The bizarre behaviour of the baboons in Emmen zoo has come in for a lot of media attention over the past few days, with the Volkskrant and Parool both carrying pictures of the troubled tribe.

The group – 120 animals-strong – appear to be suffering from an attack of mass hysteria and has withdrawn to a corner of the compound. There, the animals sit on the rocks or in the trees staring into the same direction and refusing to move – even for a banana.
‘They have probably heard something – a high-pitched tone or a vibration – which caused them to panic,’ baffled keepers told the TV news. ‘It is typical baboon behaviour,’ said David van Gennip of ape rescue foundation AAP in the Volkskrant.
‘They can panic if they see their reflection in water. If the leader signals the alarm, the rest all follow.’ The Emmen tribe has shown similar behaviour in 1994 and 1997. Both times the hysteria faded after four days.