Science & Technology

The charismatic yet sleepy mammal.

Koalas are mammals native to Australia. They are often incorrectly referred to as Koala bears, most likely because they have a similar appearance to bears. Koalas, however, are marsupials, meaning they carry their babies in a pouch on their bellies. They live in coastal areas and make their habitats in large groups. The cute bear-like creature spends most of its time, nearly 80% of its life, sleeping and lounging around.

Ancestry and Evolution of the Koala

Scientists believe that koalas have roamed the Australian continent for more than 25 million years. They adapted over time to changing weather conditions that dried out the forests and toughened their diet. Today, the mammals can chew and shred tough eucalyptus leaves.

There are a few different types of koalas, including the Brown Koala, the Gray Koala, and the Gray-Brown Koala. Each is native to a different region in southern Australia. Brown Koalas, the largest type, come from the Victorian region. The Gray Koalas of Queensland, Australia, are smaller and much more threatened by predators and habitat loss. The Gray-Brown Koalas from South Wales are at risk of extinction, with only 16,000 left in the wild.

Appearance

Weighing between 8 and 33 pounds, koalas are not quite the size of a bear, though their long, shiny black nose and furry figure make them look like one. The mammals can reach three feet in height, with a round head topped by large furry ears. Their short arms and legs and long, sharp claws assist with their love for tree-climbing. The marsupials have opposable thumbs and three fingers that allow them to easily grip any surface and scale to great heights.

Diet and Habitat

Koalas are herbivores, but with a specific taste. They feed solely on eucalyptus gum tree leaves, which are so thick, tough, and fibrous that other animals cannot eat. Adapting to the harshness of the plant, koalas are equipped with an extra-long digestive tract, called a cecum, that breaks down the leaves to allow for digestion. They will also sometimes eat soil or gravel to assist.

Koalas make their homes at the tops of the eucalyptus trees along the coastlines, forests, and some inland areas of southern Australia. They live alone in their trees but congregate with a much larger group that functions in a hierarchy. One dominant male oversees and controls the koala society and has first dibs when it comes to mating season. Forest fires and deforestation have severely affected koalas and their habitats.

Reproduction and Lifespan

Around two to three years of age, a female koala reaches sexual maturity and is ready to have a baby. Males need a little longer, developing mating skills between four and five years old. A mother koala gives birth to a single baby called a joey. A joey will live in its mother’s pouch until it is around seven months old. From there, the joey holds tight to its mother’s back for another few months.

Koalas in the wild live between 13 and 18 years old. They spend about 80% of their day sleeping, resting, and lounging, with the other 20% primarily spent eating. They do not travel or migrate; they stay in their home, unless they are forced to relocate.

Predators

A lack of native mammalian predators allows koalas to have a rather carefree lifestyle. There are very few animals that hunt koalas for food. On the predator list are birds of prey, dingos, and humans who hunt them for their pelts (fur). Bacterial diseases affect the koala populations far more than predators. Domestic animals like dogs spread these diseases when they attack and bite a koala.

Deforestation is a major contributor to the loss of koalas, and forest fires destroy their habitats. Nevertheless, the Gray-Brown Koala is the only one of the species currently at risk of extinction.

Fascinating Facts About Koalas

• Koalas are born blind and without ears.
• Koalas got their name from an Aborigine word meaning “no drink.”
• Koalas can sleep for 18 hours per day.

1. Koalas are not bears but marsupials, meaning they carry their babies in a pouch on their bellies.
2. They feed solely on eucalyptus gum tree leaves, which are so thick, tough, and fibrous that other animals cannot eat.
3. The Gray-Brown Koala is the only one of the species currently at risk of extinction, with 16,000 left in the wild.