Emperor Penguin

Aptenodytes forsteri

Emperor Penguin (Aptenodytes forsteri) is a species in the genus Aptenodytes, family Spheniscidae, order Sphenisciformes.

Scientific classification

Description

The emperor penguin is the tallest and heaviest living penguin, standing about 1.15 metres and weighing 22–45 kilograms depending on the stage of the breeding cycle. The plumage is dense — around 100 feathers per square centimetre — and layered over a thick fat store.

Breeding

Emperors are the only bird that breeds through the Antarctic winter, on sea ice, away from land. The female lays a single egg and transfers it to the male, who balances it on his feet beneath a brood pouch and incubates it for about 65 days in darkness and temperatures reaching −40 °C with gale-force winds, fasting throughout and losing a large fraction of his body mass.

Males survive this by huddling in tightly packed groups that rotate slowly, so that individuals take turns on the cold windward edge. The huddle is a genuinely collective solution: no bird could survive the winter alone.

The female returns after feeding at sea to take over the chick, and the pair then alternate.

Diving

Emperors are the deepest-diving birds. Recorded dives exceed 500 metres and 20 minutes, supported by high myoglobin concentrations, tolerance of large oxygen debts, and the ability to shut down circulation to non-essential tissue.

Conservation

Near Threatened. The species depends on stable fast ice for the full length of a breeding cycle; colonies have failed completely in years when the ice broke out early, and projections of Antarctic sea-ice loss make this the dominant long-term concern.

References

• BirdLife International (2020). Aptenodytes forsteri. IUCN Red List assessment 22697752.
• Ancel, A. et al. (2015). Emperor penguin mates: keeping together in the crowd. *Proceedings of the

Royal Society B* 282.