Marine biologists at the University of California have captured video footage of dolphins hunting and eating for the first time. The study was published in the journal PLOS One.
The scientists attached special cameras to the dolphins that recorded audio and video. The angle of view made it possible to think through the smallest details of eating fish and hunting. Each animal caught about a hundred fish. Some have been kept in a saltwater pool, while others have been observed in the open ocean.
Specifically, one of the dolphins ate 8 small yellow-bellied sea snakes (Hydrophis platurus). Eating such prey has never been observed before and did not cause signs of poisoning in the dolphin.
Cameras were positioned to identify prey and observe details, lip movements and swallowing of fish. The recording showed that echolocation was used by dolphins to search for prey from afar, and vision was used when approaching – this was revealed by tracking the movement of the dolphin’s eyes, which can also be seen in the recording.
During the search, the dolphins clicked at intervals of 20 to 50 ms. As the prey approached, the click intervals changed to a buzz and then a squeak. The sizzle was a series of clicks of varying duration, peak frequency, and amplitude. The screams continued as the dolphin caught and swallowed the prey. If the fish broke free and swam away, the dolphin kept chasing and sonar clicks became rarer. During capture, the dolphins’ lips swelled, exposing almost all the teeth, and the throat was enlarged.
The scientists’ work has shown that such an approach can be used for further research that will lead to a better understanding of the hunting and feeding of endangered species.