 The Andean cock-of-the-rock is a large passerine, approximately 32 cm (13 in) long and weighing around 265 grams (9.3 oz; 0.584 lb), although males are somewhat larger and the heaviest specimens can reach 300 grams (11 oz; 0.66 lb). The birds is one of many birds species to exhibit marked sexual dimorphism. The male has a large disk-like crest and brilliant scarlet or orange plumage. It has black tail and wings, and pale greyish scapulars. The female is significantly drabber and browner than the male and has a less prominent crest. The bill is yellowish in the male, and dark with a small yellow tip in the female. Depending on gender and subspecies there are significant variations in the colour of the iris, ranging from red over orange and yellow to bluish-white in the male, and whitish over reddish to brown in the female. In addition to the display calls described in the breeding section below, foraging birds give a loud querulous “ tank? ” when disturbed or in flight.
