Deputy zoo director Helmut Mägdefrau on Thursday said the birds couldn’t cope with the deep freeze that has gripped much of Germany for the past few weeks.
He said Humboldt and Jackass penguins – indigenous to South America and South Africa – perished after the cold weakened their immune systems, which made them susceptible to illness.
“Both types of penguins can handle zero degrees, but twelve degrees below zero is problematic for them,” Mägdefrau said.
The zoo’s surviving 40 penguins have been moved indoors, where they can huddle next to heat lamps.