How do dolphins hunt? Research project offers bird’s-eye view of dolphins

Scientists trying to understand the hunting behavior of bottlenose dolphins have found a unique solution: equipping them with video cameras.

The result is the most remarkable insight into the dolphin hunting process seen so far, showing crucial details of their search for prey – and recording their victory cries when they catch it.

A dolphin is even seen chasing and eating several poisonous sea snakes, a surprising and dangerous choice for a meal that scientists can’t fully explain.

The videos, released Wednesday, are an “incredible addition” to scientific knowledge about dolphin hunting on the high seas, biologist Brittany Jones of the National Marine Mammal Foundation, a San Diego-based nonprofit group, said in a statement. E-mail. The scientists observed “eye movements, catching strategies, and movements of the lips, tongue, muscles, and gulars.” [lower jaw] region during prey capture events that would be very difficult to achieve with wild dolphins.

Jones worked closely with the authors of a research paper based on the video published in the journal PLOS One. The lead author is Dr. Sam Ridgway, former chairman of the foundation and renowned marine mammal veterinarian and scientist, who died in July.

Under Ridgway, the foundation has partnered with the US Navy on its Marine Mammal Program, which trains bottlenose dolphins and California sea lions as underwater “guard dogs” to detect explosives and other objects in ports and at sea. About 70 dolphins and 30 sea lions participate in the program, also based in San Diego, and the partnership has produced more than 1,200 scientific studies of their physiology and behavior.

B: “Dolphin S” drills into the seabed to grab a fish. B & C: The white of its eye, or sclera, faces forward when catching prey.Ridgway et al., 2022, PLOS ONE, CC-BY 4.0

For the latest study, researchers fitted six US Navy dolphins – identified in the study only as B, K, S, Y, T and Z – with a harness and an underwater video camera capable of record their eyes and mouths. The cameras also made audio recordings of all the noises.

Study co-author Dianna Samuelson Dibble, a foundation biologist, said the video and audio gave scientists unique insight into the hunting behavior of bottlenose dolphins. Although the dolphins in the study are not wild, they have frequent hunting opportunities on the high seas, and scientists expect wild dolphins to hunt similarly.

Of particular note are the sounds they make while hunting. The dolphins made “clicks” every 20 to 50 milliseconds as they searched for prey, a rapid noise that only they can hear clearly and which appears to be a form of echolocation – the natural sense of sonar used by dolphins , porpoises and toothed whales to detect fish by bouncing sounds off them.

“This became evident during video scans as the dolphins identified the next prey target,” Dibble said in an email. “The background noise escalated rapidly, masking the sounds of many dolphins as the animal picked up speed in pursuit.”

The dolphins then began to hum as they approached, followed by a victory cry when they caught their prey. “The buzzing and screeching was almost constant until the fish was swallowed,” she said.

About Ethel Nester

Check Also

Rapper Wakko the Kidd is shot dead during a robbery in North Hollywood

An aspiring rapper who was shot multiple times in a violent North Hollywood home robbery …