Sloth Versus Manatee
Do sloths and manatees have anything in common? One is a slow-moving arboreal mammal, and the other is a lumbering aquatic creature, so it’s hard to see the similarities at first. But let’s take a closer look and compare these two lovable, oddball animals. You’ll be surprised by a unique feature they share!
What are manatees?
Manatees are large, herbivorous aquatic mammals that are found in shallow, warm waters in rivers, natural springs, estuaries, and coastal areas. They are also known as “sea cows” due to their grazing habits, slow movements, and gentle nature. Manatees have rounded bodies with thick, wrinkled skin and paddle-like flippers. They never leave the water but, like all marine mammals, they must breathe air at the surface.
There are three species of manatee: African manatee (Trichechus senegalensis), Amazonian manatee (T. inunguis), and West Indian manatee (T. manatus). The West Indian Manatee has two subspecies, the Florida manatee (T. manatus latirostris), which is endemic to the southern United States, and the Antillean manatee (T. manatus manatus) in the Caribbean. All manatees belong to the order Sirenia, a word that comes from sirens of Greek mythology. This name comes from a legend involving sailors confusing these animals with mermaids.
Are sloths and manatees related?
Both animals are mammals, sloths belong to the superorder Xenarthra, while manatees belong to the superorder Afrotheria, which also includes elephants. However, both of these superorders belong to the clade Atlantogenata. The two orders are thought to have diverged from each other around 90 million years ago!
Where do they live?
All sloths are found in the rainforests of Central and South America. The West Indian manatee ranges along the North American east coast from Florida to Brazil. The Amazonian manatee species inhabit the Amazon River and the African manatee swims along the west coast and rivers of Africa.
Unique necks
All mammals have seven cervical vertebrae in their necks, with a few exceptions: Three-fingered sloths have nine, and two-fingered sloths have six, as well as the manatees! This difference in the number of vertebrae is thought to be related to differences in the animals’ neck flexibility and feeding habits.
Manatees, sloths, and water
Despite their size, manatees are graceful swimmers in coastal waters and rivers. Powering themselves with their strong tails, manatees typically glide along at 5 miles an hour but can swim 15 miles an hour in short bursts.
Manatees never leave the water but, like all marine mammals, they must breathe air at the surface. A resting manatee can remain submerged for up to 15 minutes, but while swimming, it must surface every three or four minutes.
Sloths live on the canopy of trees but sometimes they can be seen swimming in rivers, lagoons, or mangrove waters, maybe with less elegance than manatees, but at least they are faster on the water than outside. Unlike manatees, sloths don’t submerge under water.
Manatees and Giant Sloths
Although these animals are not related at all, manatees make us think of the extinct aquatic sloths of the past from the genus Thalassocnus. Just like the modern ‘sea cows’, these giant sloths developed similar specialized features for the life on the water.
The only records we have of these aquatic sloths are mere fossils, and all the images of them are illustrations from paleoartists, but it’s easy to imagine the Thalassocnus swimming around like manatees when you these pictures! (And, interestingly enough, there was also a giant, extinct Sirenian: the Steller’s Sea Cow [Hydrodamalis gigas].)
Tree leaves and Seagrass
Modern tree sloths are folivores, which means they primarily eat leaves. In contrast, manatees are herbivores that graze on sea grasses, algae, and other aquatic plants. They have large, muscular lips that they use to graze on the vegetation, and they can consume up to 10-15% of their body weight in food each day.
Giant aquatic sloths were also herbivorous but fed on aquatic vegetation such as water lilies, leaves, and stems of aquatic plants. They would have had to spend most of their time in the water to find enough food, and their teeth were adapted to grazing on tough vegetation.
Threats manatees and sloths face
All three species of manatees are listed as vulnerable to extinction by the IUCN. The main threats these gentle animals are facing are habitat loss, urban development, changing temperatures, water quality, and boat strikes. However, since 2017, the US Fish and Wildlife Service doesn’t consider manatees in Florida endangered anymore, degrading their status from endangered to threatened. This caused a lot of controversy as conservationists claim this new status is detrimental to their conservation efforts.
Except for maned and pygmy sloths, the other four sloth species are considered as ‘Least Concern´. However, the authorities in Costa Rica are considering sloths as threatened animals, due to habitat loss and the alarming rate sloths are admitted to rescue centers daily. We at SloCo are launching soon The Great Sloth Census, a project where we’ll study sloth populations and population trends in Costa Rica.
How can we help sloths and manatees?
A great way to help manatees is by supporting organizations working in conservation, such as Save The Manatee Club.
Other simple actions we can do is reduce our carbon footprint and plastic use. If you live in an area close to manatees, you can provide reports whenever you spot a manatee to help researchers monitor manatees. Contacting authorities and policymakers to ask them for more protection is a great way of deep involvement in the cause.
In the end, no matter the species, we all should practice these actions to save wildlife around the world!
-Cecilia Pamich
Communications & Outreach
