Foraging behaviour of oriental dwarf kingfisher (Ceyx erithaca) in tropical wet evergreen forests of Sabaragamuwa province, Sri Lanka

Abstract

Oriental dwarf kingfisher (Ceyx erithaca) is the smallest kingfisher species in the South Asia. National conservation status of this species is near threatened (NT). The objective of this study was to determine searching behaviour, attack behaviour, foraging sites, food types and food handling techniques of Oriental dwarf kingfisher. The study was conducted in the Tropical Wet Evergreen Forest of Kiriporuwa village (6°48′53′′ N, 80°14′13′′ E) in Sabaragamuwa Province, Sri Lanka. This study was conducted from January 2018 to August 2019. Data collection was carried out in three line transects (100 m × 10 m) using binoculars 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 categorized in 180 foraging observations. Diurnal time duration was divided into two-hour time periods. Time allocation for foraging behaviour was maximum in 0830h - 1030h time period. Flying was the major foraging site movement. There was 43% of successful foraging attacks. Gleaning attack method was used to capture food. They highly utilized the trunks and main branches of trees as foraging substrates. They foraged in the middle position of the trees and very low-density foliage cover was preferred. They consumed insects, millipedes, centipedes, arachnids, molluscs, amphibians and reptiles as food sources. Beating method was the main food handling technique. Adaptation of various diet strategies is the reason for foraging success of this species.