Prey size choice by captive pied kingfishers, Ceryle rudis L.

This paper examines the choice of prey size by captive pied kingfishers. Experiments consisted of simultaneous choices between two prey items of different sizes presented at three depths. The pied kingfishers chose the larger prey in the majority of trials. The probability of choosing the larger prey ('selectivity') was positively correlated with the relative size difference between prey. Selectivity increased with increased prey depth. Latency to capture was not correlated with relative size difference but increased with increased prey depth. These results suggest that comparison between prey items was more important than absolute prey size in the kingfisher's prey choice. Some unique foraging and visual problems of fish-eating birds are discussed.