The visual pigments of several species of birds

Abstract

Retinal preparations were made from the outer segments or whole retinas of 20 species of birds. The oil droplets were extracted with petroleum ether, and the visual pigments either with digitonin or with Triton X-100. The visual pigment samples were analyzed by the method of partial bleaching. Fourteen species each yielded but one visual pigment, ranging in absorbance maximum from 500 nm to 506 nm. Five other species each yielded a predominant visual pigment with λ max near 502 nm, and also a second photopigment with λ max ranging from ca. 480 nm to 490 nm. One species yielded no measurable photopigment. No evidence was obtained for the presence of any cone pigments. The oil droplets were analyzed spectrophotometrically and exhibited inter se similar absorbance spectra.