By Jessica Zhou ’22
People laugh when they are happy, and laughter infects others. Coincidentally, carnivorous parrots from New Zealand also have infectious “laughter”, which can be called “play call.”
Happy laughter is contagious, and this phenomenon may not only exist in humans. An article in Current Biology suggests that a “playing call” from New Zealand’s kea parrot (Nestor notabilis) also has similar appeal when they are happy. Earlier studies also found that chimpanzees and rats have similar vocalizations. However, The kea parrot from New Zealand are found to be the first non-mammal having such emotionally contagious vocalization.
Raoul Schwing of the Messerli Research Institute in Austria, who deeply interested in this research, studied all the sound commands of the kea. The results of the study shows that there is a clear correlation between the play behavior of the birds and their play call.
“We used acoustic playback to investigate the effect of play calls on wild kea, finding that play vocalizations increase the amount of play among both juveniles and adults, likely by acting as a positive emotional contagion,” Schwing demonstrated.
Accordingly, the recording ‘laughter’ of the happy wild kea to make the normal mood individuals active. When these adult kea heard the recording, even if there are not such individuals who can play together, they will play spontaneously. Accordingly, the calls will have emotional influence on birds that heard it and give them a playful state, which is similar to human laughter.
To study this phenomenon, they played a five-minute play summoning recording of the wild kea. At the same time, they also played 4 sounds, including two other types of kea calls, a call of the South Island robin (Petroica australis australis), and a standardized tone as a control. The results showed that compared to the controlled group, the wild kea played longer and more vigorously after hearing the calls.
While the play calls of kea can be compared to their own contagious laughter, which is indeed anthropomorphic, it does have a similar effect. The researchers are planning to study more about the effects of play call and the playing behavior in kea’s social groups as well. However, for the public, it becomes an interesting understanding – birds laugh, and they infect each other! It seems that they are not different from us.
