Blue tits are ultraviolet tits
Publication Type: |
Journal Article |
Year of Publication: |
1998 |
Authors: |
Sarah Hunt, Andrew T. D. Bennett, Innes C. Cuthill, Richard Griffiths |
Publication/Journal: |
Proceedings of the Royal Society B: Biological Sciences |
Keywords: |
blue tit, female choice, sexual dichromatism, sexual selection, spectral reflectance, uv vision |
Abstract:
The blue tit (Parus caeruleus) has been classified as sexually monochromatic. This classification is based on human colour perception yet, unlike humans, most birds have four spectrally distinct classes of cone and are visually sensitive to wavelengths in the near-ultraviolet (300 to 400 nm). Reflectance spectrophotometry reveals that blue tit plumage shows considerable reflection of UV light. For example, the blue crest shows peak reflectance at wavelengths around 352 nm. Furthermore, the blue tit is sexually dichromatic for multiple regions of plumage, including the crest. Choice trials performed in the laboratory indicate that females prefer males with the brightest crests. This study has implications for both intra- and interspecific studies of sexual selection, as well as future classification of dichromatism, which should not ignore the possibility of variation in reflectance in the UV.