Abstract
Toucans are one of the most widely dispersed families of neotropical birds, whose range extends from central Mexico to northern Argentina, Paraguay, and Bolivia and from the eastern slope of the Andes to the Atlantic coast. Only in Central America and Colombia do they occur on the Pacific coast.
Toucans are a relatively gregariou group of birds which inhabit the forest canopy whether at sea level or the higher Andean elevations (10,000 feet). They occur in small flocks of up to forty individuals, which move from tree to tree in short, undulating flights. Flying single file, the entire group completely reassembles before embarking for the next tree. Flocks tend to stay in a local area and may be observed on successive days. Only during the breeding season do these flocks break up into individual pairs. which establish nesting territories.
As forest dwellers, toucans rarely visit open savannas and rarely go to the ground, which they will occasionally do co capture prey. Remaining in the trees, toucans there satisfy all their requirements for food, nest sites and security. Their diet consists primarily of a variety of fruits, augmented by some live prey including insects, spiders, small birds, rodents and reptiles. When one bird makes a catch, others may try co snatch the prize away, or at least a piece of it.
Toucans nest in tree cavities, usually the former homes of woodpeckers, which the toucans frequently renovate. Rarely do they do much excavation of noteworthy proportions on their own. A number of oval, white eggs are laid, up to four at a time. Incubation takes approximately sixteen days and young are fledged in six to seven weeks. With the exception of the genus Pteroglossus (the aracaris), toucans roost on limbs at night. The aracaris roost in cavities, with as many as half a dozen birds piled in on top of each other.
Most species of Rampbastids rear only one clutch of young per year in the forest. The aracaris, however, frequently clutch twice and the offspring from the first nest have been observed helping the parents rear the second nest. This helping behavior is unique among Rampbastids, though not in the bird world.
There are approximately forty-three species of Rampbastids grouped into six genera. The large black toucans of the genus Rarnpbastos are, perhaps, the most familiar, and the focus of the popular imagination when thinking of neotropical birds. Such species as the toco and the keelbill inspire the stuff of television commercials and the ariel has been a featured star of the National Wildlife Federation's Ranger Rick magazine.
The smaller toucanets and aracaris, however, are virtually unknown to the general public and even somewhat obscure to the aviculturist , some of whom are initially incredulous that they are of the same family. Lesser known still are the mountain toucans, which occur in the Andes, are rarely seen in groups, and are virtually nonexistant in zoological collections.
The most distinguishing characteristic of the toucan is his large, flamboyantly colored bill. Jn no other group of birds, anywhere in the world, can one find such a cornucopia of colors - such that each species may be readily identified by its beak alone. This gaudy variety bespeaks one theory concerning the purpose of their oversized mandibles: species recognition and sexual display.
Although locally abundant in the forests of the neotropics, toucans may be difficult to observe, especially where they are pursued by Indians for the dinner table or by trappers for the animal trade. ln national parks, on the other hand, where they are protected, toucans can become very tolerant of human activity. At Iguazu Falls National Park in northern Argentina, toco toucans are so familiar with tourists, they may be approached to within a few yards. Red breasted toucans, though less tolerant, may be approached to within one hundred feet. Toucanets and aracaris generally are more easily disturbed and require greater patience to observe.
As the forests of tropical America are cleared for agriculture and other commercial purposes, toucans and their fellow travelers will be squeezed into ever smaller areas. As the trees are felled, fewer nest sites will be available. That is, fewer of the right kind of trees, for toucans nest in the abandoned cavities excavated by woodpeckers, who do their construction in dead or dying trees. There are few dead or dying trees in any given acre of forest. Those that exist usually rot and collapse within a few years creating a continuous housing shortage, especially in a forest being harvested.
From the beginnings of the Maya, Incan, and Aztec civilizations to the arrival of the Spanish conquistadors and beyond to the present day, men of every race, culture, and historical period have admired toucans considering them the personification of neotropical avifauna. Such a noble tradition is warranted indeed! .