Brown-hooded gull

The brown-hooded gull (Chroicocephalus maculipennis) is a species of gull, found in South America in Argentina, southeastern Brazil, Chile, Uruguay, and in the South Atlantic Ocean on the Falkland Islands. Its specific epithet, maculipennis, means 'spotted wings' (macula + penna). Like the other species of the genus Chroicocephalus, it was formerly included in a broad view of the genus Larus.

Adults in the breeding season have a dark brown head and throat with a white semicircle around the posterior of the eye, while the neck, chest and abdomen are white. In winter plumage, the brown hood is largely lost, retaining just a dark spot behind the eye and a dark smudge around the eye. The beak and legs are red, and the eye is dark brown. The outer primary flight feathers are white with black tips (the 'spots' of the scientific name) above and showing more extensively black from below, while the inner primaries and the secondaries and covert feathers are a silvery grey. There is no significant sexual dimorphism, but young birds are distinct, with the wings mottled pale brown, a black bar on the tip of the tail, paler orange-red legs and the bill orange-red with a dark tip. As the plumage is very similar to the closely related black-headed gull C. ridibundus, it has been considered a subspecies of that by some authors in the past, though now universally considered a separate species; they do not overlap in range.