Seriemas

(Cariamidae)

Class Aves

Order Gruiformes

Suborder Cariamae

Family Cariamidae

Thumbnail description
Long legs, tail and neck; short, decurved, hawk-like bill; streaky and barred ashy brown plumage that is soft and loose; wispy, tufted crest on head; long feathers on neck; wings short; toes short and semipalmate (limited or reduced webbing between toes); sexes alike

Size
28–35 in (70–90 cm) in length; 2.6–3.3 lb (1.2–1.5 kg) in weight

Number of genera, species
2 genera; 2 species

Habitat
Grassland, open forest, thorny scrub, savanna-like areas

Conservation status
Not threatened

Distribution
Central and eastern South America

Evolution and systematics

The family of seriemas is an ancient and poorly understood group surrounded by debate regarding taxonomic placement. Birds of this family were previously placed with the secretary bird (Sagittarius serpentarius), which occupies a similar niche in Africa. Based on fossil records, the most likely ancestors are the phorusrhacoids, which were giant, flightless predators of the Tertiary. Today, seriemas are placed within the order Gruiformes (cranes and rails) and are usually grouped closely with the bustards (family Otididae). The closest living relative may be the kagu (Rhynochetus jubatus) of New Caledonia, which shares the presence of a nuchal (an area at the back of the skull) crest, as well as similar displays and vocalizations, but evidence is tentative so far.

Physical characteristics

Both species have similar builds, with elongated bodies; long legs and tails; long necks; and short, rounded wings. The hawk-like bill is stout and hooked at the end. Plumage is ashy brown, finely barred on the upperparts, boldly barred on the flight feathers. The underparts are pale and the abdomen white. Sexes are similar in appearance.

Distribution

Brazil south to Argentina. Ranges of these species may overlap from southern Bolivia through the Paraguayan Chaco to Argentina.

Habitat

Grasslands, open forest, and thorny scrub.

Behavior

Seriemas spend most of the day on the ground, roosting in trees at night. Wary and alert, the birds tend to run rather than fly when startled, with speeds up to 37 mph (60 kph). Dust baths and sunbathing have been observed. Heard more commonly than seen, the birds' loud dog-like yelping may carry for several miles (kilometers). Use of perches, including

trees and termite mounds, help the song travel farther. Duets between pairs are common. The young are capable of singing by two to three weeks of age, then capable of assisting the parents in defending the territory. Disputes may lead to intense vocalization and kicking.

Feeding ecology and diet

Typically foraging alone or in pairs, seriemas stalk their prey deliberately. Groups of three or more are likely to be comprised of parents with young. Seriemas are diurnal hunters with an omnivorous diet that includes insects, small mammals, snakes, lizards, snails, worms, fruits, and vegetable matter. Small prey, such as rodents, is usually pulverized—by slamming onto nearby rocks or the ground—before being swallowed whole. Larger prey, including snakes, may be torn to pieces before feeding. Seriemas are unable to distinguish venomous from nonvenomous snakes and are not immune to venom.

Reproductive biology

Breeding typically occurs between September and May, corresponding with the rainy season. Courtship includes strutting and leaping by the male, as well as displays revealing the hidden pattern of the wings and tail. Seriemas are solitary nesters, remaining distant from other pairs. The nest is comprised of a large platform of sticks and twigs lined with clay or cattle dung. Built in about 30 days by both sexes, it is placed in a tree 3–30 ft (1–9 m) above ground. Nearby branches may allow the adults to jump their way to the nest. Two to three eggs are laid, and these are white to cream with brownish and purplish spots and streaks. The female is the primary incubator for 24–30 days. The downy brown young are able to jump out of the nest and follow the parents at 14 days, although adult weight will not be reached for five months.

Conservation status

Not threatened, although both species occur at fairly low densities throughout their ranges. Potential threats include hunting pressure and destruction of habitat through agricultural development.

Significance to humans

Seriemas are thought to kill large numbers of venomous snakes, although snakes actually make up only a small portion of their diet. Used by some farmers to guard chickens, they warn with a loud alarm call if predators approach. Birds may live up to 30 years in captivity.

Species accounts

List of Species

Red-legged seriema

Cariama cristata

taxonomy

Palamedea cristata Linnaeus, 1766, Brazil.

other common names

English: Crested seriema; French: Cariama huppé; German: Rotfußseriema; Spanish: cariama, siriema, Chuña Pattiroja.

physical characteristics

Red legs and bill, yellow iris surrounded by pale blue bare skin, and a black subterminal bar on the white-tipped tail. Plumage of the neck and underparts is soft and somewhat loose. Long feathers on the hindneck form the nuchal crest, whereas the distinctive frontal crest is formed by permanently raised, stiffened feathers, 3–4 in (7–10 cm) in length, arising from the base of the bill. Sexes similar, but males slightly larger. Juveniles similar, but the bill and legs are blackish, and the markings of the head, neck, and back are more evident.

distribution

More widespread. Inhabits large parts of central and eastern Brazil, Paraguay, eastern and southeastern Bolivia, Uruguay and northeastern Argentina. Elevations up to 6,600 ft (2,000 m).

Primarily savanna-like areas; also open scrub and woodland edges.

behavior

Generally nonmigratory, but temperature-related movement recorded. Rarely fly and spend most of the time on the ground, except for roosting in low trees or bushes. The birds are fast on the ground and can outrun predators. Considered diurnal. Dust bathing is practiced, as well as sunbathing, during which birds of this species lie on their sides, sometimes appearing as if dead. Call is similar to a yelping puppy and can be heard several miles away. Call is usually given in the morning and between pairs, often as a duet between the two birds, to define territory. At the beginning of the call, the head is held straight, but toward the end, the neck is held back so the head nearly touches the bird's back.

feeding ecology and diet

Omnivorous diet including small mammals, insects, snakes, worms, frogs, birds, lizards, snails, fruit, and vegetable matter. May eat eggs or chicks of other species. Slams large prey on rocks to pulverize to make it easier to swallow. The arrangement of their toes prevents them from catching prey with their feet. Forage in small groups or pairs.

reproductive biology

Nests are in bushes or low trees from ground level to 10 ft (3m) up in a tree; sticks are used for building material with mud and leaves for the lining. Both sexes build the nest, which generally takes a month. The male's courtship display involves showing off flight feathers by stretching them to one side and strutting before the female with head down and crest raised. Seriemas are considered monogamous. Clutches usually consist of two white eggs with irregular brown streaks. Incubation lasts for 25–28 days with both parents involved. Chicks fledge in a month.

conservation status

Not threatened, though uncommon in far southern parts of Brazil; rare and possibly vanishing in Uruguay. A population in northeast Argentina appears to be pressured by hunting and destruction of habitat. Has begun to colonize deforested, grassy areas of Amazonian Brazil.

significance to humans

Occasionally offered for sale by illegal traders in parts of Brazil. Farmers often use them as watchdogs for their domestic fowl because of their call.

Black-legged seriema

Chunga burmeisteri

taxonomy

Dicholophus burmeisteri Hartlaub, 1860, Argentina.

other common names

English: Lesser seriema, Burmeister's seriema; French: Cariama de Burmeister; German: Schwarzfußseriema; Spanish: Chuña Patinegra.

physical characteristics

Sexes similar. Blackish legs and bill, red iris, two broad black bars before a narrowly tipped tail. Frontal feathers are hair-like at the tip, but frontal crest is not distinctive. Juveniles are similar to adults, but with distinct barring of the head, foreneck and breast, and white spots along the back and wing coverts.

distribution

East and southeast Bolivia, Paraguay, northwest Argentina.

habitat

Lowland open, dry wooded areas, grasslands, and thorny scrub.

behavior

More sedentary than red-legged seriema. Unable to distinguish between venomous and nonvenomous snakes, which can lead to a birds death. Call is loud yelping and has been compared to that of a yelping puppy. Call can be heard several miles away and is usually given early in the morning, most often to define territory between pairs and is often heard as a duet between the two birds.

feeding ecology and diet

Omnivorous diet including snakes, lizards, frogs, birds, small vertebrates, insects, fruit, and vegetable matter. May be found near livestock, eating insects stirred up during passage. Birds slam large prey on rocks to pulverize. Forages in pairs or small groups.

reproductive biology

Nests are compact, made of sticks, and are built anywhere from ground level up to 10 ft (3 m) in a tree. Little else is documented on this species; however, they are likely similar to red-legged seriema.

conservation status

Not threatened. Listed as still fairly common in Argentina, but documentation elsewhere is poor. May be more likely to be threatened in the future due to the smaller range.

significance to humans

Although egg-collecting and hunting are uncommon, the species has been hunted by natives of the Paraguayan Chaco. Farmers also place the species with chickens to signal the alarm when intruders approach, and to kill snakes.

Resources

Books

Gonzaga, L.P. "Family Cariamidae (Seriemas)." In Handbook of the Birds of the World. Vol. 3, Edited by J. del Hoyo, A. Elliot, and J. Sargatal. Barcelona: Lynx Edicions, 1996.

Sick, H. Birds in Brazil. Princeton: Princeton University Press, 1993.

Blake, Emmett R. Manual of Neotropical Birds, Vol. I. Chicago: The University of Chicago Press, 1977.

Other

Bird Biographies, Black-legged Seriema, Red-legged Seriema. Natural Encounters Inc. 27 Feb. 2002. <http://www.naturalencounters.com/abby4.html>

Birds of the World, Seriemas. Department of Ecology and Evolutionary Biology, Cornell U. 27 Feb. 2002. <http://www.eeb.cornell.edu/winkler/botw/cariamidae.html>

Pamela D. Lewis