Critter of the Week: Manatee

  • Common name: Manatee (West Indian)
  • Scientific name: Trichechus manatus
  • Type: Mammal
  • Diet: Herbivore
  • Status: Vulnerable
  • Geographic range: migratory (east coast of U.S., Florida, Gulf of Mexico)
  • Size: 8 to 13 feet, 400 to 1,300 pounds
  • Life expectancy: about 40 years, up to 60 years

“He saw three mermaids, which rose well out of the sea; but they are not so beautiful as they were painted, though to some extent they have the form of a human face,” Christopher Columbus records in his journal on January 9th, 1493. 

These “mermaids” are later believed to have been manatees: fully aquatic, herbivorous marine mammals affectionately known as “sea cows.” Really, Columbus? How could anyone mistaken manatees for mermaids? Well, according to Sun-Sentinel’s interview with Anthony Piccolo, a professor of literature at Manhattanville College, resource deprivation on a ship and a curvier standard of female beauty may have been contributing factors.  

The manatee is also associated with the folklore of West Africa. Mami Wata, a water deity also known as “Mother Water,” is often depicted as a mermaid, but sometimes depicted as a manatee. Manatees belong in the order Sirenia, aptly named after the sirens of Greek mythology.

While they may not have melodic voices and flowing hair, manatees are still beautifully unique sea creatures. In addition, manatees are gentle and slow-moving — a significant difference from the dangerous sirens. 

As mammals, manatees must resurface for air about every twenty minutes. They are excellent at breathing, since they can replenish 90 percent of the air in their lungs, according to the encyclopedia Britannica. On the other hand, we replenish about 10 percent of the air in our lungs every time we breathe!  

Manatees never leave the water. They are anatomically interesting, with lungs that are parallel to the water surface and marrow-less, heavy ribs that maintain their horizontal orientation in water. 

Manatees migrate to Florida during the winter, often congregating in the state’s natural freshwater springs in colder weather. They can be spotted as far as Texas and Massachusetts, but this is a rare occurrence because manatees cannot survive in waters colder than 60 degrees Fahrenheit. Despite their large fat stores, manatees don’t do a good job of generating body heat.

You may have noticed that manatees have a larger snout. This is because their upper lip is prehensile, meaning capable of grasping objects. Their upper lip and front flippers allow manatees to eat up to one-tenth of their body weight in 24 hours. Manatees’ diet consists of water grasses, weeds, and other plants, so they also require molar-like teeth and long intestines to properly break down the fibers. Another interesting manatee fact is that their teeth are constantly being replaced by new ones; their teeth grow in from the back and fall out once they’ve worn down at the front of their mouth. 

Despite their slow, relaxed nature, manatees are very intelligent. Apparently they have great long-term memory, exhibit complex associative learning, and can visually discriminate. 

Unsurprisingly, humans are a major threat to manatee populations. We don’t actually know how many manatees there are left; the U.S. Fish and Wildlife Service estimates there are 6,500 West Indian manatees in Florida today. 

Manatees rarely have natural predators. It is estimated that 25 to 35 percent of manatee deaths in Florida come from collisions with watercraft. Manatees’ slow-moving nature, toxic “red tide” algal blooms, discarded fishing equipment, and their low reproduction rate are all factors negatively affecting population sustainability. Manatees are believed to be sexually mature at 5 years, and have one calf about every two years. This makes it difficult for manatees to recover from large population losses, such as the Florida red tide that wiped out 149 manatees in 1996.

Manatees were downgraded from “endangered” to “threatened” status in 2017. Officials deemed that there were significant improvements to habitat conditions and population, but that doesn’t mean we should lessen manatee conservation efforts. Manatees are still protected under the Endangered Species Act, Marine Mammal Protection Act, and Florida Manatee Sanctuary Act. These laws make it illegal to hunt, harass, capture, or kill manatees. 

The manatee has become a symbol for conservation and a beloved animal in recent years. Let’s continue the work in creating site-specific boat speed zones, preserving natural springs, and raising awareness to help the manatees thrive. 

Sources: American Journeys Collection: Journal of the First Voyage of Columbus, Sea Cow ‘Sirens’ Fuel Mermaid Mythology, Encyclopedia Britannica: Manatee, Defenders of Wildlife: Florida Manatee, Save the Manatee, The manatee and the Mami Wata legend, Live Science: Manatees: Facts About Sea Cows, What is Red Tide? 

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