Millions of years of isolation on a continent of extremes has seen Australia evolve some pretty freaky animals.
We’ve got kangaroos that live in trees, sex-crazed antechinus and snakes capable of delivering enough venom to kill dozens of humans with a single bite.
There are a lot of tall tales when it comes to our fantastical fauna and it can sometimes be pretty hard to tell fact from fiction.
So much so that we couldn’t fit every Australian animal “myth” into one article.
So here’s part two of debunking Australian animal “myths” (spoiler: you’ve probably guessed by now but the quotation marks are there because despite our better instincts, some of these myths turned out to be true).
If you missed part one or you like reading terrible things about quokkas, you can catch it here.
And if you’ve got any more Australian animal myths you want busted (or confirmed), let us know.
Do dogs prefer facing north to poo?
OK, so this article is about native animals and sure, most dogs aren’t native.
But we’re shoehorning this in because the Australian dingo qualifies as native under federal environmental law, and this is just too good a rumour not to look into.
Have you ever seen a dog doing circles before settling on a spot to poo?
If you’re like most rational people, you’ve probably filed this alongside such dog behaviours as growling at the doormat, howling at sirens and chasing one’s own tail.
But thankfully, researchers from the Czech University of Life Sciences Prague aren’t like most rational people, and decided to investigate.
They monitored 70 different dogs of 37 breeds making 1,893 bowel motions and 5,582 wee stops over a two-year period.
At first, the orientation of the dogs appeared fairly random.
But there can be local variations in the strength and direction of the Earth’s magnetic field, which is measured by geometric observatories.
When they excluded days of magnetic instability, they found our canine friends were picking up on some serious electromagnetism.
“Analysis … of dogs sampled during calm magnetic field conditions revealed a highly significant axial preference for north-south defecation,” they wrote in their paper published in Frontiers in Zoology.
According to their data, the dogs showed a strong preference for facing either north or south when relieving themselves, and significantly had an almost complete aversion for aligning their bodies on an east-west axis.
Other animals such as birds are known to be able to detect electromagnetic fields, which they use for navigation, so it’s not a huge stretch to presume dogs might also have this capacity.
However, it’s unclear what evolutionary benefit there could be for a dog to align themselves north-south while heeding the call of nature.
And this is only one research paper that doesn’t even look at dingoes specifically.
Still, if you’re ever lost in the bush and have your dog with you, you could use this as a way to get your north bearing.
But remember it’s magnetic north, and probably not accurate on days of magnetic variability.
So, it’s probably best to still use a compass.
Do kangaroos lure their predators to watery graves?
Kangaroos have a reputation for being pretty feisty — especially during the mating season.
When the big males are fighting each other or an unwitting passerby, they can be a pretty intimidating presence.
But as grass eaters, surely they’ve no reason to use violence outside the competition for mating rights? Right?
There is, however, a rumour doing the rounds that if kangaroos are being chased by predators, they’ll lead them into water, and drown them.
The verdict? True, but it’s a question of intent.
“There’s a very strong instinct — kangaroos will go to water if they’re threatened by a predator,” kangaroo ecologist Graeme Coulson from the University of Melbourne says.
Dr Coulson says his neighbour lost two dogs that way.
“It was a bull terrier that went in and it was drowned. Then he got another dog, another bull terrier, and it died the same way.
“So he got a third dog, and he kept it locked up.”
But given kangaroos get no benefit from killing an animal, it’s likely they’re actually entering the water in the hope they’re not followed.
Running into water is a common defence mechanism for a number of herbivores, according to Matt Hayward from the University of Newcastle.
“In Africa, herbivores do the same thing — they run into water if they’re being chased,” Professor Hayward says.
“I’ve seen wild dogs chase impala into dams.
“I’ve seen buffalo waiting in water surrounding by hyenas.
“But they tend to just wait [in the water] until the animal gets bored.
“I don’t think it’s about trying to drown them.”
Is it true whales and dolphins don’t get cancer?
There’s a curious paradox when it comes to whales and cancer.
Because of their huge size, they have vastly more cells than humans and should therefore be at much greater risk of cancerous cell mutations.
However, the opposite is true: the occurrence of cancer in whales as well as other cetaceans like dolphins is far lower than in people — a phenomenon known as Peto’s paradox.
Research published this year in Proceedings of the Royal Society B found that cetaceans have rapidly evolving tumour suppressor genes (TSGs).
These can slow down cell division, repair mistakes in our DNA and kill off cancerous cells before they spread out of control.
According to the researchers, the tumour suppressor gene turnover rate — the rate that genes are gained and lost through mutation — is 2.4 times faster in cetaceans than other mammals.
And they think this has allowed whales to develop a more efficient system of preventing cancer as they evolved their large body size.
But there’s a difference between less cancer and no cancer, according to marine and estuarine ecologist Olaf Meynecke from Griffith University, who says the idea that whales never get cancer is a myth.
“They get ulcers, uncontrolled cell growth and even skin cancer,” Dr Meynecke says.
“I am not sure who put the myth out there, but clearly someone who has not looked at a whale closely.”
Can black cockatoos signal that rain is on the way?
According to folklore, when black cockatoos take wing, there’s rain on the way.
Depending on where in Australia you are, you may have heard this applied to red-tailed black cockatoos, yellow-tailed black cockatoos, or to Carnaby’s black cockatoos — the so-called “rainbird”.
Obviously rain doesn’t fall every time a black cockatoo flaps its wings, but there may some broad truth to the claim, according to bird expert Bob Doneley from the University of Queensland.
“There is absolutely no way I would discount this,” Professor Doneley says.
“Most of this is built on observations by Indigenous people as well as people living in the bush and being familiar with the birds’ body language.”
Rain is a cue for many birds to become more active and in some cases, to breed, he said.
They’ll be more likely to be moving around more, and actively calling and vocalising, which increases the chances that people will notice them.
“That will look to us ignorant people like birds flying around, getting excited.”
For the Carnaby’s black cockatoo, their migration coincides with the rain season, according to Adam Peck from BirdLife Australia.
Carnaby’s migrate to the wheat belt at the time when the winter rains start, and the success of their breeding season depends on how much rain falls, he says.
What isn’t completely understood yet is how exactly the birds know rain is on the way, according to Professor Doneley.
“It’s probably to do with changes in the air — the humidity, even the sound of distant thunder,” he says.
“There are millions of years of genetic evolution for birds to know when rain is going to arrive.”
