Sloths questions

The living sloths belong to one of two families, known as the Megalonychidae ("two-toed" sloths) and the Bradypodidae (three-toed sloths). The name should in fact be rather "two fingered" or "three fingered" as all living sloths have in fact, three toes on their feet, and differ by the number of fingers on their arms (which were considered front feet in the past).

Almost all mammals have seven neck bones, including giraffes with long necks and whales with short necks. The few exceptions include manatees and two-toed sloths, which each have only six cervical vertebrae, and three-toed sloths with nine cervical vertebrae

Unlike other mammals, sloths cannot regulate their body temperatures, so they can only live in warm rainforest, where temperature varies little in the course of the year. Sloths have very low metabolic rates and maintain low and variable body temperatures (30–34°C or 86–93°F), regulating it by moving in and out of the shade in trees.

Sloth fur exhibits specialized functions: the outer hairs grow in a direction opposite from that of other mammals. In most mammals, hairs grow toward the extremities, but because sloths spend so much time with their legs above their bodies, their hairs grow away from the extremities to provide protection from the elements while the sloth hangs upside down.

Sloths live in the tropical rainforests of South and Central America. They have very low metabolic rates and would be unable to maintain the body temperature in non-tropical climates.

Sloths are classified as folivores. Leaves, their main food source, provide very little energy or nutrients, and do not digest easily. Even as much as two-thirds of a well-fed sloth's body weight consists of the contents of its stomach.