Also known as sea cows, manatees are large, plant-eating marine mammals. Though not related to cows, manatees are similar in that they are slow and gentle and spend much of their time grazing on vegetation.
The West Indian manatee is the largest of three species of manatee. There are two subspecies of West Indian manatee: the Florida manatee and the Antillean manatee.
Averaging about 3 m (9-10 ft.) long, West Indian manatees can be as large as 4 m (13 ft.). They typically weigh about 450 kg (1000 lb.) but can be as heavy as 1600 kg (3500 lb.).
West Indian manatees live in the coastal waters, including rivers and estuaries, of southeastern United States, Central and South America, and the Caribbean. They can be found in both saltwater and freshwater environments, but they need access to freshwater to drink.
West Indian manatees are grayish-brown. They have two flippers and a paddle-shaped tail. Their face and body have sensitive hairs, known as vibrissae, which help them forage for food, detect water currents, and navigate through murky water.
How Manatees Stay Warm
Although manatees are large, they do not have enough body fat to insulate themselves from cold waters. In fact, their large body is made up mostly of their stomach and intestines.
Any water below 20°C (68°F) can be deadly for manatees. As such, in the winter, they migrate to areas where the water is warm, relying on natural springs, power plant wastewater discharge, and thermal basins.
How Manatees Swim
Manatees propel themselves through the water with their tails. They control their buoyancy with their large lungs and special diaphragms.
Though generally slow creatures, moving at speeds under 8 km/h (5 mph), manatees can swim as fast as 24 km/h (15 mph) in short spurts. They are agile in the water, with the ability to roll, do somersaults, and swim upside down.
Manatee Necks
One thing manatees cannot do is move their heads sideways. In order for them to look at something behind them, they need to turn their entire bodies.
This is because manatees only have six neck vertebrae. Most mammals (with the other exception being tree sloths) have seven neck vertebrae.
How Manatees Breathe
Most mammals have one diaphragm, the muscle that helps inflate the lungs. But manatees have two hemidiaphragms.
This allows them to replace 90% of the air in their lungs when they breathe. As a comparison, humans only replace 15% of the air in their lungs when they breathe.
Manatees can hold their breath for as long as 20 minutes but typically come up to the surface to breathe every three to five minutes.
What Manatees Eat
West Indian manatees eat seagrasses, mangrove leaves, algae, and other aquatic plants. They spend eight hours a day eating, consuming up to 10% of their body weight each day.
To keep up with the wear and tear of grazing, manatee teeth are continually replaced. Sort of like a tooth conveyor belt, new teeth grow in at the back of their mouth. Those teeth then slowly move to the front of their mouth, and from there, they fall out.
Social Structure
Manatees are generally solitary animals, but they come together in warm water sites during the winter and to form breeding herds. They are gentle animals and rarely fight.
They communicate vocally with squeaks and screeches. Manatees may also learn information about one another in a grosser way: by eating one another’s poop! It is thought that a manatee can learn about the breeding status or dominance of other manatees from their poop.
Manatee Reproduction
After 13 months, female manatees give birth to one baby, called a calf. A newborn manatee is about 1.2-1.4 m (4-4.5 ft.) long and weighs about 27-32 kg (60-70 lb.).
Mother manatees nurse their babies with teats located just behind their flippers. After a few weeks, calves can start eating plants as well. They stay with their mother for two years and learn how to find food, shelter, and warm water habitats.
Conservation Status
West Indian manatees have no natural predators, though baby manatees are sometimes preyed upon by coastal sharks. In the wild, they can live up to 60 years, but their average life span is about 30 years.
They face threats such as boat collisions, seagrass die-off, loss of warm water habitat, entanglements in fishing gear, and entrapment due to high water events, cold snaps, and red tides. As such, the West Indian manatee is classified by the IUCN as vulnerable.
What You Can Do to Help
If you would like to help West Indian manatees, one important thing you can do is give them space. Do not get too close to manatees you see in the wild.
If you are in a boat, slow down! Manatees are slow-moving and cannot move out of the way of fast-moving boats. Many manatees die or are seriously injured as a result of boat collisions.
West Indian Manatee Range
West Indian manatees live in the coastal waters, including rivers and estuaries, of southeastern United States, Central and South America, and the Caribbean.
More Manatee Resources
- “10 Things You Didn’t Know About Florida Manatees.” Everglades Foundation.
- Florida Fish & Wildlife’s Manatee Page
- Oceana’s West Indian Manatee Page
- Frost, Emily. “14 Fun Facts About Manatees.” Smithsonian Magazine. March 31, 2014.
- “A First for Mammals: Manatees Use Hairs as ‘Underwater Antennas’.” University of Florida News.
- Bauer, Gordon B., Debborah E. Colbert, Joseph C. Gaspard III. “Learning About Manatees: A Collaborative Program between New College of Florida and Mote Marine Laboratory to Conduct Laboratory Research for Manatee Conservation.” January 2010. International Journal of Comparative Psychology. 23(4):811-825.
- “Protecting Manatees.” National Wildlife Federation.
Quick Fact Sheet
Common Name(s): West Indian Manatee
Scientific Name: Trichechus manatus
Animal Type: mammal
Size: 3 m (9-10 ft.) long
Weight: 450 kg (1000 lb.)
Lifespan: Up to 60 years
Conservation Status: Vulnerable
About the Author
Abi Cushman is a contributing editor of Animal Fact Guide and My House Rabbit. She is also an award-winning author and illustrator of funny picture books for kids, including Wombats Are Pretty Weird and Flamingos Are Pretty Funky.
To learn more and to download free activity sheets, visit AbiCushman.com.
