Kamichi à collier

En bref

  • Scientific Name: Chauna torquata
  • Nom espagnol : Chajá
  • Famille : Anhimidae
  • Known Nicknames: Crested Screamer, Chajá
  • Average Length: 83–95 cm / 33–37 in
  • Average Weight: 3.5–5.0 kg / 7.7–11.0 lb
  • Wingspan: 150–170 cm / 59–67 in
  • Key Feature: Prominent fleshy crest at the back of the head and two sharp spurs on the wings
  • Primary Diet: Primarily Herbivore
  • Range: Southeastern Peru, Bolivia, Paraguay, southern Brazil, Uruguay, and northern Argentina
  • Habitat: Wetlands, marshes, flooded grasslands, and lagoons
  • Social Structure: Social, often found in pairs or small flocks
  • Nesting/Breeding: Ground nests built in dense vegetation near water
  • Statut de conservation : Préoccupation mineure (LC)
  • Évolution démographique : Stable

The Southern Screamer (*Chauna torquata*) is a large, prehistoric-looking waterbird native to South American wetlands, renowned for its piercing, far-carrying alarm call that gives it its name. Standing up to three feet tall, it resembles a long-legged goose with a stout, chicken-like beak, but is distinguished by a fleshy, red cartilaginous spur on each wing used in fierce territorial fights. Its plumage is mostly soft gray with a striking white cheek patch and a distinctive black-and-white ring around its neck, while its feet are only partially webbed—an adaptation for perching in trees, unlike most waterfowl. A unique feature is its ability to produce its loud scream thanks to a specialized, non-muscular syrinx, and it is one of the few bird species that can digest tough aquatic plants with the help of symbiotic gut bacteria, making it a fascinating, vocal icon of its marshy ecosystem.

Faits amusants

Despite their name, Southern Screamers can’t truly scream—their call is a loud, far-carrying, two-note honk that sounds more like a goose with a megaphone than a bird in distress. They have two sharp spurs on each wing, which they use like switchblades in fierce territorial fights with rivals or to defend against predators. Unlike most waterfowl, their toes are only slightly webbed, making them clumsy swimmers but excellent walkers and runners through marsh grass. They are also one of the few birds with a built-in “air conditioner”: they can control blood flow to their bare, red facial skin to regulate body temperature, flushing brighter when hot or stressed.

Habitats et répartition

The Southern Screamer inhabits tropical and subtropical lowland wetlands, including freshwater marshes, flooded grasslands, lagoons, and the margins of slow-moving rivers and lakes. It prefers areas with dense emergent vegetation, such as reeds and rushes, which provide cover and nesting sites, and is often found in open, seasonally flooded savannas like the Pantanal. Its geographical range extends across central and southeastern South America, from southern Bolivia, Paraguay, and southern Brazil through Uruguay to east-central Argentina, occurring primarily east of the Andes.

Comportements & Reproduction

Southern screamers are monogamous and form strong, long-term pair bonds that are reinforced through synchronized duet calls and elaborate mutual displays, including head-wagging and wing-flapping. Their social structure is primarily based on the mated pair, though they may gather in loose, non-breeding flocks during the non-breeding season. Mating involves the male performing a courtship dance around the female, and after copulation, the pair builds a large, floating nest of reeds and vegetation in shallow water. A unique reproductive strategy is their cooperative chick-rearing: both parents share incubation duties for about 42–45 days and, once hatched, the precocial chicks are fiercely guarded by both adults, often riding on the parents' backs for protection and warmth, a behavior uncommon among most waterfowl.

Alimentation

The Southern Screamer is primarily herbivorous, with its diet consisting almost entirely of aquatic vegetation such as roots, stems, leaves, and seeds of water plants like water hyacinths and grasses. Unlike many waterfowl, they rarely eat animal matter, though they may occasionally consume small insects or snails. A fascinating aspect of their diet is that they lack the ability to filter food through their bills like ducks, instead using their sharp beaks to tear and clip plants. Additionally, because their food is low in calories, they spend a significant portion of their day foraging, and their specialized digestive system includes a large gizzard to help break down tough, fibrous plant material.

Couleurs

The Southern Screamer has predominantly gray plumage, with a blackish neck collar and a white cheek patch. Its head is small and gray, contrasting with a red or pinkish bare facial skin and a short, hooked gray bill. The legs are bright pinkish-red. It lacks cryptic camouflage, relying instead on its large size and loud alarm calls for defense.