Viernes, 17 Noviembre, 2017

Playful New Zealand parrots have 'contagious laughter' too

For this New Zealand parrot'laughter is contagious Two juvenile kea tussle playing on the ground. Credit Raoul Schwing
Ramiro Mantilla | 21 Marcha, 2017, 00:21

A new study has found that the kea parrot has a powerful "play call" that can put others in the mood to play as well.

Kea, the world's only alpine parrot, have a range of calls, but one, in particular, appears to be used in connection with the bird's complex play behavior. To show whether actual emotions are triggered in keas by the "laughter" you would have to "find some way of measuring the emotional state of both the callers and listeners". Many birds began playing with their more serious compatriots, while others began playing with objects, or started performing aerobatics in the air, according to a study published today in Current Biology.

The average number of play bouts per bird monitored was 20 times higher during those periods than when birds heard the other recordings.

Wild keas - a large parrot species from New Zealand - engaged in playful behavior when researchers played recordings of kea play calls on speakers.

"The fact that at least some of these birds started playing spontaneously when no other birds had been playing suggests that similar to human laughter, it had an emotional effect on the birds that heard it, putting them in a playful state", study co-author Raoul Schwing of the Messerli Research Institute in Austria said in a statement.

Raoul Schwing of the University of Veterinary Medicine in Vienna, Austria, and his team played 5-minute recordings to gatherings of between two and a dozen wild keas on a mountainside of New Zealand's Arthur's Pass National Park, on the southern island.

To carry out their investigation, the scientists recorded the sound and played it back to wild birds at Arthur's Pass National Park, on New Zealand's South Island. Instead, they concluded that it induces playfulness due to its acting as a positive emotional contagion. This, in turn, could promote tolerance and sync up moods when an individual is interacting with others. Scientists know that play vocalization in some species can act as a form of emotional contagion. Playful animals are usually inattentive, so emitting sounds would draw even more attention to them at a time when they are already vulnerable to predators. This could help to explain why they evolved their own form of laughter.

Emotionally contagious sounds are not always happy ones, though. "Alarm calls and aggressive growls, for example, seem to have an emotionally contagious effect on the receiver".

Contagious "laughter" has also been reported in non-human primates, such as chimpanzees, and rodents. He noted that people might tear up watching others cry, or while listening to sad music at a movie. The scientists hypothesized that these play calls could act like laughter in humans, spreading from one bird to the next and eliciting play.

Moving forward, the researchers plan to investigate the effects further to determine how play and play calls influence kea social groups.