torsdag 22 maj 2014

Two new publications on raven play!

In May's issue of Animal Behaviour and Cognition, we have contributed with no less than two papers - both on raven play.

"An exploration of Play Behaviours in Raven Nestlings" (Osvath, Osvath & Båth) is study of the nestlings from last year, where we analyzed almost 20 hours of nest activity - discovering that the chicks actually spent equal or more time playing in the nest than on maintenance behaviors and flight training.

"Sub-adult Ravens Sunchronize their play: A Case of Emotional Contagion" (Osvath & Sima) is a study on the sub-adult ravens which explored instances of contagious behaviors within the play domain.The results indicate emotional contagion: the birds engaged in all categories of play on a higher level under the condition where contagion was likely to occur. This type of contagion is thought of as a key phenomena in the development of advanced social cognition in humans. This is the first time ever it has been shown in birds.


Empty nest

In the end, the number of nestlings turned out to be four, and after weeks and weeks of feeding them in the nest it was finally time to fledge!

The first chick, presumably a female, fledged on May 15th and the second chick, which we think is a male, one day later.The last two nestlings seemed almost surprised, watching the comotion on the ground from above. But two days later, on May 18th,  they decided it was time to go.
After the incident last year when the unexperienced parents pulled out several tail feathers when trying to drag the first fledglings back to the nest, we feared that something similar would happen this year. But although a bit distressed when the chicks are too spread out in the aviary, Siden seems to have learnt from last year. Still, he sometimes tries to drag or pull his young to areas he consider"safe" - but all feathers are intact.

When Siden has a say, all four chicks sits safely in the dead old elder tree, which serves as a perfect playpen to new-fledged ravens.