El Yunque Fact
Sheet
How much does it
rain in the rain forest?
That depends on which part of the forest you are in. Generally speaking,
the higher you are in the forest, the more it will rain. Maximum amounts
occurring at the forest’s highest elevations have reached over
250 inches (635 centimeters) annually, while lower elevations receive
only 50-60 inches (120-150 centimeters).
Where does
all the water come from?
It comes from rainfall much of which is brought to us by the Trade Winds.
The Trade Winds, with their moisture laden air sweep eastward across
the Atlantic ocean and Caribbean sea from Africa. These constant wind
currents were named the Trade Winds because they filled the sails of
ships sailing from Europe and Africa that carried trade goods to and
from the new world. When the Trade Wind clouds reach mountain ranges
like those in the Caribbean National Forest, they are driven upward
along the slopes. As the moisture laden air rises it becomes colder
and condenses into raindrops which fall on the forest below. This phenomenon
is known as “orographic” rainfall and it produces much of
the rain the forest receives each year. It is estimated that the forest’s
average rainfall (120 inches-304 centimeters/year) would yield 160 billion
gallons (605 billion liters) annually, enough to supply the municipality
of San Juan with a population of half a million people for over two
years!
Are there any snakes
in the Caribbean National Forest?
Yes, there are 5 or 6 species of snakes that live in the forest. They
are rarely seen, are non-poisonous and pose no threat to humans. The
largest of these is the Puerto Rican Boa which can reach a length of
6 feet. It is a tree climbing predator, hunting at night for small animals
and bird eggs. It can sometimes be seen at lower elevations coiled-up
and sleeping during the day. The other snake species found in the forest
are much smaller and do not climb trees and so are much harder to find.
Is there any gold
left in the rivers of the Caribbean National Forest?
Yes, but don’t expect to become wealthy by searching for it; estimates
vary, but at most you could expect to collect no more than US$2.00 worth
for a full day’s hard work! In the early days gold was removed
from the sands of rivers such as the Río Mameyes which parallels
PR 191 on the way to the Caribbean National Forest, but the source of
the gold was never discovered and the work was eventually discontinued.
Why are there no
large animals in the Caribbean National Forest?
The island of Puerto Rico was formed by volcanic activity during the
Triassic period. Thrusting out of the Caribbean sea it had no land bridge
to any continent. Consequently, the animals of Puerto Rico (and the
Caribbean National Forest) originally arrived on the island by either
swimming, floating or flying, and thus were smaller in size than those
found on large continents. The largest mammalian animals in the forest
are the rats, bats and the mongoose. A reptile, the Puerto Rican Boa
can grow to a length of 6 feet but poses no threat to humans. None of
the animals of the forest, large or small (including insects) are poisonous.
The tarantulas, scorpions and centipedes found in the forest can provide
a venomous bite (similar to a bee sting) but are only dangerous to those
who are allergic!
I have heard that
it “rains frogs” in the Caribbean National Forest. Is this
true?
This interesting forest legend involving Puerto Rico’s indigenous
and beloved Coquí frog Eleutherodactylus coquí is actually
based on scientific fact! During those times of the year when the humidity
is high, the tiny Coquí frogs will climb to the forest canopy,
sometimes as high as 100 feet (30 meters). Predators such as the Tarantula
anticipating this behavior, lay in wait for the frogs. Many frogs are
caught by the predators during their ascent. Instead of returning to
the ground by the same dangerous path, the surviving frogs prefer to
launch themselves into the air, thus bypassing their predators on the
way down. The tiny frogs are almost weightless so that they float to
the forest floor unharmed. If you are lucky enough to be sitting under
a tree when this is happening, you will indeed be “rained upon”
by tiny frogs!
Why is the Puerto
Rican Parrot almost extinct?
The Puerto Rican Parrot Amazona vittata is the only native parrot on
the island. When Christopher Columbus arrived here on his second voyage
of exploration in 1493, these birds were a common sight throughout the
island. This parrot is a forest bird which requires large hollow tree
trunks for nesting. As trees were cut-down by the original settlers
to make way for farms, the parrots gradually retreated into the remaining
patches of forest. During the ensuing centuries it is estimated that
85% of the island was deforested. Only in the protected Caribbean National
Forest could the parrots still find the large trees that they needed
for nesting. Until laws were enforced that stopped parrot hunting in
the forest the parrot population decreased substantially. In 1968 the
Puerto Rican Parrot was placed on the Federal Endangered Species List
and cooperative effort by the USDA Forest Service, the US Fish and Wildlife
Service, the Commonwealth of Puerto Rico Department of Natural and Environmental
Resources and the World Wildlife Fund were begun to recover this important
species. The continuing decline in the parrot population is results
from a number of factors; nest competition by the Pearly-eyed Thrasher,
an aggressive bird that has invaded the parrot’s prime habitat;
an infusion of honeybees that have taken over cavities in many of the
Palo Colorado trees suitable for parrot nesting, and for various other
reasons.
A parrot aviary has been established in
the Caribbean National Forest. Here parrot eggs are hatched and fledged
in captivity, birds are prepared for living in the wild and subsequently
released. The present population in the wild numbers less than 50 individual
birds but captive individuals and pairs are being released into the
wild on a yearly basis, and their survival rates are encouraging.
