Spreading emotions between parrots

In the same way that laughter in primates (including humans) and rodents is spread from one individual to another, play vocalizations may also act as positive emotional contagions.

Kea parrots (Nestor notabilis), for instance, are known to exhibit complex play behavior and emit peculiar play vocalizations – so-called warble calls.

To investigate whether these sounds could act as a positive emotional contagion, the authors used acoustic playback in a trial lasting for 15 minutes: 5 minutes of playback experiments and the other 10 minutes divided equally in two pre- and post-periods.

In addition to the play call, two other types of non-play Kea call, the call of another bird and a standardized tone were played. Behaviors were observed and scored based on the social interactions and play that resulted.

The play calls seemed to result in a higher frequency and longer duration of play when compared with the other sounds played. It was also observed that the birds preferred to start playing with non-playing birds or with an object than join a bird that was already playing. This suggests a higher probability that these playing calls are not an invitation to play with another bird but do act as a positive emotional contagion.

The authors hypothesize that, in contrast to what happens with wolves and bonobos, where social play behavior is rare in mature animals of opposite sex, social play between male and female Kea parrot adults is spontaneous and occurs in the same circumstances as play in juveniles.

Schwing R et al. Positive emotional contagion in a New Zealand parrot. Current Biology 27, R199–R217, March 20, 2017. http://dx.doi.org/10.1016/j.cub.2017.02.020