. It is a fairly common breeding resident distributed in lowlands to lower hills. The objective of this study is to determine foraging behaviour including searching behaviour, attack behaviour, foraging sites, food types and food handling techniques. The study was conducted in the Tropical Wet Evergreen Forests of Kiriporuwa (6°48/ 53// N, 80°14/ 13// E) in Sabaragamuwa Province, Sri Lanka. This study was conducted from January 2018 to August 2020. Data collection was carried out in three line transects (100×10 m) using binoculars (Nikon Monarch, 12×42, Japan) from 0630h to 1830h in two days per month. An ethogram was constructed by using observational data. The behaviours for searching food, attacking food, foraging site, food types and food handling techniques were categorised in 380 foraging observations. Diurnal time duration was divided into two-hour time periods. Direct foraging observations and faecal sample analysis methods were used to observe food consumption. Time allocation for foraging behaviour was maximum in 1630h-1830h time period. Flying was the major foraging site movement. Gleaning attack method was used to capture food. They highly
utilised the trunks and main branches of trees as foraging substrates. They foraged in the middle position of the trees and moderate density foliage cover was preferred. They consumed fruit, flower buds, leaves and moss. The diet of Sri Lanka green pigeon was comprised with fruit of the Families of Myrtaceae, Salicaceae, Anacardiaceae, Fabaceae, Moraceae, Clusiaceae, Sapindaceae and Fabaceae. They consumed these fruits by using biting food handling technique. They have arboreal foraging behaviour with complete consumption of plant food. Therefore, it is important to protect the tropical wet evergreen forests to ensure the conservation of this endemic bird species

Keywords: Foraging, Sri Lanka Green Pigeon (Treron pompadora), Endemic bird, Tropical wet evergreen forests, Sabaragamuwa Province