What is a Sloth?
A sloth is an arboreal mammal indigenous to the South American Rainforests. The name has come to suggest laziness or slowness, is rooted in easy, slow-moving lifestyle of sloths. The sloth is very slow and deliberate in its movements, living upside down in rainforest trees for most of its life. Its digestive system is likewise slow. A traditional meal of leaves may take as much as a month to completely digest.
The modern sloth is relatively small in size. Most are approximately two feet (.61 m) long. They may weigh approximately nine pounds (roughly four kg). They have small eyes and ears, and only some varieties have tails. Their brown or grey coats are fuller toward the head and upper body, and they have an undercoat of dense fur. Average life expectancy in the wild ranges between 10-20 years, while the sloth in captivity may live up to 40 years.
The sloth’s prehistoric ancestor is the Giant Ground Sloth, Megatherium, which may have been as large as the modern elephant. Unlike modern sloths, the Ground Sloth was not arboreal, and its size made it virtually invulnerable to predators. Past studies suggest the saber-toothed tiger might have preyed on the giant sloth, but most scientists now dismiss this suggestion. The sloth was simply too large, and could counter an attack viciously if necessary.
Like its prehistoric ancestors, today’s sloths are mostly herbivores. They occasionally eat small insects and lizards, but in general their digestive system is ideally suited to consuming leaves from rainforest trees. Sloths seldom descend from their arboreal homes because they do not need to drink water; they get as much hydration as they need from leaf consumption.
The leaves a sloth consumes are not easy to digest, and do not provide much in the way of energy, hence the animal's slow movement. Sloth’s stomachs have several compartments, loaded with tiny bacteria that help break down the cellulose of leaves, yet their metabolism remains sluggish. Most sloths sleep up to two-thirds of the day and maintain a very low body temperature.
There are several species of sloth, which can be classed as either two-toed or three-toed, a somewhat misleading classification. Both classes have three toes on their back feet, but the two-toed varieties have two fingers on their front hands or paws. Three-toed sloths are slightly larger than their two-toed cousins. On the other hand, two-toed varieties are a bit faster.
When cornered by a predator, such as the harpy eagle or the jaguar, a sloth can be quick, using its long claws to discourage attacks. The sloth is often successful in defending itself. Most early sloth deaths are due not to predators, but to electrocution from contact with electric wires.
Though the rainforest is diminishing, only one sloth species, the Maned Three-Toed Sloth, is considered endangered at this time. Further destruction of the rainforest will likely result in endangered classification for the other four species of sloths. However, currently, sloths have adapted to human encroachment on their territory, and since they do not pose a threat to humans, they are frequently left alone.
Written by Tricia Ellis-Christensen
