The manatee is a large and gentle mammal that lives in coastal waters and rivers of the southeastern United States, the Caribbean, eastern Mexico, Central America and northern South America. Though bulky, the sea cow, as it's often called, is a graceful swimmer that moves along the water at about 5 miles an hour. Barring misfortune, the manatee can expect to live 40 to 50 years.
Breeding and Reproduction
The female manatee or cow is not sexually mature until she is about 5 years of age, and she only breeds every three to five years. She doesn't form a permanent bond with a male manatee, but instead is followed by a mating herd of approximately a dozen or more male manatees, or bulls. Breeding and birth can happen at any time during the year, but most births occur during the spring and summer. The gestation period is about one year.
Rarely is more than one calf born at a time, although there have been incidences of manatee twins. The mother will seek a quiet area to give birth; the calf is born either head or tail first. Once born, the calf vocalizes and the mother-child bonding begins for about two years. A newborn calf weighs 60 to 70 pounds and is three to four feet in length. The female manatee nurses for one to two years, although the calf is nutritionally capable of providing for himself by his first birthday.
Manatees often travel alone, in pairs or in small groups. They never leave the water but must breathe air at the surface. They migrate to warmer waters during seasonal changes because they are unable to sustain water temperatures below 63 degrees Fahrenheit and prefer temperatures above 72 degrees. Manatees have slow metabolisms, and cold water can drain their body heat. Creatures of habit, they usually congregate in natural springs, near power plants, canals and basins during colder weather and return to the same spots each year.
Human encroachment is directly related to manatee deaths, along with predators and natural circumstances. Because they are slow moving and often found in coastal waters, watercraft hulls and propellers can strike a manatee, causing its death. Entanglement of fishing lines, nets and hooks are also a danger for the manatee. The predators of young manatees are crocodiles, sharks and alligators. Natural circumstances include cold stress, pneumonia, red tide and gastrointestinal disease. The manatee is an endangered species: it's illegal to hunt them in the United States.
Pauline Gill is a retired teacher with more than 25 years of experience teaching English to high school students. She holds a bachelor's degree in language arts and a Master of Education degree. Gill is also an award-winning fiction author.