West Indian Manatee Facts:
Description:
West Indian manatees are large, gray aquatic mammals with bodies
that taper to a flat, paddle-shaped tail. They have two forelimbs, called
flippers, with three to four nails. Their head and face are wrinkled with
whiskers on the snout. The manatee's closest land relatives are the elephant
and the hyrax, a small, gopher-sized mammal. Manatees are believed to have
evolved from a wading, plant-eating animal. The West Indian manatee is
related to the West African manatee, the Amazonian manatee, the dugong, and
to the Steller's sea cow, which was hunted to extinction in 1768. The
average adult manatee is about 9.8 feet ( long and weighs between 800-1,200 pounds (362-544 kilograms).
Habitat and
Range: Manatees can be found in shallow,
slow-moving rivers, estuaries, saltwater bays, canals and coastal areas.
Manatees are a migratory species. Within the United States, West Indian
manatees are concentrated in Florida in the winter, but they can be found in
summer months as far west as Texas and as far north as Virginia. However,
these sightings are rare. Summer sightings in Alabama, Georgia and South
Carolina are common. West Indian manatees can also be found in the coastal
and inland waterways of Central America and along the northern coast of
South America, although distribution in these areas may be spotty.
Behavior Manatees
are gentle and slow-moving. Most of their time is spent eating, resting, and
in travel. Manatees are completely herbivorous. They eat aquatic plants and
can consume 10-15% of their body weight daily in vegetation. They graze for
food along water bottoms and on the surface. They may rest submerged at the
bottom or just below the surface, coming up to breathe on the average of
every three to five minutes. When manatees are using a great deal of energy,
they may surface to breathe as often as every 30 seconds. When resting,
manatees have been known to stay submerged for up to 20 minutes.
Lifespan,
Mortality, Population: West Indian manatees have
no natural enemies, and it is believed they can live 60 years or more. Many
manatee mortalities are human-related. Most human-related manatee
mortalities occur from collisions with watercraft. Other causes of
human-related manatee mortalities include being crushed and/or drowned in
canal locks and flood control structures; ingestion of fish hooks, litter
and monofilament line; entanglement in crab trap lines; and vandalism.
Ultimately, however, loss of habitat is the most serious threat facing
manatees today. There are approximately 3,000 West Indian manatees left in
the United States.
Breeding and Reproduction: The reproductive rate for manatees is slow. Female manatees are not sexually mature until about five years of age, and males are mature at approximately nine years of age. On average, one calf is born every two to five years, and twins are rare. The gestation period is about a year. Mothers nurse their young for one to two years, so a calf may remain dependent on its mother during that time.
