| visual pigments, cone oil droplets and ocular media in four species of estrildid finch. | a microspectrophotometric study was conducted on the retinal photoreceptors of four species of bird: cut-throat finches (amadina fasciata), gouldian finches (erythrura gouldiae), white-headed munias (lonchura maja) and plum-headed finches (neochmia modesta). spectral characteristics of the photoreceptors in all four species were very similar. rods contained a medium-wavelength-sensitive visual pigment with a wavelength of maximum absorbance at 502-504 nm. four spectrally distinct types of single ... | 2000 | 11016784 |