It has a total length of 50–65 cm and a wingspan of 120–132 cm. Weight is 0.9-1.6 kg, averaging in 7 birds from Tierra del Fuego. Individuals from the colder southern part of its range average larger than those from tropical regions and are the largest type of caracara. In fact, they are the second largest species of falcon in the world by mean body mass, second only to the gyrfalcon. The cap, belly, thighs, most of the wings and tail-tip are dark brownish, the auriculars, throat and nape are whitish-buff, and the chest, neck, mantle, back, uppertail-coverts, crissum and basal part of the tail are whitish-buff barred dark brownish. In flight, the outer primaries show a large conspicuous whitish-buff patch, as in several other species of caracaras. The legs are yellow and the bare facial skin and cere are deep yellow to reddish-orange. Juveniles resemble adults, but are paler, with streaking on the chest, neck and back, grey legs, and whitish, later pinkish-purple, facial skin and cere. It can be separated from the similar northern caracara by its more extensive barring on the chest, brownish and often lightly mottled/barred scapulars, and pale lower back with dark barring. Individuals showing intermediate features are known from the small area of contact in north-central Brazil, but intergradation between the two species is generally limited.
Behavior
A bold, opportunistic raptor, the southern crested caracara is often seen walking around on the ground looking for food. It mainly feeds on carcasses of dead animals, but will steal food from other raptors, raidbird nests, and take live prey if the possibility arises, it may also eat fruit. It is dominant over the black and turkey vulture at carcasses. It is typically solitary, but several individuals may gather at a large food source. Breeding takes place in the austral spring/summer in the southern part of its range, but timing is less strict in warmer regions. The nest is a large open structure, typically placed on the top of a tree or palm, but sometimes on the ground. Averageclutch size is two eggs.
Distribution and habitat
The southern crested caracara occurs from Tierra del Fuego in southernmost South America north to the Amazon River region and southern Peru. An isolated population occurs on the Falkland Islands. It avoids the Andean highlands and dense humid forest, such as the Amazon rainforest, where it is largely restricted to relatively open sections along major rivers. Otherwise, it occurs in virtually any open or semi-open habitat and is often found near humans.