Only two Adelie penguin chicks have survived the Antarctic breeding season, in a catastrophic year for the birds.

Scientists say unusually extensive sea ice hung around late into the summer, meaning the penguins had to travel further for food.

Shannon Morris is a penguin caregiver at the International Antarctic Centre in Christchurch.

She said they're some of the hardiest creatures on Earth, but this breeding season has simply been too tough.

"Out of over 20,000 pair of breeding birds, only two chicks have survived this season."

Morris said it has been devastating.

"The babies are sitting waiting, they are freezing and they are starving to death. It happened four years ago too I believe."