Researchers In Taiwan Document Formosa Kukri Snake Gutting And Eating Banded Bullfrogs

Southeast Asian snakes seem to have the monopoly on disemboweling and shredding their prey before eating.
Oligodon Formosanus Chewing Organs72
Oligodon formosanus chewed organs of Kaloula pulchra after they had been forced out of the abdomen. Screenshot from VN

Last year, researchers in Thailand documented how the small-banded kukri snake, (Oligodon fasciolatus) used its posterior maxillary teeth to slash open the abdomen of a live Asian black-spotted toad (Duttaphrynus melanostic), and ate the toad’s organs.

This year, the same researchers documented how the Taiwanese (or Formosa) kukri snake (Oligodon formosanus) also slashed the bellies of bullfrogs (in this case the banded bullfrog, Kaloula pulchra) to eat their guts and in some cases ate the amphibians whole. The researchers used citizen scientist video to document how the Taiwanese kukri snake cut open the abdomen of the amphibian, stuck its head in the abdomen of the bullfrog and performed a death roll, in what the researchers describe as an effort to tear off the frog’s organs so it could more easily eat them.

The researchers noted that with Oligodon formosanus, the enlarged posterior maxillary teeth are specialized for cutting open both reptile eggs as well as the skin of anurans. The teeth are very sharp, the researchers noted.

Oligodon Formosanus Eats Frog72

The head of Oligodon formosanus was inserted deep into the abdomen of Kaloula pulchra. Photo JL

In the first instance, Oligodon formosanus attacked a banded bullfrog, biting the lower part of the amphibians’s belly. The frog then proceeded to inflate itself as the snake cut open the belly and inserted its head into the abdomen. The scientists describe how the snake rotated its body while its head was in the abdomen of the bullfrog, a total of 15 times. After this, the video ended. The observer left the scene and returned later and wasn’t able to locate the frog or the snake and it is presumed the snake consumed the frog.

The second observation involving Oligodon formosanus details how the snake was observed biting and chewing the organs of an adult banded bullfrog after it had bit a hole in the frog’s belly. The snake worked at an apparent rapid pace and several of the frog’s organs spilled out of the hole created by the snake. It wasn’t observed if the bullfrog was alive or dead when the citizen scientist encountered the scene, but the snake continued to feed on the deceased frog.

The researchers note that Kaloula pulchra is an important prey item for Oligodon formosanus as well as Oligodon fasciolatus, as indicated in the 2020 study. This prey item is in addition to the other frogs, lizards, squamate eggs and turtle eggs that Oligodon formosanus has been observed consuming. Road-killed lizards are also on the menu of these snakes. Oligodon fasciolatus has been observed eating Duttaphrynus melanostictus toads. The complete paper, “Gruesome twosome kukri rippers: Oligodon formosanus (Günther, 1872) and O. fasciolatus (Günther, 1864) eat Kaloula pulchra Gray, 1831 either by eviscerating or swallowing whole” can be read on the Herpetozoa website.

Southeast Asian Snakes And Tearing Prey Apart

Southeast Asian snakes seem to be specialists in tearing their prey apart before eating. In addition to the kukri snakes, of which there are some 83 described species in the Oligodon genus, two mildly-venomous water snakes of Southeast Asia also tear their prey apart before eating.


Unique Feeding Behavior For A Snake; Tearing Its Food Apart Before Eating It


Fordonia leudcobalia feasts on hard-shelled crabs by crushing them first with its jaw, and Gerard’s water snake (Gerarda prevostiana) rips freshly molted crabs into bite sized chunks and then swallows those chunks whole.

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