There are just three species of Screamers (Anhimidae) including the Horned Screamer, Northern Screamer or Black-necked Screamer, and Southern Screamer or Crested Screamer.
Screamers are large ungainly birds which are distantly related to wildfowl. They are wading and swimming birds and walk very slowly and deliberately. These birds have a bony spur on the carpal joint of the wing which can be used to defend itself. They are strong fliers and feed on mainly vegetable matter.
All three species are found in South America. The Horned Screamer and Southern Screamer are widespread and fairly common while the Northern Screamer is relatively rare and considered 'near threatened'.
Screamers are large bulky birds with a small head, long legs, and large partially webbed feet. They live in open areas, marshes, and feed on aquatic plants. They give out a loud scream when they are threatened. They are rarely hunted as the meat is highly unpalatable.
Horned Screamer: The Horned Screamer has a black head with a whitish crown and long curved feather sticking out from the top of the head, a short dark-grey hooked beak, yellow eyes, the upperneck, breast, upperparts, flanks and tail are black with a glossy green sheen, the lowerneck is speckled with white, the abdomen and underwing coverts are white, there are two sharp spurs on the black wings, and the legs and partially webbed feet are grey. Both sexes are alike with the male usually being slightly larger.
Northern Screamer: The Northern Screamer has a grey crown with a tuft of grey feathers extending from the nape, a white throat extending to the cheeks, bare red skin from the brown eye to the small grey hooked beak, a black neck, blackish-grey breast, upperparts and flanks, slightly paler underparts, a black tail, there are two sharp spurs on the blackish-grey wings, and legs and partially webbed feet are pink. Both sexes are alike with the male usually being slightly larger.
Southern Screamer: The Southern Screamer or Crested Screamer has a large grey body with some black and brown feathers, a small grey head with tufts of feathers at the back, a short hooked beak, a black ring around the neck, and bare red skin can be seen from the base of the beak to the eye. Their pink feet are only partially webbed. Both sexes are alike with the male usually being slightly larger.