How Garbage Chickens Learned to Wash Poisonous Cane Toads

An ibis carrying a toad

An ibis spotted eating a toad in Logan, near Brisbane

There are few Australian animals more reviled than the white ibis.

He earned the nickname “bin chicken” for his penchant for scavenging food from wherever possible, messily raiding trash and often stealing food right out of people’s hands.

But the native bird may have figured out how to revise its bad reputation.

He has developed an “ingenious” method of eating one of the one animals Australians hate the most: the cane toad, a toxic and pervasive pest.

First introduced to Australia in the 1930s, cane toads have no natural predators in the country and have devastated native animal populations.

The skin of the toad contains venom which it releases when threatened, causing the rapid death of a heart attack for most animals that come into contact with it.

Hence Emily Vincent’s surprise when community members started sending her photos and videos of ibises “playing” with amphibians.

Ms Vincent, who runs invasive species programs at environmental charity Watergum, says the behavior has been reported up and down the east coast of Australia.

“The ibises were throwing toads, throwing them in the air, and people were just wondering what the hell they were doing,” he told the BBC.

“After this, they would always clean the toads in wet grass, or go down to a nearby source of water and rinse the toads.”

He believes it’s evidence of a “stress, wash and repeat” method birds developed to rid toads of their toxins before swallowing them whole.

“It’s really a lot of fun.”

“Smart” birds.

It’s not the first time birds have been spotted eating cane toads, Professor Rick Shine of Macquarie University told the BBC.

They appear to be less susceptible to venom than other animals, such as snakes, mammals or crocodiles.

An ibis carrying a toad

Toad expert Rick Shine says he’s never heard of the behavior before

But they can still die from too much and it tastes “awful,” says the prof. shine.

So as the species spread across Australia, birds like hawks and crows figured out rather quickly how to eat around the venom glands on their shoulder.

They would flip the toads onto their backs and tear out their innards, leaving the glands intact.

But this is the first time Professor Shine – who has studied toads for 20 years – has heard of birds using a method like this to eat them whole.

“Ibises have an unfair reputation… [but] this shows that these are intelligent birds,” says Ms. Vincent.

“They actually forced the cane toad to get rid of the toxin itself, they didn’t have to mutilate it in any way. The cane toad is doing all the work for them.”

Population control

Professor Shine and Ms Vincent both say it’s a promising sign that native animals are learning to adapt to toads, which are now estimated to number over 2 billion.

Some species are slowly recognizing that the parasites are “a poor choice for lunch” and there are suggestions that others are undergoing genetic changes that make them less susceptible to venom.

And then there are animals like the ibis that have figured out how to eat toads safely, which could help bring the population back under control.

“They have an incredible reproductive ability… so with every female cane toad that is removed from the environment, it is the prevention of up to 70,000 new cane toads each year,” says Ms. Vincent.

Cane Toad

In addition to poisoning predators, cane toads also eat small native animals

Most of the heavy lifting is done by animals Australia loves to hate, such as ibises, rodents or ants, says Prof. shine.

“All those animals are actually doing a great job as an invisible army that is reducing the number of cane toads every year,” says Professor Shine.

“So we should really be thankful for some of these unloved Australians.”

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