BIRDS—continued.
Discussion why the males alone of some species, and both sexes of other species, are brightly coloured—On sexually-limited inheritance, as applied to various structures and to brightly-coloured plumage—Nidification in relation to colour—Loss of nuptial plumage during the winter 154-182
The Descent of Man and Selection in Relation to Sex, Vol. Ii (1st Edition) · The Wunder Library — complete classics, free to read, with narration.