Koala: unparalleled superstar of the mammal world

Name(s): Koala (Phascolarctos cinereus)

Habitat/range: Eucalypt forests of south-eastern Australia, from South Australia, through Victoria, ACT, NSW, and Queensland.

Size: In the north of their range, female koalas weigh around 5kg and males 8kg. In the south, koalas are bigger and much better looking; female koalas can weigh up to 12kg, whilst the biggest males can push 16kg. A classic example of Bergmann’s Rule for all of you ecology nerds out there. They grow to about the length of a baguette (60–85cm).

Diet: Eucalypt leaves.

Conservation status: Listed as Vulnerable by the IUCN, and Endangered under the EPBC Act in QLD, NSW, and the ACT.

Superpower/fun fact: The bellow of a male koala can be heard more than 1km away and has a pitch akin to that of an elephant.

Photograph of a koala hanging onto a branch
Koala. Credit: Darcy Watchorn

In Australia, there is one creature so absolutely and unrelentingly popular that it effortlessly steals the attention and adoration of people all around the world. I’m talking, of course, about the Taylor Swift of the animal world – the koala. Now, straight off the bat, allow me to make one thing clear, lest I get in trouble with other koala scientists. Koalas are not bears. They’re marsupials, like possums and kangaroos. Believe it or not, the wombat is their closest relative.

Yet despite their popularity, for many people, the koala remains a nocturnal enigma of Australia’s forests. Rarely heard and even less frequently seen, many of us know little of this sleepy furball. So please, sit back, relax, and enjoy as I share the koalas’ dirty little ecological secrets. But just remember, every time you utter the name “koala bear”, a koala scientist dies.

Just why is the koala so intensely popular? They don’t fly, glide, swim, hunt, burrow, or recklessly swing through the trees with their tail. In fact, they’re the only tree-dwelling marsupial that doesn’t have a tail. It might be said, then, that koalas do very little to capture our imagination.

It’s all to do with their eyes. You may or may not have heard the saying – “eyes to the side, run and hide; eyes to the front, love to hunt”. Now, we all know that koalas are vegetarians, carelessly munching on as many as 1 kg of eucalypt leaves per day. Leaves contain very little energy, however, so koalas limit their energy use and sleep or rest for 20 hours a day (not because leaves make them drunk, as is commonly thought). Leaves are also where they get most of their water – it’s rare to see a koala drinking. But to be fair, it’s rare to see them doing anything.

Unusually for vegetarians, koalas have forward-facing eyes, in part because they have few predators. Forward-facing eyes also provide better depth perception for living in trees and jumping between branches. For while koalas are normally sleepy and slow, they can move with surprising speed and agility through the tree-tops, aided in part by the presence of two thumbs on each front paw which provide excellent grip. Males sometimes chase and fight each other over territory or females, and females often run away from males that are feeling frisky.

Close-up photograph of a koala sleeping in a tree
Koala. Credit: Darcy Watchorn

If you’ve been camping in the bush along eastern Australia, you may be familiar with the rather horrifying demonic screams and bellows that accompany these sexual advances. The pitch of a male’s bellow is about 20 times lower than expected for an animal the size of a miniature poodle; it’s more akin to that of an elephant’s bellow – an animal 400 times larger!

Should a male taste sweet success and a koala joey be born 33 days later, it will drink milk in the mothers’ pouch until it’s 6-months old. Then, like all good mums, our koala mother feeds her joey a special type of poo she makes. Yummy! This poo, called “pap”, has all of the things needed for the joey to transition from a milk-based diet to a leaf one.

Now, back to the forward-facing eyes. It’s this eye position, plus their body size/shape that makes them so endearing, and thus so very popular. They look just like furry little human children, tricking us into feeling some strange kind of parental affection! This isn’t lost on the Australian tourism industry either; koalas bring in over $1 billion each year to our economy!

The koala is emblematic of Australia’s marvellously unique mammal species, and arguably no other species on Earth evokes the same emotional connection, making them a critical symbol of conservation and environmental awareness. If this isn’t enough for you to vote for them, I don’t know what is. Maybe some pap?

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