Kukri snakes cut toads and frogs before sticking their heads in their bodies and eating their organs one by one while the prey is still alive, scientists say.
Biologists have published three studies, each of which details the horrific eating behavior of one of three different species of kukri snakes in Asia.
The three closely related snake species, all of the genus Oligodon, keep the prey alive for “up to a few hours,” according to the study’s authors.
Below is one: the Taiwanese kukri snake (Oligodon formosanus), with its head buried deep in the abdomen of the bull frog (Kaloula pulchra).
In the bloody attacks observed in nature, the toads fought vigorously to escape and “avoid being gutted alive,” but their efforts were in vain.
Aggressions can last up to a few hours, depending on the organs the snake removes first.
An Ocellated kukri snake (Vietnam) pierced this poisonous common Asian toad and buried its head deep in the amphibian’s abdomen, as it probably ate its organs. However, as seen in the photo, the kukri snake proceeded to swallow the whole toad.
The images also show the ruthless snake repeatedly rotating its body longitudinally in an elaborate representation known as the “death shot.”
“We believe that the purpose of these deaths was to rip off organs and then swallow them,” said study author Henrik Bringsøe, a herpetologist based in Køge, Denmark.
Two of the three articles describing the horrific behavior, all written by Bringsøe, have been published this month.
One reports on the terrible feeding strategy of the Taiwanese kukri snake (Oligodon formosanus) and the other on the same strategy of the ocellated kukri snake (Oligodon ocellatus).
The other paper, published in September last year, describes the same behavior in the small-banded kukri snake (Oligodon fasciolatus).
The three closely related species of snakes of the genus Oligodon have developed this unusual and distressing behavior.
Still from the images of a Taiwanese kukri snake that has cut the abdomen of an ox frog (Kaloula pulchra) and has extracted various organs that it is biting and chewing. The video shows the snake in the process of swallowing. The observation took place in Hong Kong. Below you can see the full images of this meeting
Interestingly, it has also been reported that these species feed in a more conventional way, swallowing their entire prey.
Therefore, it is likely that this alternative strategy has evolved to be able to eat with much larger animals.
One of the new studies reports two cases from Hong Kong where it was observed that Taiwanese kukri snakes unmolded bull frogs with bands.
In one case, the snake had opened the frog’s belly and inserted its head into the frog’s abdomen, before repeatedly performing its death.
In the other case, the frog’s organs had been forced out of his abdomen.
The second recently published research paper details the behavior of the ocellated kukri snake, which was observed eating the toxic Asian toad (Duttaphrynus melanostictus) in Vietnam.
The black-spotted Asian toad is known to secrete a potent toxin from the parotid glands in the neck, but it does not appear to have any lethal effect on the predator.
Initially, it was seen that the snake had buried its large head to the abdomen of the amphibian.
Eventually, however, the snake swallowed the whole toad despite its toxicity, providing evidence that kukri snakes are resistant to cardiac glycoside toxins from toads.
The less recent September document marked the announcement of the eating habit, described as “never before had I witnessed a snake.”
He described multiple cases of small-banded kukri snake (Oligodon fasciolatus) feeding on Asian toad with black spots.
At the time, the research team noted that smaller toads of this species used to be swallowed whole, possibly because they are less toxic than adults.
A small-banded kukri snake with its head inserted on the right side of the abdomen of an Asian toad with black spots, in order to extract and eat the organs. Tissue from a collapsed lung (top left) and possibly adipose tissue, covered by a clear liquid foam that mixes with air bubbles in the lung when it expires. The upper leg is covered with frothy blood, also mixed with air bubbles from the collapsed lung.
In one of the new articles, Bringsøe and his team include new details of a new observation of the small-banded Kukri snake (Oligodon fasciolatus).
The team reveals that it prefers to swallow the whole prey after making the same “death throw.”
This has led scientists to be more inclined to believe that the size of the prey is what determines the exact manner of the snake during dinner.
“We hope that future observations can uncover additional aspects of the fascinating eating habits of kukri snakes, although we can call them horrible,” Bringsøe said.
All research papers are published in the peer-reviewed journal Herpetozoa, open access.