This video is called Science Bulletins: Whales Give Dolphins a Lift.
From Science News:
Dolphins and whales may squeal with pleasure too
by Science News Staff
8:00am, August 15, 2014
Guest post by Chris Riotta
When dolphins and whales squeal, they may not be sending food signals to their friends. They could just be shrieking with pleasure.
After measuring the time delay between a dolphin or whale receiving a reward and the animal’s squeal, one researcher noticed the lags were about as long as the time it takes for the chemical dopamine to be released in the brain. Dopamine helps control the brain’s reward and pleasure centers.
Because the time it takes for the animals to squeal is about the same as for a release of dopamine, the dolphins and whales may be making these sounds of out sheer delight, scientists argue August 15 in the Journal of Experimental Biology.