Laughter is truly the universal language -- not just among humans, but also among parrots. In a new study published in Current Biology, researchers observed the play behavior of kea parrots and discovered a laughter-like "play call" that's very contagious among the intelligent birds.

According to a report from The Atlantic, the kea parrots' play call is a warbling sound that the birds make when they are playing. Researchers also found that the distinct noise is contagious, motivating playful behavior in other kea parrots within earshot. When the other birds hear the play call, they also begin playing, either with the nearest kea parrot or even by themselves.

Lead author Robin Schwing was drawn to the species because of their remarkable intelligence and curiosity. After developing a library of kea calls and cataloging the different sounds in seven different categories, he realized that one of the kea calls were only used during playtime.

Read Also: Fossil of Tropical Parrot 16 Million Years Ago Discovered in Freezing Siberia

Schwing and his team took the recordings to the mountains to observe the effects of the calls on the birds, discovering that the warbling play call actually made the parrots erupt in playful behavior. As soon as the keas heard the call, a few would immediately join fellow keas who are playing. Others would play with whoever is next to them, while if they're alone, the kea would just begin playing by itself.

Some of the playful behavior include exchanging foot-kicking high fives, performing aerobatic loops, and throwing objects like rocks to each other, according to a report from New Scientist. It's not just the young birds playing either, but adults of both sexes. Then, when the recording stops, the keas also stop playing.

Schwing explained that the emotional contagion caused by the kea's play call is more similar to the way glee-like excitement can spread among young children rather than infectious laughter.

The study said that it's possible that the kea parrot's play call might be akin to the effects of human laughter.

"The only other animals to show this contagion effect are chimpanzees and rats, both very or relatively close in evolutionary terms. Our finding further bridges the perceived gap between humans and [other] animals, and shows that it also happens in birds, which are very distantly related," Schwig said.

Read Also: 61-Year-Old Man Contracts Rare Fatal Pneumonia From His Pet Parrots