No suitcase needed. Toads have poisonous sacs that help them move around the world

There is a frog attack underfoot. Not really. according to a new study In which the DNA of 124 species of toads was analysed, you can now find them on six of the seven continents, with colonies recently expanding rapidly in East Africa.

And some scientists believe that a large part of the toad’s acquisitions are linked to how the warty, tough-skinned creatures are built.

“They’re full of venom,” said Chris Raxworthy, co-author of the study and curator of herpetology at the American Museum of Natural History. as it happens Host Nil Koksal.

“Many toads have these huge glands at the back of their heads that we call auricle Glands and they’re full of toxins.”

Such toxins that can cause death to any predator that tries to eat them.

raxworthy He says his research found that the toad’s toxic parotid glands evolved millions of years ago as the species rapidly moved onto new continents, giving them an “edge” and “the ability to move forward with their world conquest.”

the study, Published in Proceedings of the Royal Society B On October 15, claims were made that glands were an effective anti-predator strategy Helped give small amphibians a fighting chance to survive.

where their journey began

Raxworthy says it all started 61 million years ago, with evidence suggesting the species originated in South America. about 30 million years Later, Raxworthy says that the Todes successfully invaded Africa.

Exactly how these tiny amphibians crossed the great Atlantic Ocean is still unclear.OdourThe scientists in the study have some hypotheses. The first is that they could use Antarctica as a stepping stone.

“About 30 million years ago, Antarctica was much warmer than it is now,” Raxworthy said. “And the positions of the continents were slightly different so the dispersal distances were not so far.”

Second Postulate This is so that the amphibians could move directly across the pond using floating mats of vegetation, a type of technique known as rafting. It may sound crazy, but Raxworthy says he’s seen it with his own eyes.

“When you have tremendous rainfall, especially in the tropics on big rivers, your banks will be eroded and trees will fall down and you’ll get huge pieces of vegetation washed downstream and out to sea,” Raxworthy said.

“So it’s not hard to imagine that a bunch of toads would wash up out to sea in one of these mats of vegetation. And if after a few weeks they still survive and wash up on the beach, they could actually start a new founder population.”

The scientists behind the findings “have done a really good job of linking biogeography with business evolution, which is not very common in the literature,” says Richard L. Eisner, a professor of biological sciences at Southern Illinois University who was not involved in the study.

“A key factor in their success are those glands because any predator, including unfortunately many native marsupial hunters, that tries to hunt them gets a mouthful of that venom and it can make them sick or cause death,” Eisner said.

Expansion of toads in modern times

There is also a modern example of this, which is going on right now in Africa. As of 2014, Madagascar was one of the last places in the world untouched by toad invasion.

That was until the Asian common toad showed up in the East African country’s largest port.

“They probably came on a shipping container,” Raxworthy said. “Since that time, they have now spread to a radius of 30 or 40 kilometers around their original attack point.”

The presence of this invasive species immediately set off alarm bells for scientists, not only because of how rapidly they were spreading, but also because of the threat they pose to Madagascar’s unique biota.

Eisner says it briefly mirrors what happened when cane toads were first introduced to Australia in the 1930s to control native cane beetles that were damaging sugarcane crops.

according to Queensland Government website, The toads were not successful in controlling the beetles, but they were highly successful in spreading.

“They’ve basically taken over the entire continent,” saysS. Eisner.

Raxworthy worries that Madagascar’s native fauna may suffer the same fate. And he says that as was the case with cane toads in Australia, humans appear to be unwittingly the toads’ greatest allies in their quest for world domination, with the toads possibly arriving by cargo ship.

“It’s sad to me … in Madagascar, especially where I’ve been working for many years, to see these toads coming in and attacking,” Raxworthy said.

“Now we’re at a point where we don’t really know how to control it. We just have to let this biological experiment run.”