Rätsel um Paviane in niederländischem Zoo

© APA/VINCENT JANNINKepa03808474 A group of hamadryas baboons sit in a tree in their enclosure at Emmen Zoo in Emmen, the Netherlands, 31 July 2013. Emmen zoo's baboons behave strangely as they do not eat and sit close together looking at trees and a small corner of their island. The cares have no explanation for their behaviour. A few years back the same group of baboons showed the similar behavior of mass apathy. EPA/VINCENT JANNINK