Longest egg incubation for a penguin

Native to the sea-ice off Antarctica, the emperor penguin (Aptenodytes forsteri) – the world's largest living species of penguin – incubates its single egg for between 62–67 days, with an average incubation period of 64 days. The egg incubation period for most other penguins is approximately 35–40 days.

Along with the king penguin (Aptenodytes patagonicus), emperor penguins lay just a single egg annually – the fewest eggs laid by a penguin per year.

Interestingly, the emperor penguin is unique in that it is the only penguin species in which the males have the sole responsibility of incubating the egg. In all other penguin species, the males and females take turns incubating their egg(s). Once a female emperor penguin lays her single egg and transfers it to the feet of her partner, she heads for the ocean, where she spends the next two months foraging for food. The males are left on their own to care for the egg for 62–67 days. They incubate the egg on top of their feet under a brood pouch, and huddle closely together for warmth (the only penguin species to exhibit this type of huddling behaviour). They cannot go to sea to eat while incubating their egg, so they must fast during this time (and during the courtship and mating phase); one male emperor endured a 134-day fast – the longest time without food for a bird.

Emperor penguins are also the only penguin species that reproduces during the harsh Antarctic winter, during which they must cope with lows of -40 degrees Celsius (-40 degrees Fahrenheit) – the lowest temperatures endured by a bird.