West Indian Manatee

Trichechus manatus

ManatÍ en Español This page is also available in Spanish.

What weights over 1000 pounds, looks a bit like a walrus with wrinkled, gray-brown, spongy skin, is sometimes called a "sea cow", is related to an elephant, was mistaken for mermaids, can eat more than 100 pounds of vegetables per day, and travels an average of 3 to 5 miles per hour? Why the manatee, of course!

These large animals were once thought to be related to walrus because of the way they look. Today, scientists are able to identify animals using genetics. Now they know that manatees are more closely related to elephants than any other living animal. Scientists believe that manatees evolved from land mammals that returned to an aquatic life.

Manatees are large marine mammals weighing up to 2000 pounds and reaching more than 12 feet in length. Like whales, their large bodies can only be supported in their watery environment. On land, their body weight would crush their internal organs.

Manatees are the only marine mammals that are herbivores. Just to keep their big bodies warm, they have to eat up to one tenth of their body weight every day. For the typical manatee that means more than 100 pounds of water plants! That's equal to more than 200 heads of lettuce!

Warm Water Mammals

Keeping warm is a real problem for these animals. Their cylindrical bodies help conserve heat, but they don't have the blubber that other marine mammals do. Their metabolism is also very low, so they don't generate a lot of body heat. As a result, they can get sick when the water temperature falls below 70° F. In cold water, they can develop pneumonia, get too sluggish to eat, and can die. Most manatees live in warm, tropical waters, but Florida manatees live in sub-tropical waters that get below 70° F in the winter months (Dec. through Mar.). Manatees have a behavior which helps them survive the colder water. In the winter, they seek out the natural warm springs of Florida's coastal rivers. They even gather where electric power plants discharge warm water. To protect manatees, many of these areas are now Manatee Sanctuaries.

manatee range map

Where do manatees live?
This map shows the ranges of the 5 living species of manatees and dugongs.: Florida Manatee (Trichechus manatus latirostris): Southeast coast of United States; Antillean Manatee (Trichechus manatus manatus): Caribbean and coast of Central America; West African Manatee (Trichechus senegalensis): Coast of Western Africa; Amazonian Manatee (Trichechus inunguis): Amazonia; Dugong (Dugong dugon): Indian Ocean - Coasts of Eastern Africa, India, Asia, and Northern Australia

Adaptations

Manatees are well suited to their slow aquatic life. They have flexible front limbs that they use to steer as they swim. They can also use these limbs to hold their food. Their body ends with a large paddle shaped tail. With powerful up and down strokes, they use their tail to push them through the water. Usually they move along at 3 to 5 miles per hour, but when frightened, they can move more quickly.

manatee nose

Member Contributions

Manatee Poetry

Sage Avenue
Echo Horizon

Like all mammals, manatees breathe air. As a marine mammal, they must rise to the surface to take a breath. While resting this happens every 20 minutes, but when they are active, they need to take a breath every 3 to 5 minutes. When people breathe, they only change about 10% of the air in their lungs. When manatees breathe, they change up to 90% of the air in their lungs. To do this, they exhale very hard when their nose breaks the surface, much like a whale or a person snorkeling will do. While they don't "spout" like a whale will sometimes do, there is often a cloud of mist. Breathing like this means there is more fresh oxygen in their lungs, and allows the animal to stay underwater longer between breaths. Manatees also have two other special breathing adaptations. They can only breathe through their nose, and their nostrils have special flaps that close tightly when they dive.

manatee skull A manatee's mouth and teeth are specially adapted to an herbivorous life. They do not have front teeth, only special "marching" molars. Like elephants, they have 4 sets of 6 to 8 molars. As the front molar wears down from chewing on fibrous plants and sand, it is shed. The teeth behind it "march" forward as a new tooth emerges at the back. Without hands, it can be hard to get food to your mouth. To solve this problem, manatees have a large, split upper lip. The left and right sides can move independently to move the food into place. Last of all, behind the lips special ridged pads break food into smaller pieces before the molars finally grind it up.

Reproduction

Manatees are generally solitary animals. However, when a female is ready to mate, several males will gather around her forming a mating herd. After mating, they resume their solitary lives. There is, however, a strong bond between cow and calf. After birth, calves stay close to their mothers, and touching seems to be important to them. They nurse for nearly a year, and stay with their mother for up to two years.

At birth, manatee calves weight 70 pounds (30 kg) and are 50 inches (120 cm) long. They can live to be 70 years old, weigh as much as 2,000 pounds (500 kg), and be more than 12 feet (3 m) long. Reproduction is slow for manatees. Manatees are mature and able to breed at about 10 years of age. The gestation period is one full year for manatees, and cows give birth only once every 3 to 5 years.

Communication

Manatees communicate with each other with voices that sound like clicks and chirps. The sounds they make can be heard by humans. Communication is especially strong between a cow and her calf, and that helps the two remain in contact with each other.

Learn More About Manatees

Manatee Conservation
Profile of Manatee Researcher
WPTI/WCS Manatee Radio Tracking (this link leaves The Wild Ones)
Manatee Encounter
Manatee Meeting
Nose to Nose
Manatee Books