Koala information: not a bear but a marsupial with a pouch. Australian koala facts and pictures.
She looks like a cute and cuddly teddy bear and she certainly fooled Sydney Australia’s early European settlers. They were the first to call her a bear.
In fact we now know that the koala is a marsupial, not a bear, but the name has stuck and even today many call her a koala bear.
Both the bear and the koala are mammals – as are humans. Bears (and humans) are placental mammals. Mothers carry their young inside the womb until it is fully developed.
Koalas are marsupials, a sub-class of mammals. Young koalas are born in an embryonic form after a short gestation of around 35 days.
The young joey develops in its mother’s pouch over the next six months.
When it leaves the pouch to be weaned the joey is at approximately the same stage of development as many newly born placental mammals.
The word marsupial comes from the Greek word marsupion which means “little purse”.
Most marsupial females have an abdominal pouch with mammary glands inside. The newborn climbs up into the pouch, attaches to the teat and suckles.
Koala facts: its closest relative is the Australian wombat.
Although they went their separate evolutionary ways about 42 million years ago, the koala still shares with the wombat a backwards opening pouch.
For the wombat, a burrowing marsupial, this backwards pouch protected its young from flying dirt.
A koala joey, high up in the trees, doesn’t need this sort of protection. But the koala’s backward pouch clearly hasn’t affected its survival rates and so it remains to this day.
The koala is the largest arboreal (tree climbing) mammal in Australia.
Its natural distribution is north, south and west of Sydney throughout much of eastern Australia. This distribution has been widened by the koala’s introduction onto islands off Tasmania and the east and south coasts of Australia.
It is not found in Western Australia and the Northern Territory, other than in zoos or animal parks.
Koalas are short and stocky and vary in size and colour, from 7 – 9 kilograms with light grey fur in warmer Queensland to 10 – 14 kilograms with darker brown fur in cooler Victoria. Males can be up to 50% larger than females.
Koalas are non-gregarious, or solitary, animals.
When not breeding they spend over 90% of their time alone (although a mother may have her joey with her).
Even during the mating and breeding period koalas have been observed to spend some 85% of their time alone.
Each animal has its own home range where it lives and sources its foliage.
Home ranges can be as large as 135 hectares (1.35 km²) in Queensland or may cover less than one hectare (10,000 m²) in Victoria.
The size of the home range is a function of the nutritional value of the leaves the koala needs to survive, with Queensland soils and leaves being of significantly lower nutritional value than those in Victoria.
There are very few natural home ranges in Sydney Australia. The koala’s native habitat has all but gone from the city. Many trees have been cleared for houses and bushfires have wiped out others.
What Do Koalas Eat?
Koalas are specialised feeders. They mainly eat the leaves of a sub-genus of Eucalyptus called Symphyomyrtus.
Although it includes some 400 species, koalas have been observed to feed on, or be found sitting in, only 120 species.
Of these, only 14 can be considered to be primary food sources.
The koala rarely drinks as such.
It obtains most of its water from rain droplets, moisture on leaves and the water content of the leaves themselves.
The young leaves favoured as koala food are 50-60% water. Older leaves are drier, being about 40-50% water. Occasionally, in drought, koalas will drink from ponds.
Cute Koala? Here’s Why
Why do we find the koala so appealing?
The animal’s relatively big head and eyes, medium size body, short limbs and tiny feet are similar to the proportions found in human toddlers.
Researchers have suggested that the body proportions of a sitting 12-18 month old child are similar to the head to body proportions of a koala.
The head to body proportions of human babies and toddlers elicit strong maternal and care responses and this likeness may trigger our positive emotional response to koalas.
This picture of my uncle Nol was taken over 50 years ago. Today it couldn’t be legally taken in New South Wales. Here, State laws prohibit handling these animals for photos. It’s considered to be too stressful for them.
At Sydney zoo you stand close to a koala sitting on its branch for a photo, you don’t hold it.
Other states have slightly different laws, but the holding of koalas like this for photos is today permitted only in Queensland.
Having said that, when Oprah Winfrey or important visiting politicians visit Sydney they are often invited to hold, a koala. I guess basic koala facts don’t apply to them!