Pink River Dolphin
Inia Geoffrensis
The amazon river dolphins or botos are born grey and become pinker
with age. This is because, as the dolphin grows older, its skin becomes
more translucent allowing the blood to show through. When excited, they
will flush to a bright pink temporarily, like your face might when you
get embarrassed or excited. They have a long powerful beak, small eyes
and are slow swimmers. They also have small hairs on their snout which
may help them find foot from the muddy river bottom. They can reach
up to ten feet long and two hundred pounds. They are unique among dolphins
for having molar-like teeth and can chew their prey. They are quite
solitary animals, and are found in the main rivers of the Amazon and
Orinoco river systems of tropical South America.
Pink River Dolphins inhabit muddy stagnant water, and during flooding
will move onto the flooded forests leaving them at risk of stranding.
They are however extremely flexible so they can weave through the obstacles
of trees as they search for their prey. They are a completely freshwater
species, never venturing into salt water. Because Amazon River dolphins
do not have any known natural predators -- other than humans -- they
do not need to live in large protective groups called pods. Pink dolphins
hunt alone during the high water season when their prey disperse into
the floodplains. At other times, they are found in small family groups
of 5-8 animals which seem to be led by a dominant adult male. At river
confluences, as many as 35 pink dolphins work together to catch their
prey. They feed on crustaceans, crabs, catfish, and small fresh water
fish. A unique characteristic of the pink river dolphin is the unfused
vertebrae in its neck, which allows for the 180-degree head turn, giving
them greater flexibility in floodplain forests, grassland, tributaries
and shallow waters. Another added hunting benefit is their excellent
eyesight which they use to locate prey in clear water. In murky water
they emit a series of clicking noises, 30 to 80 per second, which they
then use as sonar by listening for them to bounce off of potential prey.
They give screeching alarm calls to warn other dolphins of predators.
Of the five freshwater species of dolphins in the world, the pink Amazon
River dolphin also known as botos, are considered to be the most intelligent.
These friendly, sensitive, mammals have a brain capacity 40% larger
than that of humans. They have lived in harmony with the people of the
Amazon and its tributaries for centuries, but now face extinction in
some areas. Twenty years ago the pink river dolphin was considered to
be one of the least threatened species of dolphins, but now they have
become one of the most endangered species due to human interference.
The accelerated and commercialized destruction of the Amazon Rainforest
has contributed to threatened survival of the pink river dolphin. The
Amazon River Dolphin is currently threatened by habitat destruction,
hydroelectric dam projects, mercury poisoning from gold prospecting,
accidental entangling in fishing nets, pollution, and boat traffic.