Sloths

Basic Information

Sloths are among the slowest-moving mammals on Earth, traveling at a maximum speed of only 0.17 miles per hour on the ground!

Sloths sleep about 8 to 10 hours a day in the wild — often while hanging upside down from tree branches to stay hidden from predators!

There are six species of sloths alive today, divided into two families: two-toed sloths and three-toed sloths!

Despite their names, all sloths actually have three toes on their hind limbs, but two-toed sloths have only two fingers on their front limbs while three-toed sloths have three!

Sloths can turn their heads almost 180 degrees, allowing them to scan their surroundings without moving their bodies!

The scientific name for sloths, “Folivora,” comes from Latin words meaning “leaf eater”!

Sloths have existed on Earth for about 64 million years, making them one of the oldest mammal families still alive today!

A sloth’s fur grows in the opposite direction from most mammals — from belly to back — which helps rainwater run off while they hang upside down!

Sloths rarely come down from trees and may spend their entire lives in the canopy of a single group of trees!

The closest living relatives to sloths are anteaters and armadillos, and together they form a group called Xenarthra!

Scientific Classification

Sloths belong to the mammalian order Pilosa, which they share with anteaters!

Two-toed sloths belong to the family Megalonychidae and the genus Choloepus!

Three-toed sloths belong to the family Bradypodidae and the genus Bradypus!

The six living species of sloths are the Brown-throated three-toed sloth, Pale-throated three-toed sloth, Maned three-toed sloth, Pygmy three-toed sloth, Linnaeus’s two-toed sloth, and Hoffmann’s two-toed sloth!

The pygmy three-toed sloth (Bradypus pygmaeus) is the smallest sloth species and is critically endangered, living only on a tiny island off Panama called Isla Escudo de Veraguas!

The word “sloth” comes from the Old English word “slāwth,” meaning slowness or laziness!

Giant ground sloths like Megatherium existed during the Ice Age and were the size of elephants, standing up to 12 feet (3.66 meters) tall!

Sloths are part of the superorder Xenarthra, a group of mammals found only in the Americas!

The scientific name of the three-toed sloth genus, “Bradypus,” means “slow foot” in Greek!

The sloth’s taxonomic suborder, Folivora, was previously called Phyllophaga, but this name was already used for a genus of beetles!

Collective Nouns and Groups

A group of sloths is called a “snuggle,” “bed,” or “slumber” of sloths!

Sloths are mostly solitary animals and rarely gather in groups except during breeding season!

Baby sloths stay with their mothers for about six months to a year before going off on their own!

Unlike many mammals, sloths don’t form social bonds or family groups once babies leave their mothers!

Adult male sloths are territorial and will defend their territory from other males!

A mother sloth with her baby is sometimes referred to as a “sloth and baby”!

Unlike some other mammals, sloths don’t have a hierarchical social structure or dominant leaders!

When sloths do encounter each other in the wild, they typically ignore each other unless it’s mating season!

During rare social interactions, sloths communicate through vocalizations that sound like high-pitched whistles or squeaks!

Geographic Distribution and Habitat

Sloths live exclusively in the tropical rainforests of Central and South America, from southern Mexico to northern Argentina!

Three-toed sloths prefer humid forests with continuous canopy, while two-toed sloths can adapt to more fragmented habitats!

Sloths spend almost their entire lives in the treetops, coming to the ground only about once a week to poop!

Sloths prefer trees with lots of lianas (woody vines) which provide additional climbing paths between trees!

The Pygmy three-toed sloth lives only on a tiny 4.3 square kilometer island called Isla Escudo de Veraguas off the coast of Panama!

Sloths prefer living in cecropia trees, which have hollow trunks and branches that provide shelter!

The Amazon rainforest is home to the highest diversity of sloth species!

Sloths don’t build nests or dens but sleep cradled in the fork of a tree branch!

Due to deforestation, sloth populations have become increasingly isolated in fragmented patches of forest!

Life Cycle

Sloths in the wild typically live 20–30 years, but those in captivity can live up to 50 years!

Two-toed sloths generally live longer than three-toed sloths by about 5–10 years on average!

Baby sloths have a high mortality rate, with only about 30% surviving their first year in the wild!

The oldest recorded sloth in captivity was a two-toed sloth named Paula who lived to be 50 years old at a German zoo!

Sloths reach sexual maturity at around 1–5 years of age!

A sloth’s slow metabolism contributes to its long lifespan compared to other mammals of similar size!

Captive sloths often live longer than wild sloths because they don’t face predators and receive regular veterinary care!

A sloth’s heart beats only 20–40 times per minute when resting, compared to a human’s 60–100 beats per minute!

Weight and Size

Adult three-toed sloths typically weigh between 8 and 10 pounds (3.6-4.5 kg), about the same as a house cat!

Two-toed sloths are larger, weighing between 8 and 20 pounds (3.6-9 kg), similar to a medium-sized dog!

Three-toed sloths measure about 24 inches (60 cm) in body length, while two-toed sloths can reach up to 29 inches (74 cm)!

A sloth’s arms can be up to 20 inches (50 cm) long, which is longer than their entire torso!