The US Navy Put Cameras on Dolphins And The Footage Is Revealing

The first film ever captured from the perspective of dolphins freely hunting off the coast of North America is accompanied by a flurry of clicks and triumphant squeals.

The US Navy fitted cameras to its dolphins, who are taught to spot underwater mines and guard some of the country's nuclear arsenal, for a scientific research that was published last year. The dolphins were then given free freedom to hunt in San Diego Bay.

To the amazement of the researchers, the cunning marine animals delivered thrilling chases and even targeted poisonous sea snakes.

We still don't fully understand many fundamental aspects of these very gregarious and frequently disgusting cetaceans, including their regular feeding habits, despite the fact that they are well-known and widely popular creatures.

The general consensus among researchers is that there are at least two methods: sucking up prey like noodles from a dish and chowing them down like a state fair hot dog in between rides.

Yet a lot more was revealed by the video.

Six bottlenose dolphins (Tursiops truncatus) were equipped with cameras from the US National Marine Mammal Foundation (NMMF), which captured footage and audio over the course of six months. This new level of insight into these mammals' hunting tactics and communication has never been possible before.

Their lips and eyes were seen in startlingly off-angle positions when the recording equipment was positioned on their sides or backs.

While these dolphins are not in the wild, they are regularly given the chance to hunt in the open ocean as a supplement to their typical diet of frozen fish. As NMMF marine mammal veterinarian Sam Ridgway and colleagues said in 2022, it is thus conceivable that these creatures apply comparable techniques to their wild counterparts.

They noted in their research that dolphins "clicked practically continuously while they searched at intervals of 20 to 50 milliseconds." "Click intervals become shorter as the prey gets closer, eventually morphing into a terminal buzz and a shriek. Fish contact resulted in buzzing and shrieking that continued virtually nonstop until the fish was eaten."

More than 200 fish, including bass, croakers, halibut, smelt, and pipefish, were captured by the dolphins with cameras fastened to them. The smelt frequently threw themselves into the air in an effort to flee the cunning hunters.

Yet, the dolphins kept track of their every move and used a method they had previously seen in wild dolphins, swimming upside down to provide their swiveling eyes a clear view.

According to Ridgway and colleagues, "These dolphins appeared to employ both sight and hearing to detect food." "The dolphins always utilized echolocation to locate fish from a distance. Close up, it looked that echolocation and eyesight were employed in tandem."

The cameras also captured the sound of the animals' racing hearts as they struggled to keep up with the demanding activities. This footage showed that instead of ramming their prey to the ground, the dolphins used suction to gulp down their still-fighting prey with their remarkably powerful throat muscles.

The dolphins' neck muscles sprang into action, and their tongues retracted out of the way as they largely swallowed fish into the sides of their open mouths. Their muscles for sucking add to the negative pressure that is produced by the increased inner mouth space.

Although dolphins have been observed playing with snakes in the past, including river dolphins amusing a ridiculously huge anaconda, the video provided definitive evidence that dolphins may also consume these animals.

Eight very deadly yellow-bellied sea snakes were eaten by one dolphin (Hydrophis platurus).

The researchers reported that "our dolphin demonstrated no indications of disease after swallowing the little snakes," however they recognized that this may possibly be atypical behavior given that the dolphins are captivity animals.

"Maybe the ingestion of this unusual meal was caused by the dolphin's lack of experience feeding with dolphin groups in the wild."

Just before the study was released, Sam Ridgway, the study's principal author, passed suddenly at the age of 86, leaving behind a significant body of research.

According to NMMF ethologist Brittany Jones, "His innovative approach to teaming with Navy dolphins to better understand the species' behavior, anatomy, health, sonar, and communication will continue to teach and inspire future scientists for centuries."

According to NMMF's website, the dolphins trained by the Navy "work in open water virtually every day."

"They have the option to swim away, and several have throughout the years. But the majority do."

This research was published in PLOS ONE.