When Christopher Columbus first saw a West Indian manatee, he thought it was a mermaid – you can decide for yourself if the comparison is apt.
November is Manatee Awareness Month in Florida, so this week we’re checking in with the charismatic sea cows – and if you tweet us what makes the manatee’s teeth unique among mammals, you could win a prize.
The West Indian manatee is found in two distinct populations in the Caribbean and Florida, where they live in warm, shallow water, migrating somewhat with the seasons. They are tolerant of a range of saltiness, although they need occasional access to freshwater to keep from being dehydrated.
Manatees are about 10 feet long and can live to be about 50 years old. Despite their massive size, they are surprisingly agile, even though they swim and steer with just their tails. They are usually pale grey, although calves are darker. Their skin is constantly flaking off, likely to reduce algae. For the most part, manatees live alone, spending about six to eight hours a day eating.
Eating takes up so much of their day because their diet consists primarily of seagrass, which has a very low caloric value. Although manatees have developed a low metabolic rate to help conserve energy, they still need to eat a lot of seagrass – about 10-15% of their body weight each day (!) In addition to seagrass, manatees use their flippers to dig up roots, and will occasionally eat invertebrates or fish.
Manatee eyesight is not very powerful, so they rely on sensitive bristles on their lips to find food. They may also be able to detect pressure changes through their hair, and mothers and calves are known to communicate using squeaks and grunts, and may remain in communication after the calf has left its mother, at the age of about two.
Because they have no natural predators, manatees don’t have highly developed escape methods. For centuries, people hunted manatees, although never commercially, and by the 18th century, the English were concerned enough about the manatee population to make Florida a sanctuary for them.
Florida’s state law banning killing manatees has been on the books since 1893, although illegal poaching is still an issue. The manatee population has been growing slowly, and there are now about 3,000 in Florida waters, though they remain classified as endangered.
Boat strikes pose a significant threat to manatees; other threats to manatees include habitat loss and deterioration, particularly the decline of seagrasses; entanglement in fishing gear or debris; and the effects of hurricanes and “red tides.”
There’s good news for these animals, though -- Florida is actively campaigning to reduce collisions with boats, protect manatee habitat, and raise awareness, including naming the manatee Florida’s official marine mammal.
You can learn more about manatees from Oceana’s marine wildlife encyclopedia.