Whales and Dolphins Simply Like to 'Squeal with Delight'

Humans have certainly been known to let out a squeal or two when experiencing unique joy. Turns out, some marine mammals do the exact same thing. 

Whales and dolphins, alike, let out squeals of joy when they're in a good mood, according to recent findings published in the Journal of Experimental Biology. Lead study author Sam Ridgway, president of the American National Marine Mammal Foundation, has spent over 50 years studying the buzzing and squeaks made by these creatures. He observed the cetacean family, including whales, dolphins and porpoises throughout his studies, noticing that every time these guys let out a squeal, his wife would present them with a food reward.

To study the sounds further, trainers worked with captive dolphins and belugas (a type of whale) to let them know they would be rewarded by the sound of a buzz or whistle. Even when there was no food, the mammals would still squeal just in response to the sound.

"The [squealing] behavior had transferred over to another stimulus that wasn't food," Ridgway said in a news release.

Researchers believe their latest findings reiterate those from the 1950s when animals appeared to feel the same amount of pleasure from electrical stimulation of a region of the brain that released dopamine--a neurotransmitter associated with pleasurable feelings--when receiving rewards.

Further analysis revealed that the whales and dolphins did, indeed, express their happiness through their boisterous squeals.

"The dolphins take an average of 151 ms extra time for this release, and with the belugas...it's about 250 ms delay," Ridgway concluded. "We think we have demonstrated that it [the victory squeal] has emotional content."