Creature feature
Tuesday 29 June 2004
The two-toed sloth is just hanging around here at London Zoo
The sloth (choloepus didactylus) spends most of its time hanging upside down from the forest canopy. It eats, sleeps, mates and nurses its young in this position, but they will also sit upright in the fork of a tree and occasionally descend to the ground.
They avoid going down to the ground because of the risk posed by predators such as jaguars and ocelots. The two-toed sloth is nocturnal, sleeping during the daytime and waking at night.
Sloths move very slowly, one limb at a time, about 0.5km per hour, however if danger is present they can move much faster.
The two-toed sloth weighs 7-9 kg (17-20 lb). It is usually brown in colour, with lighter fur around the face and head. The under fur is dense, often matted, while the outer fur is fine and sleek. The hair grows from its belly to its back so that the rain will run off more easily. There are two claws on each front foot and three on the hind feet, which is why it is called the two-toed sloth.
Surprisingly, sloths are actually much better at swimming than walking. In the Pantanal region of Brazil, they have to swim to survive the annual floods, which happen every spring.
In the wild the sloth eats mainly leaves, flowers and shoots with some fruit, insects, small mammals and nestlings. As with all of our animals at London Zoo, we try to replicate their natural diet as closely as possible.
Amazingly, sloths digest their food for over a month! They have very large stomachs, where the food remains until it passes into their intestine. And they only defecate and urinate once a week!
Sloths have extremely poor eyesight and hearing, but their sense of smell is excellent and they can find a mate by following the scent of another's dung heap!
When a baby is born, it is carried on the mother's body for six to nine months, hooking itself into her fur. After one month it begins to take leaves chewed by the mother and after two months it can pick its own leaves while hanging onto its mother. It reaches full size in two to three years and can live for up to 30 years.
Sloths are unusual among mammals in that their body temperature varies with the surrounding temperature. Most mammals sweat to maintain a constant body temperature, but sloths can vary their body temperature and so sweat less, which conserves fluids.
