Cariamidae – Seriemas

The seriemas are the sole living members of the small bird family Cariamidae, which is also the only surviving lineage of the order Cariamae. Once believed to be related to cranes, they have been placed near the falcons, parrots and passerines, as well as the extinct ‘terror birds’.

The seriemas are large, long-legged terrestrial birds that range from 70cm to 90cm. They live in grasslands, savanna, dry woodland and open forests of Brazil, Bolivia, Argentina, Paraguay and Uruguay.

They forage on foot and run from danger rather than fly (although they can fly for short distances, and they do roost in trees). They have long legs, necks, and tails, but only short wings, reflecting their way of life. They are among the largest ground-dwelling birds endemic of the Neotropics (only smaller than rheas)

Ecologically the seriema is the South American counterpart of the secretary bird. They feed on insects, snakes, lizards, frogs, young birds, and rodents, with small amounts of plant food (including maize and beans). They often associate with grazing livestock, probably to take insects the animals disturb. When seriemas catch small reptiles, they beat the prey on the ground or throw it at a hard surface to break resistance and also the bones. If the prey is too large to swallow whole, it will be ripped into smaller pieces with a sickle claw by holding the prey in the beak and tearing it apart with the claw.

Seriemas build bulky stick nests. They lay two or three white or buff eggs sparsely spotted with brown and purple. The female does most of the incubation, which lasts from 24 to 30 days. Hatchlings are downy but stay in the nest for about two weeks; then they jump down and follow both parents. They reach full maturity at the age of four to five months.

These birds are thought to be the closest living relatives of a group of gigantic (up to 10 ft or 3.0 m tall) carnivorous ‘terror birds’, the phorusrhacids, which are known from the fossil record of South and North America. They are brownish birds with short bills and erectile crests, found on fairly dry open country, the Red-legged Seriema preferring grasslands and the Black-legged Seriema preferring scrub and open woodland. They give loud, yelping calls and are often heard before they are seen. They have sharp claws, with an extensible and very curved second toe claw.