This snake rips open a living toad to feast on its organs

It’s the first time that scientists have observed this behavior in snakes

In this image, a small-banded kukri snake has used its needlelike teeth to tear open the abdomen of a toxic Asian black-spotted toad so it can feast on the toad’s insides.

W. Suthanthangjai, H. Bringsøe et al/Herpetozoa 2020

Some snakes eat toads by swallowing the creatures whole. Others slash a hole in a toad’s stomach, shove their heads in and gorge on organs and tissues. And all this happens while the amphibian is still alive.

“Toads don’t have the same feelings and can’t sense pain in the same way as we can,” says Henrik Bringsøe in Køge, Denmark. “But still, it must be the most horrible way of dying.” Bringsøe is an amateur herpetologist, someone who studies reptiles and amphibians.

In a new study, he and some colleagues in Thailand now document three such attacks by small-banded kukri snakes (Oligodon fasciolatus). Their study was published September 11 in the journal Herpetozoa. Animals like crows or raccoons were already known to eat some toads in a similar fashion. This, however, was the first time scientists had observed this behavior in snakes.

Small-banded kukri snakes get their name from their teeth. Those needlelike teeth resemble the curved kukri knives used by Nepalese Gurkha soldiers. The snakes use those teeth to tear into eggs. And like most snakes, O. fasciolatus also feeds by swallowing its meals whole. The species may use its teeth to evade a toxin from the Asian black-spotted toad (Duttaphrynus melanostictus). To defend itself, this toad secretes a poison from glands on its neck and back.  

It was the children of coauthors Winai and Maneerat Suthanthangjai who first stumbled upon a snake feasting on the innards of a Asian black-spotted toad. This was near Loei, Thailand. The toad was already dead. But the whole area was bloody. The snake had clearly dragged its prey around. It was clear “that it had been a true battlefield,” Bringsøe says.

Two other episodes at a nearby pond involved living toads. Winai Suthanthangjai watched one fight that lasted almost three hours. The snake battled with the toad’s toxic defenses before finally winning. A kukri snake saws into its prey using its teeth like a steak knife, he says. The snake eats by “slowly cutting back and forth until it can put its head in.” Then it feasts on the organs.

The reptiles may attack in this manner to help them dodge a toad’s poison, Bringsøe says. However, it also may be a way for the snakes to eat prey that is too large to swallow.

Erin I. Garcia de Jesus is a staff writer at Science News. She holds a Ph.D. in microbiology from the University of Washington and a master’s in science communication from the University of California, Santa Cruz.

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