The sloth is best known for its name. They live in distant South America and are rarely seen in zoos, but few have heard of these animals with a reputation for being the laziest of all. They are really very slow, but not because of laziness, but because they have a very slow metabolism, and the structure of the body simply does not allow them to be fast.
Origin of the species and description
Sloths make up a whole suborder of Folivora, belonging to the order of edentulous. Two families have survived to the present: three-toed sloths or Bradypodidae, described by D. Gray in 1821; two-toed sloths, they are also Megalonychidae – they were described by P. Gervais in 1855.
Earlier, scientists considered them to be close relatives – after all, they are very similar in appearance. But then it turned out that this is an example of convergent evolution – although they belong to the same order, they are related to each other no more than anteaters, and their ancestors were very different. The closest ancestors of two-toed sloths were generally gigantic and walked on the ground.
The most ancient edentulous appeared in the Cretaceous period and survived during the great extinction that marked its end. After that, they flourished: 30-40 million years ago, ten times more species of sloths lived on the planet than there are now, and the largest of them were the size of an elephant.
They lived in South America at that time, and had practically no competition, which allowed new species to appear. But then South America connected with North America – at first this allowed them to expand their range by moving there, but then, due to increased competition, many species began to die out.
This process began about 12 million years BC, first affecting the largest of them, then those that were slightly smaller – some large sloths even managed to catch a person, as evidenced by the marks from the tools on their bones and the remains of processed skins. As a result, only the smallest of them managed to survive.
Appearance and features
Dimensions, like other signs, may vary depending on the species, but not excessively. As a rule, their length is 50-60 cm, and their weight is 5-6 kg. The body is covered with light brown hair. Often it has a green tint due to algae that can grow right in it – this allows sloths to be hardly noticeable in the foliage.
The coat is harsh and rather long, the head is overgrown with it so much that sometimes you can only see it eyes. Sloths resemble monkeys, however, they are only very distantly related to them, the closest related animals are anteaters.
They have a good sense of smell, but this is the only well-developed sense organ – their hearing and vision are not sharp. Their teeth do not have roots, as well as enamel, which is why they are classified as incomplete teeth. There are two sections in the skull, the brain is placed in one of them, it is small and has few convolutions.
They are distinguished by the structure of the fingers – they are very tenacious and resemble hooks. This allows them to feel great in trees, giving odds even to monkeys in the ability to climb them – although not in the speed with which they do it.
All sloths have one thing in common for which they were given the name – slowness. Among all mammals, they are the most leisurely, and they move not just slowly, but very slowly, and in general they try to make a minimum of movements.
G. Fernandez de Oviedo y Valdes, one of the first to compile a detailed description of Central America, described the sloth as the most disgusting and useless creature he had ever seen. However, not everyone will agree with him – many visitors to zoos love them very much, as well as tourists who happen to see them in nature.
Where does the sloth live?
These animals have a slow metabolism and low body temperature, and therefore they need warmth and they settle only in regions with a warm climate. Their homeland is South and Central America, where they inhabit quite vast spaces. They live one by one in dense forests, most often at great distances from each other.
The northernmost country where two-toed sloths live is Nicaragua, and three-toed sloths cannot be found north of Honduras. From these states and to the south, they inhabit the rest of Central America, as well as the lands adjacent to the northern coast of Latin.
The southern borders of the range of the two-toed sloth lie in the north of Peru. They live in Colombia and Venezuela, in the northern states of Brazil. The range of the three-toed sloth is much wider, it not only includes all the same lands, but also extends much further south.
They can be found in Ecuador, throughout Peru, Brazil, Paraguay, Bolivia and Uruguay, as well as northern Argentina. Thus, they live almost throughout South America. Although this does not mean that there are very many of them: within the range there may be vast spaces where not a single sloth can be found.
Interesting fact: The only thing that sloths have to get down from a tree is to defecate. If other arboreal animals do this without descending, then sloths always descend to the ground, even though they are in the greatest danger of being caught by a predator at these moments.
In addition, the descent itself takes them a very long time – a trip there and back can easily take half a day. But they rarely have to empty their intestines, about once a week. After that, they carefully bury their feces in the ground.
Now you know what the sloth eats. Let's see what he eats.
What does a sloth eat?
On their menu includes:
- leaves and flowers of trees;
- small reptiles.
For the most part, they eat leaves, and everything else just supplements their diet. In particular, they love cecropia – both its leaves and flowers. In captivity, it is imperative to give them, because it is not easy to keep sloths in zoos. They prefer to eat young shoots.
Lizards and insects are not specially hunted, but if they happen to be nearby and let themselves be caught, they can eat them too. This happens infrequently due to the slowness of the sloths – usually the prey simply eludes them, so you have to continue chewing the leaves.
The sloth's stomach is complex and adapted to extract all possible nutrients from the food that enters it. The rest of their digestive system is also complex, which compensates for the low nutritional value of the leaves. Symbiotic bacteria help in the digestion of sloths.
Digestion takes a very long time, sometimes for weeks. This is not very convenient, because more than 65% of a sloth's body weight can be food digested in its stomach – it is quite difficult to carry it.
But this allows them, if necessary, not to eat for a long time – usually herbivores very quickly begin to starve and lose strength, but this is completely unusual for sloths. In addition, due to their slow metabolism, they are not afraid of poisons contained in the leaves of some trees in their habitats.
Peculiarities of character and lifestyle
The time of wakefulness differs by species – for example, three-toed sloths are awake and are in search of food during the day, but two-toed sloths, on the contrary, sleep most of the day, and only when dusk comes they decide that it is time to eat. They usually live alone and rarely meet with relatives due to the fact that they move little.
But if they do meet, they are almost always friendly, they can feed on the same tree and stay nearby for quite a long time – up to weeks. At the same time, they communicate little: they are generally silent, and almost do not change their behavior – as they hung most of the day almost without movement, they continue to do it, but only together.
Spend more than half of the day in a dream, and often while hanging on a branch head down. The speed of the sloth is about 3 meters per minute, and on the ground it is half as much. When he descends to the ground, his movements become comical – it seems that it is very difficult for him to get around even a very small obstacle.
They also move through trees differently than other animals: for example, a monkey grabs branches and is held by muscle strength. But the sloth has almost no muscles, so it does not hold on to a branch, but hangs on it – its claws are curved like hooks and allow you not to apply force. This saves a lot of energy, but you can only move very slowly.
But for the sloth itself, this is not a disadvantage, for him such a speed of movement is quite normal, because he also does everything else no faster: for example, he chews food for a very long time, he needs a lot of time even just to turn his neck. Fortunately, nature endowed him with the ability to turn it 180 degrees.
The sloth's sluggish life is determined by its biology: it has a very slow metabolism, which means little energy, and a low body temperature of about 30-32 degrees, and during sleep it drops by another 6-8 degrees. Therefore, one has to save on every movement, with which his body successfully copes.
Social structure and reproduction
Usually sloths just live alone and meet only by chance. If a male and female two-toed sloth meet, they can start mating – they do not have a specific season of the year for breeding, it can occur in any month. Things are different for three-toeds – the season comes in July, when they deliberately look for each other.
Females take care of offspring, but males have no interest in him, and usually leave the pair long before he is born. At first, the cub hangs on the mother all the time and feeds on her milk, and from the second month it gradually begins to move to the leaves – at first they serve as an additive, and then gradually occupy an increasing place in the diet.
But, like everything in the life of sloths, this process can take a long time: individuals of some species begin an independent life as early as 9 months, but others feed on their mother's milk up to two years. And they can literally hang on their mother until the age of 6 months, after which they become too heavy.
The size of an adult sloth reaches 3 years, at the same time it becomes sexually mature. They live in nature up to 10-15 years, in rare cases longer. When kept in captivity in good conditions, the sloth may well live up to 20-25 years.
Interesting fact: Since sloths do not make sudden movements, they almost do not need muscles, as well as a strong heart to forcefully supply them with blood during exercise. Therefore, the weight of the heart in a sloth is only 0.3% of the body weight, and the muscle mass is 25%. According to both of these indicators, he is one and a half to two times inferior to a person who, in turn, is far from a champion himself.
Sloths' natural enemies
Among his natural enemies are:
But in reality, most of these predators become a threat to the sloth only when he descends to the ground, and he does this very rarely. This is the secret of the survival of precisely those species of sloths that were small in size when the large ones became extinct – they are able to hang on rather thin branches where large predators cannot reach them.
Therefore, even jaguars capable of climbing trees only have to lick their lips and wait for the sloth to decide to get off the tree or at least go down lower, to the thick branches. And the wait will be long, and sloths are not very tasty due to the almost complete lack of muscles – therefore they are not a priority prey for cats.
In addition, sloths are well aware that danger can threaten not only on the ground, but also when descending to the lower branches, and specially climb higher. True, another enemy may meet here – predatory harpies. If a sloth is seen flying from above, they will certainly attack him, because his greenish coat and inactivity play into his hands.
And yet they prefer not to climb too high either, so it turns out that because of predators, their habitat on trees is greatly reduced. These should be rather thin branches closer to the top, but not the very top, so that the birds do not see. When the flood comes and the sloths swim, crocodiles may try to eat them.
People also act as their enemies: the Indians hunted sloths since ancient times and ate their meat, lined their saddles with skins, and used their claws for jewelry. However, hunting has never acquired an excessive scale that would have threatened these animals with extinction – after all, they were not a priority prey for humans either.
Population and species status
Neither two-toed nor three-toed sloths are among the protected species, and are considered to be the least threatened species. In some places they are still hunted, although they are not of great commercial value. The scale of hunting is relatively small, and it does not threaten the population.
Inactivity serves them as a reliable protection, as well as a solitary life – it is difficult to notice them among the trees, and even if the hunt is successful, it is usually possible to get only one sloth of small size and weight. Therefore, most often people kill them by chance meeting while hunting for other animals.
Populations are more threatened by other misfortunes, primarily the reduction in the area on which they can live, due to increasing human development. Power lines are a big problem, because they are stretched even through the very thick of the forest, so sloths sometimes try to climb them and die because of the current.
But so far, these threats are not yet so critical and the sloth population remains fairly stable. So, three-toed sloths quite densely populate forests near the Amazon – for example, their density in the state of Manaus is estimated at 220 individuals per square kilometer. It is lower elsewhere, but still the total number is estimated at tens of millions of individuals.
Interesting fact: Sloths can still do some things quickly, at least relatively quickly – they swim well. In the Amazon basin, floods occur frequently, it happens that the earth remains under water for several months. Then they have to swim between the trees – even though they look rather clumsy, but they develop a speed of 4-5 km/h.
The sloth is a small and friendly animal . They may seem very clumsy and slow, but many find them charming. The rhythm of their life is very measured: most of the day they sleep, the rest of the time they hang on trees and eat leaves. And they do it so slowly that you can’t even immediately notice that they are not sleeping.