Cameras on dolphins searching for mines offer impressive footage (VIDEO)  

They belong to the US Navy

The US Navy has had a Marine Mammal Program since 1959, training dolphins and sea lions to detect mines and other underwater threats. Now, they strapped cameras onto the dolphins to help scientists understand their behavior. The footage left researchers speechless as they were spotted hunting like never before, eating fish and even venomous sea snakes.

In the video you can even hear the sounds they make, using them as sonar to pinpoint their prey, while happy sounds can also be heard after their meal. The footage reveals that the dolphins expand the diameter of their necks and retract their tongues to swallow their prey through suction, whereas until now it was thought that their main strategy was to lunge towards the fish.

The six dolphins used for the experiment have been trained to detect and mark mines. They go out into the open ocean once a day. They can leave and not come back if they wish and in the long history of the program, some have.

They clicked with pauses every 20-50 milliseconds. When they approached their prey, the clicks became more frequent until they reached a continuous sound. When they came into contact with the prey, the sound continued until they swallowed the fish. The scientists noticed that the sound of their hearts can also be heard in the video, while they observed the movements of the dolphins’ eyes when they approached their prey.

They were impressed by eating poisonous sea snakes, playing a game of cat and mouse. In fact, a dolphin consumed eight snakes, without being affected by their poison.

The dolphin clicked as it approached the snake and then swallowed it whole. This particular snake can cause neurotoxicity even after ingestion and its venom is considered very dangerous. Perhaps because the snakes eaten appear to have been young, they had less venom. Perhaps because the dolphin was raised in captivity and has not learned to hunt in packs, it chose to eat this dangerous prey.

The new study offers a wealth of knowledge about dolphin behavior.

The findings are a surprising addition to the literature, providing a detailed analysis of dolphin hunting in the open ocean that would be very difficult to achieve with free-ranging dolphins.

The research was published in PLOS ONE .