I must confess that ‘S’ seems to have the most interesting and varied animals of any letter. I could’ve wrote posts about spiders, snakes, sharks, sheep and salamanders and yet I have decided to post about Sloths. There are currently 6 species of sloth in the world; all of which are Folivarian. This means that the vast majority of their food comes from leaves and shoots. Folivoria literally translates as “leaf-eater”. Sloths are found in jungles in Central and Southern America. Sloths are called many different names by the tribes that live around these jungles including: Ritto and Ridette. These names all roughly translate as sleep or lazy. Sloths are therefore lazy leaf-eaters.
A sloth’s fur is quite remarkable. The fur has a special function: the outer hairs grow in a direction opposite from that of other mammals. In most mammals, hairs grow toward the extremities, but sloths, who spend much of their time with their legs above their bodies, have hairs that grow away from the extremities to provide protection from the elements while the sloth hangs upside down. The fur is also their primary means of protection. Sloths themselves make excellent habitats for other organisms. The sloth most of its time stationary and therefore things like beetles, moths and fungi are able to ‘camp’ inside the sloth’s hair. It is actually the fungi which sometimes gives the sloth a green colour. This led many people to believe that sloths are the only green mammal; whereas, in fact, there are no green mammals. Sloths are arboreal creatures (like Koalas) and have many unique adaptations to survive. Firstly, because their diet mainly consists of leaves that are hard to digest and supply little nutrients, sloths have a very slow digesting stomach. The stomach is so slow that a fully-fed sloth’s stomach may account for 2/3 of its body weight! It can take a sloth up to 1 month to digest a single meal!
Sloths also possess a extremely gifted tongue. The tongue of a sloth may protrude from its mouth up to 12 inches. This tongue acts very much like a giraffe’s neck; allowing the sloth to reach leaves from a great distance away. Having a diet low in nutrition means that the sloth has had to come up with ways to conserve energy. One way it does this is by having a very slow metabolism. A sloth’s metabolism is at least half of what is ‘normal’ for a mammal of equivalent size. What is more, a sloth has a much lower resting temperature than many mammals – sometimes below 30’c!
As mentioned before, a sloth is very ‘lazy’. They very rarely move and only move when it is essential to do so. This means that a sloth has about a quarter of the muscle mass of a similar sized animal. Their top speed (if they are in immediate threat from a predator) is about 4 metres per minute – even this is rarely done because it requires enormous amounts of energy. They get around this lack of movement by hanging. A sloth has specialised hands and feet which allows them to claw themselves upside down on branches. This requires literally no effort on the sloth’s part and they can do this indefinitely. This allows them to remain in prime position to eat nearby leaves. The hanging ability of a sloth is so remarkable that it is possible for them to hang onto a branch even after they have died! In fact, hanging is one of main causes for their death. Sloths have a rather poor ability of distinguishing between tree branches and electric cables and so many sloth die from electrocution!