Birds have four spectrally distinct types of single cones that they use for colour vision. It is often desirable to be able to model the spectral sensitivities of the different cone types, which vary considerably between species. However, although there are several mathematical models available for describing the spectral absorption of visual pigments, there is no model describing the spectral absorption of the coloured oil droplets found in three of the four single cone types. In this paper, we describe such a model and illustrate its use in estimating the spectral sensitivities of single cones. Furthermore, we show that the spectral locations of the wavelengths of maximum absorbance (λmax) of the short- (SWS), medium- (MWS) and long- (LWS) wavelength-sensitive visual pigments and the cut-off wavelengths (λcut) of their respective C-, Y- and R-type oil droplets can be predicted from the λmax of the ultraviolet- (UVS)/violet- (VS) sensitive visual pigment.
|Number of pages||12|
|Journal||Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology|
|Publication status||Published - Apr 2005|
- Bird vision
- Cone photoreceptors
- Oil droplets
- Spectral sensitivity