Thirteen penguins enjoying the winter snowfall at a zoo in Germany have fallen victim to a wild fox who broke into their enclosure at night.
The penguins were killed in a 'bloody frenzy' according to officials of the Euregio Zoo in the city of Aachen.
A spokesman said keepers found the 13 blood-stained bodies lying in the snow yesterday.
'It seems a fox bit his way through the nylon netting surrounding their enclosure to do his work,' he said.
The zoo admitted the nylon netting, which covered up one side of the otherwise bricked-up enclosure, was 'with hindsight, not the smartest thing to have had.'
Zoo boss Wolfram Graf Rudolf, 47, said: 'The fox jumped over a short wall and then bit through the nylon netting to get to the penguins - all Black Footed penguins from the west coast of Africa.'
Among the victims were birds Nena and Adi that Mr Rudolf had personally raised as well as another known as Captain Hook that had lived at the zoo for 24 years.
Penguins are intensely loyal creatures and the survivors are suffering shock and deep trauma at the loss of their partners.
Mr Rudolf added: 'They were the heart of the zoo and part of a valuable breeding programme - every animal was genetically unique. The remaining penguins are traumatised - especially those that have lost partners.'
The fox, identified by prints in the snow, was not found but it will get a shock if it returns after a high voltage cable was put around the penguin enclosure.