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Manatees: Trichechidae

West Indian Manatee (trichechus Manatus): Species Account



Physical characteristics: Also known as the Florida manatee, the West Indian manatee grows to 13 feet (4 meters) in length, and can weigh up to 3,300 pounds (1,500 kilograms). The nearly hairless skin is gray, and the body has no hind limbs. The tail is wide and paddle-like, and the front limbs each have three to four fingernails. The eyes



West Indian manatees live in shallow water—they must surface for air about every three minutes while they are active. (Douglas Faulkner/Bruce Coleman Inc. Reproduced by permission.)

are small and located on the sides of the head, and though there are only tiny ear openings, the manatee has a keen sense of hearing. The West Indian manatee uses its flexible lips in conjunction with its flippers to get food into its mouth.

Manatees communicate by whistling, chirping, and squeaking.


Geographic range: Found in the eastern coastal waters of the United States, from upper Virginia to the tip of Florida, around the west coast of Florida to Louisiana. Rare sightings have occurred in waters off New York, Texas, and the Bahamas.


Habitat: The West Indian manatee lives in coastal and estuary waters.


Diet: West Indian manatees eat more than sixty species of vegetation including sea grasses, algae, and water hyacinths. They eat between 10 and 15 percent of their body weight every day.


Behavior and reproduction: The basic social unit of the Florida is the female-calf pair, although these manatees do congregate in herds during mating season as well as the winter months, when they migrate to seek refuge in warmer waters.

These polygamous manatees are ready to breed between the ages of two-and-a half and six years, and females give birth every two-and-a-half to three years. Each one-year pregnancy results in the birth of one calf, though twins make up 1 to 2 percent of all births. Mothers nurse, feed with mother's milk, their young. The West Indian manatee can live for more than fifty years.

The manatee has no major predator. Death is usually caused by human activity.


West Indian manatees and people: The West Indian manatee has been hunted as a source of meat, fat, oil, bone, and hide, though it is now protected under law. Those laws, however, are difficult to enforce. The U.S. Fish and Wildlife Service estimates that 25 percent of all Florida manatee deaths are due to boating accidents.


Conservation status: The West Indian manatee is Endangered according to the IUCN, and is protected throughout its range. It is not known how many are illegally hunted for food each year. The primary reason for the decimation of the population is human activity, including pollution, habitat destruction, and recreational boating and fishing.

According to Boat/US Magazine, 2003 proved one of the most deadly years for the West Indian manatee. A record 380 manatees were killed that year. Ninety-eight of those deaths were the result of red tide. Red tide is a naturally occurring phenomena that happens when a type of phytoplankton, microscopic plants, produces chemical toxins, or poisons. These toxins are then released into the water, killing thousands of fish, dolphins, manatees, and other marine life.

Seventy-three Florida manatees died from boating accidents in 2003, the lowest total since 1997. The most recent surveys indicate that the Florida manatee population is over three thousand, a significant increase from six hundred recorded in 1974. ∎

FOR MORE INFORMATION

Books:

Faulkner, Douglas. Of Manatees and Man. Philadelphia: Xlibris Corp., 2000.

Foott, Jeff, and Barbara Sleeper. In the Company of Manatees: A Tribute. New York: Three Rivers Press, 2000.

Periodicals:

Bryner, Jeanna. "Brrr … Manatees Catch Cold." Science World (January 12, 2004): 4–5.

Kalvin, Jim. "Weighing In On the Manatee Debate." Boat/US Magazine (September 2002). Online at http://articles.findarticles.com/p/articles/mi_m0BQK/is_5_7/ai_91085603 (accessed on July 9, 2004).

"Manatee Deaths Up, Boat Toll Down." Boat/US Magazine (March 2004). Online at http://articles.findarticles.com/p/articles/mi_m0BQK/is_2_9/ai_114604599 (accessed on July 9, 2004).

Web sites:

Bayan-Gagelonia, Ruby. "The Florida Manatee." Ecofloridamag.com http://www.ecofloridamag.com/archived/manatees.htm (accessed on July 9, 2004).

Manatee Junction. http://www.manateejunction.org/ (accessed on July 9, 2004).

"Manatees." Defenders of Wildlife. http://www.defenders.org/wildlife/new/manatees.html (accessed on July 9, 2004).

Wonderful World of the Manatee. http://www.manateeworld.net/index.php (accessed on July 9, 2004).

Additional topics

Animal Life ResourceMammalsManatees: Trichechidae - Physical Characteristics, Behavior And Reproduction, West Indian Manatee (trichechus Manatus): Species Account - GEOGRAPHIC RANGE, HABITAT, DIET, MANATEES AND PEOPLE, CONSERVATION STATUS