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Toucans

Species of toucans



Toucans are 42 species of familiar, brilliantly colored arboreal birds that make up the family Ramphastidae. Toucans are in the order Piciformes, which also includes the woodpeckers.



Toucans range from southern Mexico to northern Argentina and Paraguay. Their usual habitat is tropical and subtropical forests and woodlands, and sometimes more open savanna with clumps of trees. Most species occur in lowlands, but some live in higher elevation forests. Toucans are not migratory, although some species may undertake local movements in search of food.

Toucans are relatively large birds, with a body length of 12-24 in (30-61 cm). Their wings are short and rounded, the tail is long and wide, and the legs and feet are stout and strong, with the toes arranged in a zygodactyl pattern (i.e., two facing forward, and two backward).

The most distinctive feature of toucans is their tremendous, seemingly oversized, laterally compressed bill, which in some species is as long as the body. The bill is stout but well-chambered with air-containing cavities, and therefore surprisingly light in weight. The bill curves slightly downward, and often has a serrated inner margin. There is a small hook at the tip of the upper mandible, and the nostrils are placed at the base of the beak, near the head.

The function of the unusually enormous bill of toucans has not been conclusively determined. It may be helpful in plucking fruits that are far away from branches large enough for a toucan to perch on. Alternatively, the large bill may be used to frighten away potential predators, or to intimidate the parents of nestlings or eggs that toucans are predating upon. The bill may also have important social functions, for example, in courtship displays.

A toucan at Lake Arenal, Costa Rica. Photograph by Roy Morsch. Stock Market. Reproduced by permission.

The body plumage of toucans is soft, and usually black or dark green, with conspicuous patches of white, yellow, orange, red, or blue. Toucans have bare, brightly colored skin around the eye. The large bill of toucans is brightly colored in most species, and is likely important in species recognition. The sexes of most species do not differ in size or coloration.

Toucans live in small, harshly noisy, often family related groups. They feed together, with an attentive sentry posted to warn against possible intrusions by predators. Toucans mostly eat fruits, insects, and sometimes the eggs or nestlings of other species of birds. Toucans can manipulate their foods quite dexterously, in spite of their huge bill.

Toucans have a repertoire of harsh croaks, yelps, mews, rattles, and other sounds. Some of the larger species give a series of almost musical renditions at dawn, which may function as territorial songs.

Toucans roost and nest in cavities in trees, commonly using abandoned holes excavated by woodpeckers, although these may be further enlarged by the toucans. During roosting, several birds may crowd into the same cavity, and when doing this they commonly fold their tail up over the back to save space. Toucans lay two to four eggs in an unlined nesting cavity as high up a tree as possible. The eggs are incubated by both parents, who also share the chick-rearing duties, which takes about 40-50 days until fledging occurs.

The largest toucans are those in the genus Ramphastos, which live in lowland, tropical forests. The toco toucan (R. toco) occurs in tropical Amazonian forests, while the chestnut-mandibled toucan (R. swainsonii) occurs from Honduras to Venezuela.

Species of aracari toucans (Pteroglossus spp.) are smaller and relatively gregarious. The green aracari (Pteroglossus viridis) occurs in tropical forests from Venezuela through Brazil.

The toucanets are even smaller. The spot-billed toucanet (Selenidera maculirostris) occurs in forests from Venezuela and Guyana to northern Argentina.

Most species of toucans are less abundant today than they used to be, mostly because of loss of habitat through deforestation. However, the World Conservation Union (IUCN) does not yet list any species as being threatened or endangered.

Resources

Books

Forshaw, Joseph. Encyclopedia of Birds. New York: Academic Press, 1998.

Sick, H. Birds in Brazil: A Natural History. Princeton, NJ: Princeton University Press, 1993.


Bill Freedman

KEY TERMS

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Zygodactyl

—The specific arrangement of toes of certain birds, in which two toes point forward, and two backward. This is the characteristic arrangement in the Piciformes, including the toucans.

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