Dolphins Plan Their Dives, Study Reports

As new research in the Journal of Experimental Biology suggests, dolphins carefully plan their hunting dives to make sure they do not run out of oxygen while exploring the ocean’s depth. While dolphins are incredibly resilient creatures, they need to carefully plan their oxygen levels when going on hunts. That is because, if they are not careful they can easily drown while on the hunt.

Scientists have long wondered how dolphins are able to know how much oxygen they need while diving. In the new study, researchers from the University of La Laguna shed light on the mystery by revealing that the mammals use information from previous dives to know how far down to go.

The team used small recorders to analyze the locations and vocalizations of 37 Risso’s dolphins as they hunted for food. They then made note of the sounds the mammals made while hunting. The noises — known as buzzes — are much faster than the sounds dolphins make while attempting to catch prey.

This showed that the dolphins began to echolocate as soon as they left the surface. In addition, once the dolphins found success hunting at a certain depth they would change the frequency of their clicks to indicate that they should return there during future dives.

Researcher believe such behavior is “probably to gain information on the depth distribution and availability of prey and to respond swiftly to rapid changes in habitat structure at different depths,” said lead author Patricia Arranz, a researcher at the University of La Laguna, in a statement.

The study also showed that the dolphins would continue to echolocate as they came back up to the surface. That behavior would continue whether they were hunting or not. As a result, they likely exhibit such traits as a way to plan ahead and search for the location of their next hunt.

“Information about prey, learned throughout the dive, was used to plan foraging in the next dive,” the team wrote in their research, according to Tech Times “Our results demonstrate that planning for future dives is modulated by spatial memory derived from multi-modal prey sampling (echoic, visual and capture) during earlier dives.”

This sheds light on dolphin behavior and gives insight into a never before seen characteristic. The team plans to next look at other marine mammals to see if they have similar practices.