With the three brush-tail penguins out of the way (the Gentoo, Chinstrap and Adélie Penguins), it’s time to get a bit bigger. As said in the previous post, the Adélie Penguin is the first of the real Antarctic penguins (the Gentoo and Chinstrap are actually more subantarctic penguins that can be found on the northernmost part of the continent, the Antarctic Peninsula). The other true Antarctic species of penguin is the Emperor Penguin. This is one of the bird species on earth that is the hardest to reach and one that we only seldom see on our regular Antarctic Peninsula trips.
The Emperor Penguin is the largest extant species of penguin. The fossil record shows that much larger penguins have lived in earlier times, with the largest being almost 2m tall and 115kg heavy. Where the Emperor isn’t that big, it’s still a big bird, standing 1.2m tall and weighing up to 45kg. Of all the birds on Earth, the Emperor Penguin has one of the strangest breeding strategies. Not only do they breed near the most inhospitable, windiest, dryest and coldest continent, they also pick the most extreme season to do so: they breed in winter.
Why would a bird choose the coldest and windiest time and place to incubate their egg? Well, being such a large bird, it does take some time for the chicks to get ready for their first winter. They need to be fat, almost adult-size and have a proper set of feathers. This takes about half a year, and the Antarctic summer is short. Besides, they breed on the sea ice, which will melt and break up almost entirely around Antarctica each summer. This means the chicks have to be ready to swim before their platform break up, usually somewhere in January. To make this, they have to start breeding in winter. When the female has laid the egg somewhere in May, she hands it over to the male before she heads out to open ocean where she spends the winter. The males will stay behind on the sea ice, huddling together against the cold. When the single egg hatches, the male only has a milk-like liquid left to feed the chick with. Then they have to wait for the female returns from the ocean, well-fed and with a crop full of squit and fish to feed the chick.
From this point onwards, the male and female take turns caring for the chick and getting food. In the beginning, the distance from the colony to the ocean will be considerable (it’s the end of winter, so the maximum sea ice extent), but soon the ice will start to break up, and the distance will get shorter. Just in time, as the chick will demand more food when it grows larger, so they have to get there quicker. When the chick gets larger, they can keep themselves warm, and both parents can go out to get food for the chick with only a few adults guarding the colony.
When the chicks are old enough, the adults will leave them on the ice and find a place elsewhere to moult. The young Emperors now have to figure out themselves how to get their food and will make their first swims alone, or at least without their parents.
In total there are around 50 colonies (new ones being discovered sometimes by satellite imagery). With climate change threatening the sea ice around Antarctica, projections are of a 19% decrease of Emperor Penguin numbers by the end of this century, though there are a lot of variables uncertain in that estimate. Anyway, it’s one of the most exceptional birds I’ve ever seen.