SERIEMAS: CariamidaeRED-LEGGED SERIEMA (Cariama cristata): SPECIES ACCOUNT
Seriemas range in size from about 28 to 35 inches (70 to 90 centimeters) in length and 2.6 to 3.3 pounds (1.2 to 1.5 kilograms) in weight. They have long legs, long tails, long necks, and short, rounded wings. Seriemas have sturdy, hooked bills that resemble those of hawks. Their backs and necks are light brown in color, whereas the belly is pale or white. Male and female seriemas are similar in size and general appearance.
Seriemas are found in central and eastern South America, from portions of Brazil to as far south as Argentina.
Seriemas are found in grassland habitats as well as areas of open forest or brushland.
Seriemas are omnivorous, meaning that they eat both plant and animal matter. They hunt a wide variety of prey, including small animals such as insects, snails, and worms, as well as larger animals such as rodents, snakes, and lizards. These birds frequently smash medium-sized prey, such as rodents, against rocks to make them easier to swallow whole. They tear larger prey into smaller pieces using their strong, sharp bills. Seriemas hunt during the day by stalking, or quietly following, potential prey. They will also eat some fruit and other plant matter.
BEHAVIOR AND REPRODUCTION
Seriemas are often found either alone or in pairs, made up of male and female mates. Sometimes larger groups, consisting of parents with their offspring, are also seen. They spend most of the day on the ground hunting for food. They spend the night in trees. Seriemas tend to run away rather than fly away when threatened. Among birds, they are very fast runners and can achieve speeds as high as 37 miles per hour (60 kilometers per hour). Their call has been described as a yelping noise. Seriemas often stand in trees or on top of termite mounds to call, which helps the call travel further.
Seriemas are territorial, that is, they defend areas of land from other members of the same species. Disputes over territories are decided by intense calling as well as kicking. Offspring often help their parents defend territories by calling.
Seriemas breed during the rainy season, generally between September and May each year. To convince females to mate, male seriemas perform struts and leaps and also show the normally hidden feathers of their wings and tails. Both the male and female help in building the nest, which is made from sticks and twigs and lined with either clay or cattle dung. Nests are usually built in trees and may be anywhere from 3 to 30 feet (1 to 9 meters) above the ground. The female lays two or three eggs at a time, and these hatch after anywhere from twenty-four to thirty days. Offspring are able to leave the nest after two weeks, and reach adult size at five months of age.
SERIEMAS AND PEOPLE
Seriemas are sometimes hunted for their meat. They are also used by humans to guard chicken coops, since they will make loud warning calls if predators approach. Seriemas are also believed to benefit humans by killing a large number of venomous snakes.
Snakes are part of the diet of both species of seriemas. Unlike many snake-eaters, however, the black-legged seriema appears to be unable to tell the difference between poisonous snakes and non-poisonous snakes. They are not immune to snake venom and are therefore sometimes killed by their intended prey. Farmers sometimes keep them in chicken coops to kill snakes, as well as to give warning when predators approach.
The two species of seriemas are not currently considered threatened. However, their populations are declining in some areas due to hunting and habitat destruction.
Physical characteristics: The red-legged seriema has, as its name suggests, red legs. It also has a red bill. The eyes are yellow and surrounded by a patch of featherless blue skin. The tip of the tail is white in color. The feathers are generally brownish on the back and pale on the belly. The red-legged seriema also has a 3- to 4-inch (7- to 10-centimeter) crest of stiffened feathers on top of its head. Males and females are generally similar in appearance, although the males are slightly larger than the females. Juvenile seriemas have black bills rather than red ones.
Geographic range: The red-legged seriema is found in central and eastern Brazil as well as portions of Paraguay, Bolivia, Uruguay, and northeastern Argentina.
Habitat: The red-legged seriema inhabits grassland habitats, as well as open scrub or brushland areas and the edges of wooded forests.
Diet: Red-legged seriemas forage, or hunt for food, in pairs or small groups. They have a diverse diet including animals such as insects, worms, small mammals, frogs, snakes, and lizards, as well as fruit and other plant material. Red-legged seriemas will also eat either the eggs or chicks of other bird species. Some prey are smashed against rocks to make them easier to swallow whole.
Behavior and reproduction: The red-legged seriema spends much of its time on the ground. It rarely flies but prefers to run away from danger. However, they do roost, or spend the night, in trees. Red-legged seriemas sunbathe—they lie on the ground on their sides and appear, sometimes, to be dead. Red-legged seriemas have very loud calls that can be heard as far as a mile away. The call is described as sounding like the yelp of a dog. Calling generally occurs in the morning, as a male and female pair cry out to each other. The purpose of the calling is to defend their territory from other members of the same species.
Red-legged seriemas are monogamous, that is, a single male mates with a single female. They build their nests as high as 10 feet (3 meters) off the ground, usually in a tree. Nest building is a long process for this species, taking up to a month. Both the male and female participate in nest building. Before mating, males show off their feathers by extending their wings. They also strut, walking around with their heads down and their crest of feathers up. The female red-legged seriema lays two eggs at a time. Both parents help incubate, or sit on, the eggs, which hatch after twenty-five to twenty-eight days. Chicks are able to fly after approximately one month.
Red-legged seriemas and people: Humans sometimes use red-legged seriemas in their chicken coops, because they will give an alarm cry if predators approach. Red-legged seriemas are also hunted for their meat.
Conservation status: The red-legged seriema is not currently considered threatened. However, it is declining or disappearing from parts of its range. It is now extremely rare in Uruguay. Argentine populations of red-legged seriemas appear to be declining due to hunting and habitat destruction. ∎
FOR MORE INFORMATION
del Hoyo, J., A. Elliott, and J. Sargatal, eds. Handbook of the Birds of the World. Vol. 3, Hoatzin to Auks. Barcelona: Lynx Edicions, 1996.
Perrins, Christopher, ed. Firefly Encyclopedia of Birds. Buffalo, NY: Firefly Books, 2003.
"Cariamidae (Seriemas)." The Internet Bird Collection. http://www.hbw.com/ibc/phtml/familia.phtml?idFamilia=50 (accessed on April 12, 2004).
"Family Cariamidae (Seriema)." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/classification/Cariamidae.html#Cariamidae (accessed on April 12, 2004).
"Seriemas." Bird Families of the World, Cornell University. http://www.es.cornell.edu/winkler/botw/cariamidae.html (accessed on April 12, 2004).