Feeding Repertoire of the Boat-Billed Heron (Cochlearius cochlearius)

Abstract

The Boat-billed Heron's (Cochlearius cochlearius) atypical bill has inspired a half-century of literature addressing its possible ecological and evolutionary implications. Based on a review of this literature and results of a field study conducted in San Blas, Mexico, it can be concluded that the Boat-billed Heron is nocturnal, visuallyfeeding, with a limited and simple feeding repertoire and diet. The heron forages by standing on branches and roots and by walking slowly in shallow water capturing fish and shrimp by lunging and by scooping the surface of the water with its bill. Except for scooping, the feeding repertoire is unexceptional and moreover is typical of other herons that feed by perching on low-hanging branches. Similarly, its food is similar to other nocturnal herons feeding in the same place. Herons obtained about 60 prey items per day. Thus the outlandish bill appears not to be detrimental to the bird's foraging successfully in a manner typical of herons using similar habitat. The bill has been shown to be used in social signaling, which may be its primary contemporary function. Based on available information the exceptional bill of the Boat-billed Heron appears to have few, if any, systematic or ecological implications.