The black-collared hawk (Busarellus nigricollis) is a species of bird of prey in the family Accipitridae. It is monotypic within the genus Busarellus. It has a widespread range of presence, from western Mexico to Uruguay. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical swamps, and swamps. The adult black-collared hawk has a more or less white head, tinged with buff, and with black shaft streaks on the crown. The body, above and below, and the mantle are bright cinnamon-rufous, paler on the chest. There is a black crescent on the upper breast. The back has scattered black shaft stripes; the flight and tail feathers are black with the base of the tail barred with rufous. The eyes are bright reddish brown, the cere and bill black, and the legs bluish white. Immatures are similar, but blotched with black, including on the crown, and the rufous barring on the tail is more extensive. The pale area on the chest is also more clearly marked. The upper surface of the wings is barred, and the eyes are brown.
It is found in Argentina, Belize, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Suriname, Trinidad and Tobago, Uruguay, and Venezuela. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical swamps, and swamps. The black-collared hawk lives on a diet mainly composed of fish. It also eats water bugs and occasionally lizards, snails and rodents. It is classified as least concern by IUCN.