Graham Martin and Steve Portugal (Centre for Ornithology) have been working in collaboration with Twycross Zoo (Leicestershire), Birdworld (Surrey) and the Wildfowl and Wetlands Trust (Slimbridge, Gloucestershire) to investigate the relationship between visual fields and the bill tip sensory organs in ibises and spoonbills. Prior work has demonstrated that aquatic foraging ibis have many more touch sensor receptors in their beak compared to related ibis species which are terrestrial foragers. This is assumed to be in response to the differences in the foraging environment and the availability of visual cues for foraging. An ibis foraging in turbid water can not see its prey, and therefore, relies on touch sensitivity in the beak to locate food. We are studying how the visual field parameters in the ibises and spoonbills are adapted both to their foraging environment and to the degree of touch sensitivity in their beaks. (photos show a close up of an eye of Scarlet Ibis and the head of a Puna Ibis; Scarlet Ibises are mainly aquatic foragers, Puna Ibises are mainly terrestrial)
