Toucans are
members of the Neotropical near passerine bird family Ramphastidae.
The Ramphastidae are most closely related to the American barbets. They
are brightly marked and have large, often colorful bills. The family
includes five genera and over forty different species.
Toucans
nest in cavities in trees, and the presence of suitable trees is a habitat
prerequisite for toucans. For the
most part toucans don't excavate
nesting cavities, although some green toucanets
do.
Toucans
are arboreal and typically lay 2–21 white eggs in their
nests. They make their nests in tree hollows and holes excavated by
other animals such as woodpeckers. The toucan bill has very limited use as
an excavation tool. When the eggs hatch, the young emerge completely naked,
without any down. Toucans are
resident breeders and do not migrate. Toucans
are usually found in pairs or small flocks. They sometimes fence with their
bills and wrestle, which scientists hypothesize they do to establish dominance
hierarchies.
The legs of the toucan are strong and rather short.
Their toes are arranged in pairs with the first and fourth toes turned
backward. The colorful and large bill, which in some large species
measures more than half the length of the body, is the hallmark of toucans. Despite its size, the toucan's
bill is very light, being composed of bone struts filled with spongy
tissue of keratin between them.