Ultraviolet vision and foraging in dip and plunge diving birds

Ultraviolet-sensitive vision in long-lived birds.

Long-term exposure to ultraviolet (UV) light generates substantial damage, and in mammals, visual sensitivity to UV is restricted to short-lived diurnal rodents and certain marsupials. In humans, the cornea and lens absorb all UV-A and most of the terrestrial UV-B radiation, preventing the reactive and damaging shorter wavelengths from reaching the retina. This is not the case in certain specie...

Ultraviolet vision and foraging in juvenile bluegill (Lepomis macrochirus)

Ultraviolet (UV) photoreceptors have been reported in a wide variety of freshwater and marine organisms, suggesting that UV vision is prominent in aquatic ecosystems. However, its adaptive significance remains speculative. The present study tested whether the foraging of juvenile bluegill (Lepomis macrochirus) is enhanced in the presence of UV radiation (UVR). Laboratory feeding trials were con...

Ultraviolet sensitivity and colour vision in raptor foraging.

Raptors have excellent vision, yet it is unclear how they use colour information. It has been suggested that raptors use ultraviolet (UV) reflections from vole urine to find good hunting grounds. In contrast, UV plumage colours in songbirds such as blue tits are assumed to be 'hidden' communication signals, inconspicuous to raptors. This ambiguity results from a lack of knowledge about raptor o...

Diving Birds of North America: 4 Comparative Diets and Foraging Ecologies

Ultraviolet vision in birds: the importance of transparent eye media

Ultraviolet (UV)-sensitive visual pigments are widespread in the animal kingdom but many animals, for example primates, block UV light from reaching their retina by pigmented lenses. Birds have UV-sensitive (UVS) visual pigments with sensitivity maxima around 360-373 nm (UVS) or 402-426 nm (violet-sensitive, VS). We describe how these pigments are matched by the ocular media transmittance in 38...