Whales and dolphins 'squeal with delight like children', researchers claim

Scientists previously thought the sounds were communication or trained

Dolphins and whales squeal with delight “like children” when they are having fun, scientists have claimed.

Buzzing and squeaks have long been observed when captive animals are rewarded with food, as well as among wild animals, but were dismissed as a result of training or communication signals.

But new research, published in the Journal of Experimental Biology on Wednesday, suggests marine mammals make noises to express delight.

Sam Ridgway, president of the American National Marine Mammal Foundation, has observed the cetacean family, including whales, dolphins and porpoises, for decades.

Noticing they squealed every time they were rewarded with fish, his wife Jeanette suggested they reminded her of “delighted children” and he started to research why the noises were made.

Trainers working with captive dolphins and belugas let them know they will be rewarded with food with a buzz or whistle.

But Mr Ridgway noticed even when there was no food, the mammals would squeal in response to the sound associated with it.

Then even when there was no “reward” sound when they had completed a task like a deep dive, the dolphins and beluga whales would still squeal as if in a victory sign.

“The behaviour had transferred over to another stimulus that wasn't food,” he said.

As part of the study in San Diego Bay, California, two rescued belugas and a dolphin raised in captivity were trained to dive into the open ocean and turn off an artificial buzzer by pressing a button while underwater microphones recorded the sounds.

While still underwater, the animals made victory squeals right after they turned off the buzzer, well before coming up to the surface.

When mammals, including humans, get a reward, the chemical dopamine floods to the brain's pleasure centres.

It makes evolutionary sense for this to coincide with food to aid survival, Mr Ridgway said, but without food suggests pure enjoyment.

The researchers measured the time when the dolphins and whales in the study made their victory squeals and found that dolphins squealed 151 milliseconds after the reward signal and belugas did so 250 milliseconds later, suggesting it was in response to a dopamine surge.

As dopamine release takes between 100 and 200 milliseconds, Mr Ridgway realised that the animals could be expressing pleasure.

He is using the research to look into the cognitive abilities of cetaceans in greater depth. 

“We think we have demonstrated that it [the victory squeal] has emotional content,” he said.

Start your day with The Independent, sign up for daily news emails
News
ebooksAn unforgettable anthology of contemporary reportage
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

MBDA UK Ltd: Mission Planning and Control Solutions Systems Engineer

Competitive salary & benefits: MBDA UK Ltd: What’s the opportunity? A pro-act...

MBDA UK Ltd: System Design Capability

Competitive salary & benefits: MBDA UK Ltd: What’s the opportunity? The small...

Recruitment Genius: Production / Manufacturing Operative

Negotiable: Recruitment Genius: This leading garage door manufacturer are curr...

Recruitment Genius: Graduate Software / Solution Sales

Negotiable: Recruitment Genius: This is an exciting opportunity to join a thri...

Day In a Page

Sepp Blatter resignation: The beginning of Fifa's long road to reform?

Does Blatter's departure mean Fifa will automatically clean up its act?

Don't bet on it, says Tom Peck
Charles Kennedy: The baby of the House who grew into a Lib Dem giant

The baby of the House who grew into a Lib Dem giant

Charles Kennedy was consistently a man of the centre-left, dedicated to social justice, but was also a champion of liberty and an opponent of the nanny-state, says Baroness Williams
Syria civil war: The harrowing testament of a five-year-old victim of this endless conflict

The harrowing testament of a five-year-old victim of Syria's endless civil war

Sahar Qanbar lost her mother and brother as civilians and government soldiers fought side by side after being surrounded by brutal Islamist fighters. Robert Fisk visited her
The future of songwriting: How streaming is changing everything we know about making music

The future of songwriting

How streaming is changing everything we know about making music
William Shemin and Henry Johnson: Jewish and black soldiers receive World War I Medal of Honor amid claims of discrimination

Recognition at long last

Jewish and black soldiers who fought in WWI finally receive medals after claims of discrimination
Beating obesity: The new pacemaker which helps over-eaters

Beating obesity

The new pacemaker which helps over-eaters
9 best women's festival waterproofs

Ready for rain: 9 best women's festival waterproofs

These are the macs to keep your denim dry and your hair frizz-free(ish)
Cycling World Hour Record: Nervous Sir Bradley Wiggins ready for pain as he prepares to go distance

Wiggins worried

Nervous Sir Bradley ready for pain as he prepares to attempt cycling's World Hour Record
Liverpool close in on Milner signing

Liverpool close in on Milner signing

Reds baulk at Christian Benteke £32.5m release clause
On your feet! Spending at least two hours a day standing reduces the risk of heart attacks, cancer and diabetes, according to new research

On your feet!

Spending half the day standing 'reduces risk of heart attacks and cancer'
With scores of surgeries closing, what hope is there for the David Cameron's promise of 5,000 more GPs and a 24/7 NHS?

The big NHS question

Why are there so few new GPs when so many want to study medicine?
Big knickers are back: Thongs ain't what they used to be

Thongs ain't what they used to be

Big knickers are back
Thurston Moore interview

Thurston Moore interview

On living in London, Sonic Youth and musical memoirs
In full bloom

In full bloom

Floral print womenswear
From leading man to Elephant Man, Bradley Cooper is terrific

From leading man to Elephant Man

Bradley Cooper is terrific