How water rats are killing toxic cane toads in massive numbers by ripping out their HEARTS with ‘surgical-like’ precision to avoid being poisoned
- Scientists have discovered that water rats are learning to hunt pesky cane toads
- Cane toads have been devastating Australia’s ecosystems since their arrival
- Water rats are killing cane toads by eating certain parts of them that aren’t toxic
Scientists have discovered water rats are learning to kill cane toads without dying from their toxins.
Cane toads have been devastating Australia’s ecosystems since they came Down Under from Central America in the 1930s.
But now, water rats are killing the animals by eating certain parts of them that are free from their toxins.
Reproductive biologist Dr Marissa Parrott was working in Western Australia’s Kimberly region when she saw the dire effects cane toads had on local wildlife.
Even large crocodiles are found dead with small cane toads inside their stomachs.
Reproductive biologist Dr Marissa Parrott believes the rats most likely sliced opened the toad’s chests with their teeth – which is less poisonous than their backs
Dr Parrott said that while working near a creek in WA’s Emma Gorge, she saw more proof of water rats killing off cane toads.
‘I found a number of very large dead cane toads, and all of them were lying on their backs with almost surgical type incisions down their chest. Every day I went there, there were up to five new bodies,’ she told VICE.
‘We found that in all the cane toads, the heart and liver had expertly been removed, and the gallbladder, which contains toxic bile salts, had been removed and placed outside the body.’
Dr Parrott set up infrared cameras and discovered that local water rats were behind the deaths.
She said that within just two years of cane toads moving into the region, water rats had figured out how to disable, kill and eat the toads, despite them having killed a number of predators.
Despite not being able to get a close-up of the killing, Dr Parrott believes the rats most likely sliced opened the toad’s chests with their teeth – which is less poisonous than their backs.
Dr Parrott discovered that water rats are killing cane toads by eating certain parts of them that are free of toxins
She said the rats would then use their paws to take out the toads’ organs.
‘They didn’t eat as many medium-sized toads, but when they did, it was fascinating to note that as well as the heart and liver they had also eaten one or both of the thigh muscles after stripping away the toxic skin,’ she said.
‘We’re not sure if they just wanted a bigger payoff for their efforts in overpowering the toad, or if it was easier to subdue the toads by holding down the legs first. Interestingly, they never attacked the leg muscles on the larger toads.’
Cane Toads in Australia
About 3,000 cane toads were released in the sugarcane plantations of north Queensland in 1935.
They now number well into the millions, and their still expanding range covers thousands of square miles in northeastern Australia.
They are considered pests, and government eradication efforts include asking residents to help collect and dispose of them.
Cane toads are large, stocky amphibians with dry, warty skin, and are native to the southern United States, Central America, and tropical South America.
Cane toad poison is a mix of toxins that primarily affects the functioning of the heart. It is present throughout their bodies and is secreted as a milky liquid from the parotoid glands located over the toad’s shoulders.
SOURCE: National Geographic