Food-Niche Partitioning among Sympatric Kingfishers in Bhitarkanika Mangroves, Odisha

Abstract

The study, conducted from January to May, 2011, attempted to understand the potential mechanisms that may play a role in food-niche differentiation among four sympatric kingfishers, i.e. Small Blue, Collared, Black-capped, and Brown-winged kingfishers in Bhitarkanika mangroves. For foraging behaviour, an individual was followed till it captured a prey and relevant foraging variables were recorded. A total of 53 independent prey captures were recorded for the four species of kingfishers. Perch height and foraging distance differed significantly among the four kingfisher species. All the prey characteristics, i.e., prey type, prey size, and foraging substrate showed significant variations among the species. This study revealed that each of the four kingfisher species in Bhitarkanika mangroves occupy foraging niches corresponding to their respective body size. The foraging behaviour of the smallest species, i.e., Small Blue Kingfisher, and the largest, i.e.. Brown-winged Kingfisher, is similar. The foraging behaviour of the Collared and Black-capped Kingfisher is similar, but they differ in terms of prey size taken, corresponding to their respective body sizes.