Dolphins with GoPro cameras captured incredible close-up footage of their hunting habits.
The videos surprised scientists as the dolphins used suction to feed and eat poisonous sea snakes.
Watch the view of the dolphins and hear the sonar clicks and victory squeals as they hunt.
Videos from GoPro cameras strapped to a pair of Navy-trained bottlenose dolphins reveal the ocean animals’ hunting habits for the first time.
Scientists from the National Marine Mammal Foundation fixed the dolphins with their cameras and set them free in San Diego Bay. They captured hours of video and audio that reveal some secrets of dolphin life.
It turns out that the animals use suction to feed, swallow poisonous sea snakes and squeal for victory after a successful hunt.
A video, below, shows the dolphin’s face as it tracks down a fish, grabs it and swims a victory lap. It’s not just the footage that’s incredible. The dolphin’s cries and audible calls are equally revealing. The dolphins emitted sonar clicks as they searched for prey. As they approached a fish, the clicks quickened to a hum, with a squeal as they caught and swallowed their meal.
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.
Ridgway helped establish the US Navy’s Marine Mammal Program more than 60 years ago. This is the program that trained the dolphins in this study. He also founded and led the National Marine Mammal Foundation, the nonprofit behind the new paper. He has devoted his entire career to understanding the behavior, physiology and health of ocean mammals – especially bottlenose dolphins.
These videos are one of his latest research efforts. For the first time, Ridgway and his team have recorded close-up video and audio of dolphins hunting and eating live fish. An article about the video was published in PLOS ONE on Wednesday.
“Dr. Ridgway was very proud of these findings and was excited to know that this highlight was going to be published in PLOS ONE,” said Brittany Jones, a scientist at the National Marine Mammal Foundation who worked with the study’s authors as they completed the their work. , he told Insider in an email.
“He has always been willing and excited to review the video and audio of these fishing sessions and recently spoke of his appreciation and admiration for [co-authors] Dianna Samuelson Dibble, Mark Baird, the amazing animals and animal care staff who made this research possible,” Jones said.
A dolphin’s diet included poisonous sea snakes
Shockingly for the researchers, one dolphin ate eight venomous sea snakes – a behavior never seen before in dolphins.
The video below shows one of these sea snake meals. After catching the snake, the dolphin jerks its head and emits a loud “victory squeal”.
You got it; He went quickly.
This is a yellow-bellied sea snake and is very venomous. The scientists speculated that this is why they only observed dolphins playing with snakes and releasing them, not consuming them – especially not consuming eight of them.
Ridgway and his colleagues couldn’t believe their eyes at first. 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 meals of sea snakes, the researchers said.
“Perhaps because the snakes they ingested were thought to be young, they had less venom,” Linnehan said.
Dolphins appear to be suction feeders
The sea snake video is also revealing because the dolphin caught its prey in the open ocean, indicating that it used suction to capture and swallow its food. Researchers previously assumed that bottlenose dolphins use a technique called ram feeding, where they capture prey simply by closing their jaws around it.
However, in videos of the dolphin with a camera on its side, the researchers could see the dolphin’s lips open, tongue retract and neck expand. They think that all these subtle movements increase the space in the dolphins’ mouths and create negative pressure for suction.
“With years of experience feeding dolphins, we had not observed this lip movement,” the researchers wrote in their paper. “Rather than catching fish in a serrated beak trap, the dolphins appeared to be primarily sucking fish.”
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