In the tiny
tropical nation of Costa Rica, there are 850 species of
birds alone -- or about 1/10 of all known birds in the
world! With such a large number of avian species in one
country, all of the birds of Costa Rica have developed
specialized adaptations to take advantage of every available
opportunity. Many of these adaptations involve beaks -- the
unique size and shape of a birds beak directly correlates to
its specialized use.
The Scarlet Macaw
One of the
jewels of the Costa Rican rainforest is the scarlet macaw.
There is hardly a more beautiful sight to be seen than a
group of macaws flying past at up to 35 miles per hour.
These beautiful birds use their strong beaks to feed on the
toughest fruits and nuts that other rainforest species
cannot open.
Occasionally, scarlet macaws are seen consuming clay found
along riverbanks. Scientists now think that the clay may
help the birds to digest harsh chemicals such as tannins
that are ingested when they eat unripe fruit.
Scarlet macaws,
like many birds, form a close monogamous pair bond for
life. The pair are dutiful parents, both male and female
help to care for the chicks once they hatch. The young
macaws remain with their parents for about two years, until
they are mature enough to fledge, or set out on their own.
Only when the young macaws fledge will their parents then
raise another group of chicks.
Unfortunately,
scarlet macaws are threatened by loss of habitat and by the
illegal pet trade. In fact, macaws draw huge sums from
traders -- an individual bird may be sold for up to $1000.
Toucans
Toucans are
visually distinct birds that can be found throughout the
tropics of Central America. Different species of toucans can
be distinguished based on beak size, body size, and body
coloration. The behavior of the species in the toucan
family, on the other hand, is very similar.
The function of
the unique bill of toucans is not fully understood, but it
is suspected that it allows the bird to pluck fruit from
branches that cannot hold its weight. The strong beak is
also used in “bill clashes” when defending a tree. A great
deal of the diet consists of fruit that can be taken in by
the tipping back of the head and a gulp. Toucans are not
entirely frugivores. They also prey upon birds, snakes,
insects, frogs, and lizards that provide a good protein
source.
Threats to the toucan include hunting for meat and capture
for the pet trade.
Hummingbirds
One of the most
dynamic groups of birds in Costa Rica are the hummingbirds.
These tiny birds beat their wings at 100 beats per second,
moving their wings so rapidly that the human eye cannot
detect them moving at all. The rapidly-moving wings of the
hummingbird do indeed make a humming sound, which has earned
the birds their name.
Hummingbirds are
the smallest birds in the Costa Rican jungle, their eggs are
no larger than coffee beans and their nests may only be the
size of a thimble. But, it takes a lot of energy for
hummingbirds to fly. In fact, these tiny birds have the
highest metabolic rate per unit of body weight in avian
world. To maintain this energetically-expensive lifestyle,
hummingbirds consume up to 850% of their own weight in food
and water each day.
Hummingbirds
feed on nectar from flowers using their extremely long
tongues. In the Costa Rican rainforest, hummingbirds have
bill shapes that are perfectly adapted to feeding on various
forest flowers. This is an example of a mutualistic
relationship, for while the birds get food, the plants get
pollinated as the bird rubs against them. The specialized
predation by hummingbirds on certain flower species that fit
their special bill shape ensures specialized pollination for
the patchily-distributed flowers. Thus, this ingenious
relationship ensures that the hummingbirds pollinate the
correct flowers.