London Zoo penguins die in malaria outbreak
Six penguins have died following an outbreak of malaria at London Zoo.
The birds contracted the avian strain of the disease from mosquitoes and died in August.
Zookeepers had increased the birds' anti-malaria medication due to fears that the wet weather would let the insects thrive.
Avian malaria cannot be passed on to humans, nor can it be passed from bird to bird, and the zoo says the remaining penguins are "healthy and well".
A spokeswoman for London Zoo said avian malaria is "endemic" in the UK's wild bird population.
Preventative measures, including anti-malaria medicine were in place on a daily basis to prevent this "very sad occasion" from happening again, she added.
Avian malaria in penguins is not uncommon and outbreaks have been recorded as far back as the 1920s, according to Dr Stephen Larcombe, who studies the disease at Oxford University's Edward Grey Institute.
He said: "Generally where they live is cold and windy so they don't get infected very often in their native conditions.
"In zoos it is quite likely that mosquitoes will be around, especially when, like this year, conditions are wet and there's lots of things for them to bite.
"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.
"Once one penguin is infected it becomes a sort of reservoir for the parasite."