Anatomical observations on the bill of the Oystercatcher (Haematopus ostralegus occidentalis) in relation to feeding behaviour



Oystercatchers have recently increased as inland breeders in Northern Britain. Concurrently, they have been observed feeding in coastal fields in winter. It is suggested that the bill of this species possesses dual characteristics enabling them to feed on shellfish adn also to probe in the soil for terrestrial invertebrates.

The gross internal morphology of the bills of adults and young is described. A bony core contains large nerves running the length of the bill. These break up towards the tip where numerous sensory corpuscles are seen. It is concluded that the possession of a strong bone core together with numerous sense organs at the tip has been of considerable importance in enabling the Oystercatcher to exploit inland situations.