How does an Australian bird eat a poisonous Cane Toad?

In Australia, the poisonous Cane Toad (Bufo marinus) is not native to the country. It is an introduced, invasive pest living in tropical northern Australia that has rapidly spread due to the lack of predators. Animals that eat the warty amphibian die from the toxic secretions from large glands on the Cane Toad’s shoulder. The cardiac toxins can give all predators, such as snakes, goanna lizards, and even freshwater crocodiles, a deadly heart attack.

Exactly 101 Cane Toads from South America were introduced into the sugar cane plantations in Cairns, Queensland, Australia, in 1935 to eat the larva (grub) infesting the cane plants. In 2009, they crossed the state border of Queensland to travel into Northern Territory, more than 2,000 kilometers from Cairns. The Cane Toad is a prolific breeder and there are now, in 2022, an estimated 2 billion of them, although no one really knows how many there are. 

Rick Shine, professor in biology at the University of Sydney, told the BBC in 2017 that the Cane Toad only moves during the wet season, and can travel 50-60 kilometres (31-37 miles) per year, but tracking studies have shown that many hop less than 10 metres (33 feet) a day. 

In 2022, the Cane Toads have now crossed another state border, and are in the dry state of Western Australia, says Lee Scott-Virtue, the president of Kimberley Toadbusters, established in 2004. The toads are adapting to dry, desert conditions, and they are predicted to take five years to reach the city of Broome in coastal Western Australia, says Lee Scott-Virtue. Scientists are concerned about the rapid spread of the Cane Toad because they are a threat to the endangered species in the area.

However, there is one animal that seems to know exactly how to eat the Cane Toad without killing itself.

Birds, such as hawks and crows seem to be less susceptible to Cane Toad toxins. These birds flip the Cane Toad on its back and then rip out their insides to eat the intestines and gizzards, leaving the toxic shoulder glands untouched.

Now, in 2022, Rick Shine, who has studied toads for 20 years, has heard of an Australian bird that can eat a Cane Toad whole.

The Australian White Ibis (Threskiornis molucca) in the Threskiornithidae family, closely related to the African Sacred Ibis (Threskiornis aethiopicus), has developed an ingenious unique method for eating the Cane Toad whole.

Emily Vincent, who operates the invasive species programs at the environment charity Watergum, has received many pictures and videos from community members of the Australian White Ibis eating Cane Toads.

The Australian White Ibis flips the Cane Toad into the air, then wipes the toad in the wet grass or rinses the toad in a nearby water source. The Ibis repeats the actions, without damaging or mutilating the toad, before swallowing the toad whole. Emily Vincent calls these actions the ‘stress, wash, and repeat’ method.

Professor Rick Shine and Emily Vincent both think that the Australian White Ibis ‘stress, wash, and repeat’ method is a promising sign that native animals are learning to adapt to the Cane Toads, which could help to control their population numbers.

Location of photographs: Nairobi, Kenya and Northern Territory, Australia

Photographer: Martina Nicolls (Ibis), Cane Toad photograph: Benjamint444 2012, Benjamin.photos@gmail.com

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM