Koala mating habits, diet and habitat myths and misconceptions busted – ABC

By January 17, 2021 February 4th, 2021 Archive

ABC Science               By Anna Salleh                      Posted 17 Jan 2021

Koalas sure can look cute and cuddly on postcards, but they’re not when they’re mating. (Supplied: Taronga Zoo)

How far would you go to get away from someone you’re not interested in?

Would you climb out to the ends of a tree branch 15 metres above the ground in the hope that your suitor would not dare follow?

That’s what one female koala on the far north coast of New South Wales did after a night of being pursued by a male koala in a hoop pine tree.

There she stayed, clinging upside down, for about an hour, says Jo Immig, who witnessed the drama unfold in her backyard — complete with deep growling snorts from the male and high-pitched squeals from the female.

This female koala spent over an hour on the end of this branch trying to avoid a male. (Supplied: Jo Immig)

“She was quite exhausted,” says Jo, who yelled at the male to back off while putting cushions on the ground to break the female koala’s fall, should she be unable to hold on.

Eventually the male gave up and fell asleep and the female made her escape.

On another occasion, Jo saw a male koala in hot pursuit of a female higher up on a tree.

The female whacked the male on the head with her paw, then appeared to urinate on him.

“We think they’re cute and cuddly, and they must have cute and cuddly sex,” Jo says.

But as this How Deadly video shows, koala mating is pretty much the opposite.

YOUTUBECheck out How Deadly’s take on koalas.

Myth: Koalas are cuddly and friendly

An animal with a round head and fluffy ears is bound to capture your imagination — especially when it’s a mum carrying her joey.

But if you try to touch a wild koala, it can viciously lash out, says Alistair Melzer, a koala ecologist at Central Queensland University.

“The idea that it’s cute and cuddly is fine when it’s used to being handled in zoos, but in the wild it is going to bite and scratch — and its claws are much sharper than a cat’s,” Dr Melzer says.

Mating can appear to us as rather non-consensual and aggressive too, he says.

Koala claws are sharp and are capable of inflicting serious damage. (AdobeStock)

KOALA-FRIENDLY HINT: If you find a distressed koala and need to pick it up, sneak up behind it and throw a blanket over its back so you can bundle it up while staying protected.

Deidre de Villiers, a koala ecologist with Endeavour Veterinary Ecology in Queensland, says female koalas have a range of strategies to put a male off when they’re not interested.

Despite Jo’s observations, Dr de Villiers is not so sure these include weeing on the male. She thinks the female probably urinated because she was stressed.

But avoiding conflict is certainly an option.

“Females can go right out to the edge of a branch before it starts to break, whereas the male will back off if it starts bending too much.”

But males can counter by blocking the female’s escape route from a tree, she says.

Activities like this usually happen at night because koalas spend a lot of time apparently zonked during the day. And this has given rise to some interesting theories.

No, I’m not out of it. I’m just getting some much-needed rest. (Supplied: Koala Action Group)

Myth: Koalas are stoned on eucalyptus leaves

Eucalyptus leaves contain a lot of powerful-smelling chemicals that most animals wouldn’t tolerate, and one theory is these essentially drug koalas.

But the truth is they need to lounge around all day just to survive.

“There are good physiological reasons why koalas behave the way they do. We don’t need to refer to that old myth that the animals are doped out of their brains,” Dr Melzer says.

A key reason for loafing around all day is to devote energy to digesting eucalyptus leaves, which are tough, don’t provide a lot of energy and need to be detoxified.

Dr de Villiers says gum leaves are like “eating cardboard” and take days to digest by special bacteria in the koala’s gut.

Another reason for staying slow during the day is that koalas need to avoid overheating.

“There’s a cooling effect of tree trunks, so on hot days you’ll have koalas hugging tree trunks, sitting in the cool,” Dr de Villiers says.

This thermal image shows a hot koala hugging, and transferring heat to, a cool tree. (Supplied: Steve Griffiths)

Myth: Koalas are picky eaters

You might be surprised at how varied a koala’s diet is.

Another relaxed koala, just to remind you how cute they can be, despite everything. (Supplied: Deidre De Villiers)

Koalas mainly eat eucalypt leaves, but the species they prefer depends on their location.

So while in some areas there may only be one species of eucalypt they regularly eat, in others it can be more.

And koalas also nibble on other trees including wattle, casuarina, pine trees, camphor laurel, paperbarks and brush box, or tasty new shoots on paper bark trees (melaleuca).

They pick and choose leaves according to how juicy and nutritious they are, which can depend on the area’s soil moisture levels and the season, Dr de Villiers says.

But koalas don’t only need suitable trees to feed on at night. They also need trees that give them good shelter while resting and digesting during the day.

KOALA-FRIENDLY TIP: If you’re wondering what trees to plant to encourage koalas in your area, get advice from your state or territory environment department, local koala conservation groups or koala hospital.

It turns out the best shelter trees aren’t necessarily eucalypts, and many non-food trees have better canopy cover for keeping koalas cool.

“We’ll get koalas sitting in mango trees, camphor laurels and lilly pillies,” Dr de Villiers says, also adding hoop pines to the list.

One reason it’s so important for koalas to keep cool is they need to avoid losing too much water, but don’t be fooled by this next myth …

Myth: Koalas don’t drink water

For a long time, it was believed koalas only got water from what they ate, but they also drink dew from leaves or water that runs down tree trunks.

During droughts and bushfires they also seek water from sources like dams, swimming pools, bird baths, water bowls and even hand-held bottles.

YOUTUBEKoalas use drinking stations installed in trees too.

“Although we get the cute pictures, it’s really a sign the animals are in trouble,” Dr Melzer says.

“When you see koalas going to water bowls and swimming pools or approaching people, they’re in distress.”

Swimming pools can also mean death for koalas, even though they can swim quite well.

The problem comes when they can’t get a grip on anything at the edge of a water body. They can really struggle to get out.

KOALA-FRIENDLY TIP: Fence your pool with a material like perspex that can’t be climbed, or leave something floating in the water to help them escape. And when giving water to a thirsty koala, don’t force liquid down their throat. Let them lap at it.

Myth: Koalas wandering around urban areas are lost

As ecologist Matthew Crowther from the University of Sydney says, koalas like fertile flat land — which is also popular with humans.

As a result, the animals often live in urban environments, on the outskirts of big cities or sometimes in the middle of small towns.

Yet it’s still a misconception that koalas only live in the bush, and this leads to some unfortunate interventions.

“It’s common for the public to think that if they encounter a koala (in an urban area) that it must be distressed and must be rescued,” Dr Melzer says.

But the best thing is often to just leave them alone.

Remember, koalas are often on the ground when they’re going about their business, moving between trees.

“If it’s not obviously in distress, just enjoy its presence,” Dr Melzer says.

Koalas move more during the breeding season (July to February, depending on where you live) seeking out a mate.

KOALA-FRIENDLY TIP: Major threats to koalas in urban areas are being attacked by dogs and being hit by cars. So keep your dogs away from koalas or train them to be koala-safe. And slow down when you see a road sign warning koalas might be about

Koalas sometimes drink dew and water that runs down the trunk of trees. (Supplied: Jo Immig)

And what about drop bears?

You may have heard the koala has a relative, called Thylarctos plummetusthat “drops” down from as much as 8 metres on unsuspecting tourists and bites them on the neck.

Folk remedies that are supposed to repel the drop bear include wearing forks in the hair or Vegemite or toothpaste spread behind the ears, although apparently there’s no evidence to support these.

Or, of course, the drop bear itself.

But koalas do occasionally fall out of trees, Dr de Villiers says.

“It’s an occupational hazard for them when they’re mating or during storms or wind, and they can sometimes lose their footing.”

They just don’t attack people unless they’re defending themselves.

Dr Melzer wonders if the myth of the drop bear emerged from an earlier era when people used to hunt koalas.

In escaping, the koalas may have inadvertently fallen on people and grabbed them.

And then of course there’s the marsupial lion Thylacoleo carnifex that scientists say did drop from trees on their prey.

“If it’s true, it could have been a prehistoric drop bear … and it’s still out there,” Dr Melzer says with a laugh.