Geoscience Reference
In-Depth Information
cacomistles (similar to ringtails) live in the rainforest and migrate to the deciduous
forest when food is available. These carnivores eat beetles, spiders, scorpions, ants,
termites, grubs, centipedes, eggs, and even land crabs and fruit when available.
They occasionally will take small vertebrates such as mice, lizards, and frogs.
Long-tailed weasels, grisons, skunks, and hog-nosed skunks forage on the
ground. They have dense fur (which is considered valuable) and an extremely
powerful bite that enables them to kill prey larger than themselves. Long-tailed
weasels are common in North America extending into Central and South America
to Bolivia. The grison and tayra occur in Central and South America.
Small cats like the jaguarundi, margay, and ocelot, and the larger puma and
jaguar live in this region or migrate to the forest when prey is plentiful. All occur
from Central America throughout South America; pumas are found north into
Mexico and the United States. Most species are nocturnal.
Birds
Species richness of birds is lower in the dry seasonal forests than the humid rainfor-
est. The total number of bird species found in the seasonal forests of the Neotropics
(635 species) is similar to the number of species found in single sites of lowland
rainforest. Local endemism is high in seasonal forests, surpassing that of the rain-
forest with almost 90 percent of those restricted to these forests endemic. Many
birds are found in only one area of the seasonal forest, and few are found through-
out the entire region. As many as 300 species use the seasonal forest as their pri-
mary habitat year-round. In any single area, about 60-80 species use the forest as
their primary habitat.
Many birds use the forest at the start of the dry season when flowers and fruit
are abundant. Species from higher latitudes in North and South America migrate
to these forests in winter. Many migrating birds, such as warblers, vireos, yellow
throats, flycatchers, and titmice winter exclusively in the dry forests of western
Mexico. At least 109 species of migrating birds have been identified in the Mesoa-
merican subregion.
Puffbirds, motmots, and jacamars are large insectivorous birds endemic to the
Neotropics with several species present in the seasonal forests. Smaller insect
feeders endemic to the Neotropics are species of antbirds, antshrikes, flycatchers,
gnatcatchers, woodpeckers, woodcreepers, wrens, and vireos. These birds exploit
different layers including the ground, understory, and canopy, as well as different
plants or parts of plants (bark, twigs, leaf undersides, and so on). Some species of
antbirds will locate a traveling army ant colony and remain with them for days
until the ants stop temporarily to reproduce. The bird leaves the colony each night
and returns in the morning. Research is currently under way to discover how the
antbird is able to relocate the constantly moving colony each day.
Hummingbirds are restricted to the Americas. They are brightly colored nectar-
feeding birds of many sizes and diverse bill lengths. This allows each species to spe-
cialize on different flowers and nectars. They are found in the seasonal forest
