Manatees are sometimes called sea cows. Even though they are huge mammals they are very graceful swimmers in coastal waterways and rivers. Powering themselves in the water with their strong tails, manatees typically glide along at 5 miles an hour but can swim up to 15 miles an hour in short spurts. The manatee's closest relatives are the elephant and the hyrax. The West Indian manatee is related to the West African manatee, the Amazonian manatee, the dugong, and Steller's sea cow, which was hunted to its extinction in 1768. The average adult manatee is about 10 feet long and can weigh between 800 and 1,200 pounds.
Manatees can be found in shallow, slow-moving rivers, estuaries, saltwater bays, canals, and coastal areas — mainly where seagrass beds are found or freshwater vegetation grows. There are three species of manatees, classified by where they live. One manatee population ranges along the North American east coast from Florida to Brazil. Other species inhabit the Amazon River and along the west coast and rivers of Africa.
Manatees are born underwater. The mother manatees must help their calves to the surface so that they can take their first breath, but the infants can usually swim by themselves in about an hour. Manatees often swim alone or in pairs. They are not a territorial animal, so they have no need for a leader or for others to follow. When manatees are seen in a group, it is because they are mating or sharing a warm area that has a large food supply. A group of manatees is called an aggregation. An aggregation usually never grows larger than about six individuals.
Manatees are herbivores. While in the ocean, they tend to favor sea grasses. When they live in rivers, they munch on freshwater foliage. Manatees will also eat algae. According to experts, a manatee can eat a tenth of its own weight in 24 hours. That can equal up to 130 lbs.
During mating season, a female manatee, which is called a cow, will be followed around by a dozen or more males, which are called bulls. The group of bulls is called a mating herd. The bull takes no part in the raising of the young.
A female manatee is pregnant for about 12 months. The calf, or baby manatee, is born underwater. In five years, the young manatee will be sexually mature and ready to have its own young. Manatees usually live for about 40 years.