Six penguins die of malaria
A malaria outbreak at London Zoo in August caused six penguins to die.
The birds contracted an avian strain of the disease from mosquitos, despite zookeepers increasing their anti-malaria medication. It was feared that the warm, wet weather of this summer would cause the insects to thrive.
Humans cannot contract avian malaria, nor can birds pass it on to one another, so the zoo says its remaining penguins are "healthy and well".
Outbreaks of avian malaria have been recorded as far back as the 1920s, and the disease is endemic in the UK's wild bird population, however, the zoo said they administered anti-malaria medication on a daily basis to try to prevent this "very sad occasion".
Dr Stephen Larcombe, who studied the disease at Oxford University's Edward Grey Institute, said: "Generally where [penguins] live is cold and windy so they don't get infected very often in their native conditions.
"In zoos it is quite likely that mosquitos will be around, especially when, like this year, conditions are wet and there's lots of things for them to bite."
He added: "Because penguins will have almost no resistance, when one bird does become infected it will probably have a lot of parasites in its blood which makes it far more likely for other penguins to become infected."