CARIAMIDAE Seriemas FAUNA PARAGUAY

CARIAMIDAE - SERIEMAS

Two global species in monotypic genera confined to the Neotropics and both occurring in Paraguay. Seriemas are the closest living relatives of the great predatory birds that once inhabited the plains of South America and the oldest known fossils belonging to the family date from the Paleocene of Brazil. Today they are amongst the largest ground-dwelling birds in South America, occurring in arid, semi-open areas, Chunga being more associated with woodland and Cariama with open grassland. Despite a superficial similarity to the African Secretarybird (Sagittaridae) there is no close relationship and despite considerable discussion the current consensus is that they are related to the Cranes (Gruidae) and Rails (Rallidae). The family name comes from the Guaraní name Cariama, which means "one with erect crest".
Seriemas have loose-webbed plumage and the feathers of the hind-neck and forehead are elongated. The neck and legs are long with bare tibiae. The bill is fairly long and strong with a downcurved culmen and raptorial, hooked tip. The plumage is predominately greyish or brownish with a paler underside. The wings are rounded, though they fly only when necessary and only for short distances - with several strong flaps followed by a glide. Three short toes face forwards and there is an elevated hind toe each armed with sharp claws, but meaning that the feet are incapable of gripping objects. Seriemas run strongly and are capable of reaching speeds of up to 70 km/h. They are diurnal, social birds, living in small groups. One of the most notable characteristics of the family is the loud yelping call which may carry for several kilometres and is most often heard in the early morning. Singing birds open the bill wide and throw the head back over the back, often calling in duet or chorus.
Though seriemas have a reputation for being snake killers, snakes actually form only a small part of the diet and the belief that they are immune to snake venom is false. In fact arthropods form a greater part of their diet. Prey items may be beaten against the ground, stepped on with the feet and torn to pieces, or swallowed whole head first. Captive birds have lived for over 30 years.
Seriemas are solitary breeders and nest in trees, though they choose sites that can be jumped into too, or reached by scaling the tree trunk - ie without having to fly. Nests are built by both sexes but incubation is performed primarily by the female. Chicks are nidicolous and are fed by both parents. Juveniles join in the singing with parents by 2 or 3 weeks of age. The sexes are alike and juveniles resemble adults.

REFERENCES
Campbell B & Lack E 1985 - A Dictionary of Birds - T & AD Poyser.
Gonzaga LP 1996 - Cariamidae Handbook of the Birds of the World Vol 3 - Lynx Ediciones.