Giant otters are the largest
of the river otters and among the most rare and endangered.
There are estimated to be less than 5,000 left in their South
American range. Besides their large size, they are characterized
by the irregular patches of light fur on their chests and
their noisy, gregarious behavior.
Giant otters live in the
rivers, streams, canals and lakes of Brazil, Bolivia, Colombia,
Ecuador, Guyana, northern Argentina, Paraguay, Peru, Suriname,
and Venezuela. The Amazon River and its tributaries, the
Essequibo River in Guyana, the Orinoco River in Venezuela
and Colombia, and the La Plata River between Argentina
and Uruguay are the main river systems that provide habitat
for this amphibious carnivore.
Male giant otters grow to
a length of 1.8 meters long (almost 6 feet) including the
tail, with females being slightly smaller. Fully grown
specimens weigh 22-26 kg (48-70 lbs). Historical reports
from South America show there were once massive otters
reaching 8 feet in length before the species was hunted
to near extinction.
The coat of the giant otter is brown,
but variations include reddish brown to coffee color, and
almost black when wet. The fur is short compared to that
of other otter species, and is very dense, permitting little
or no water to reach the skin. The quality of the fur has
made the giant otter's pelt highly sought after by hunters.
Giant
otters have irregular markings of white to cream-colored
fur on their throat and lower jaw. These markings make
it possible for researchers to identify individual animals.
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| Picture
of giant otter cubs, Pteronura brasiliensis,
3 months old, endangered species, Rupununi River, Guyana |
Image
#: 102784 |
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Kingdom:
Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Carnivora
Suborder: Caniformia/Canoidea
Family: Mustelidae/Mustelids
Genus: Pteronura
Specific: brasiliensis
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The
head of the giant otter is distinctively different from
that of other river otter species. It has a more domed
skull and a profile that is vaguely dog-like, which gives
it the nickname, perro de aqua (water dog). Its neck is
strong and thick. The nose is covered in fur and both the
nostrils and ears can close when the animal is underwater.
It has many long, thick whiskers that help it to detect
moving prey underwater.
Giant otters propel themselves
in the water with their feet, which feature webbing that
extends to the tips of their toes. Their tail, which is
flattened, aids them in swimming and maneuvering in the
water. Hind legs are longer than front legs.
Giant otters
are diurnal and feed on fish, particularly cichlids, characins
and catfish. They also eat freshwater crabs, snakes, amphibians,
caimans and the occasional rodent or bird. They catch prey
with their jaws and eat in the water, unless the prey is
too large, in which case they bring it ashore. They must
eat between 10-20% of their body weight each day.
Adult
giant otters are not generally preyed upon by other animals,
though jaguars, large caimans and anacondas may manage
to capture pups. Their most dangerous predator is man.
Competitors of the giant otter may include large caiman
and possibly river dolphins. The Neotropical Otter (Lontra
longicaudis) shares much of the same territory, but cannot
be called a direct competitor, as they hunt at dusk and
generally prey on smaller fish than do Giant Otters.
Giant
otters are more social than other
species of river otter. They congregate in small family
groups of from 5 to 8 animals (called a "holt")
and establish communal living areas near their feeding
grounds. In their living space, they trample vegetation
and arrange sticks and leaves to their liking. They mark
the space with their anal scent glands, and establish toilet
areas on the edges of their living area to further mark
their territory and dissuade intruders. Dens for sleeping
and raising pups are generally dug in the earth below fallen
logs.
Giant otters sometimes hunt cooperatively, and members
of a holt will usually stay within calling distance of
one another. They groom each other on land and work together
to defend themselves when predators approach or when other
giant otters intrude on their territory.
Giant otters mate
in the water and give birth to 2 or 3 pups in August to
October. The pups stay in their dens for about 3 weeks
and are weaned at 3-4 months. They reach sexual maturity
at 2 years of age. Giant otters in the wild live 10 to
13 years.
Giant otters are known for their unique, loud
vocalizations. Researchers have identified 9 different
sounds, such as barks, snorts, whistles and growls, which
are likely signals or warnings to other members of their
group. The sounds they make are conspicuous to hunters,
which contributes to the decline in their numbers.
Giant
otters are listed as endangered by the IUCN. Their biggest
immediate threat is poaching for their fur, as one giant
otter pelt can bring $250 U.S. Destruction of habitat is
another serious problem, and the number of giant otters
is likely to decrease by 50% for this reason alone by the
year 2025. Currently, giant otters have stable populations
in Suriname, French Guiana and Guyana, as the governments
there have had some success in protecting them.
Alternate
names:
Giant Brazilian Otter, Giant Otter, Loutre Geante
du Bresil, Arirai, Lobito de Cola Ancha, Lobo de Rio, Lobo
de Rio Grande, Lobo del Rio, Lobo Gargantilla, Perro de
Aqua, River Wolf, Water Dog
© Giant otter information
assembled from on-line sources by Kevin
Miller on May 21,
2008 for Seapics.com.
http://en.wikipedia.org/wiki/Giant_otter
http://www.otterjoy.com/otterinfo/pteronura_brasiliensis.html
http://lioncrusher.com/animal.asp?animal=183
http://animaldiversity.ummz.umich.edu/site/accounts/information/Pteronura_brasiliensis.html
http://www2.philadelphiazoo.org/zoo/Meet-Our-Animals/Mammals/Carnivores/Giant-River-Otter.htm
http://www.iucnredlist.org/search/details.php/18711/summ |
