A Navy-trained bottlenose dolphin swallowed eight venomous sea snakes in one day, GoPro footage shows.
Dolphins have never been documented to eat sea snakes, only to play with them.
The attacks have baffled scientists, as eating venomous snakes can be dangerous.
A Navy-trained dolphin chased down and swallowed eight venomous sea snakes in one day, the first time scientists have documented such behavior.
Researchers at the National Marine Mammal Foundation in San Diego, California, strapped GoPro cameras to a pair of bottlenose dolphins, which the US Navy has trained to detect mines with their sonar calls. The dolphins were out of work for their video programming. Scientists wanted to see them doing what they do best: chasing fish.
One of the dolphins, however, chose a more unorthodox meal. Cameras caught her eating eight yellow-bellied sea snakes in one day. Before this study, which was published in the journal PLOS ONE on Wednesday, there was no documentation of dolphins eating sea snakes — only playing with them and releasing them. Ingestion of poisonous snakes can be dangerous.
In one video, below, the dolphin grabs a snake and swims with it for a while, bobbing its head repeatedly to swallow the prey. It then emits a high-pitched “victory squeal,” according to the study.
“The dolphin clicked as it approached the snake and then sucked it in with a bit more jerking of the head as the falling snake’s tail disappeared and the dolphin gave a sustained squeal,” the study authors wrote.
Did you see it? The sea snake was only visible for a split second before the dolphin grabbed it.
At first the researchers couldn’t believe their eyes. They looked for other fish that might look like a sea snake on camera, but found no other explanation.
“I have read that other large vertebrates rarely prey on the yellow-bellied sea snake. There are reports of leopard seals being eaten and then mauled. This snake has the potential to cause neurotoxicity after ingestion, and its venom is considered quite dangerous.” Dr. Barb Linnehan, director of medicine at the National Marine Mammal Foundation, said in a statement emailed to Insider.
The dolphin showed no signs of illness after its sea snake meals, the researchers said. They’re not sure why he was hunting such dangerous prey, but they suspect he simply would never have learned any better, having been born in captivity.
“Perhaps the dolphin’s lack of experience feeding with groups of dolphins in the wild led to the consumption of this extravagant prey,” the study authors wrote.
All the snakes he caught on camera were quite small and the researchers suspect they were newborns. The dolphin tried to catch a larger snake, but escaped.
“Perhaps because the snakes they ingested were thought to be young, they had less venom,” Linnehan said.
The research was led by Sam Ridgway, a prominent marine mammal scientist who earned nicknames such as the “Dolphin Doctor” and “the father of marine mammal medicine,” before he died at his home in San Diego in July.
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