The New Neotropical Companion

Toucans, Aracaris, and Toucanets

Perhaps more than any other kind of bird, toucans

(family Ramphastidae) symbolize the American tropics.

With a prominent boat- shaped, colorful bill almost

equal in length to the body, the toucan silhouette is

instantly recognizable. As it flies with neck outstretched,

a toucan appears to follow its own oversize bill (plate 15-

25). To u c a n is derived from tucano, the name used by

Topi Indians in Brazil. Altogether, there are 50 species

in the family Ramphastidae, including toucans, aracaris,

and toucanets, all Neotropical. Currently the taxonomy

of ramphastids is under review, and more species

changes may be designated in the future. Even now,

some toucans are routinely named with not only genus

and species names but also subspecies, as taxonomists

try to decide between lumping or splitting populations.

Be prepared for changes. Toucan anatomy and DNA

indicate a close alliance with woodpeckers (and thus

they are in the same order, Piciformes), and both groups

share certain characteristics of foot anatomy (two toes

face forward, two face to the rear) as well as the habit of

roosting and nesting in tree cavities. Ramphastids occur

in lowland moist forests and montane cloud forests.

Toucans, aracaris, and toucanets range in body length

from 33 to 59 cm (13– 23 in).

Toucans’ seemingly oversize bills are actually

lightweight. The bill is supported by bony fibers

beneath the outer horny surface of keratin (which is not

very different from a fingernail). The upper mandible

is slightly down- curved, terminating in a sharp tip.

Colorful patterns adorn most ramphastid bills; they

may possibly be used for signaling in mate selection.

Recent studies on the Toco Toucan (Ramphastos

toco; plates 15- 26– 27) have demonstrated that the

birds are able to radiate excess heat from their long,

vascularized bills. Their bills thus also function for

thermoregulation. In a paper by Glenn Tattersall and

colleagues, the researchers conclude that the toucan

bill is “relative to its size, one of the largest thermal

windows in the animal kingdom, rivaling elephants’

ears in its ability to radiate body heat.”

Toucan plumage is also colorful, including patches

of green, yellow, red, and white. One major group has

Plate 15- 28. Keel- billed Toucan. Photo by James Adams.

chapter 15 neotropical birds: the bustling crowd 273