The Cinereous Harrier (Circus cinereus), is a bird of prey found in South America. Its breeding range extends from the Tierra del Fuego through Argentina and Chile to Bolivia, Paraguay and southern Brazil, and across the Andes north to Colombia. Its habitat ranges from lowland marshes to the Andean Altiplano at a maximum altitude of 14,750 feet.
Adults attain a length of 15.75 to 19.66 inches with females being larger than the males. The male’s plumage is dark gray above with black wingtips and a white rump. The underparts are pale gray, with a reddish-brown streaked belly. The female is brown above, with a white rump, cream colored underparts, with a streaked belly similar to the male.
Like other harriers it nests on the ground. Its diet is variable and consists of small rodents and birds, reptiles, amphibians and insects.