Pesto penguin molts. Here’s what’s next for this icon

“Moulting is very (energetically) expensive,” says Truczki. “They need to use most of their fat reservoir, the subcutaneous layer of skin, all the energy they stored up before to grow new feathers. It’s a big change for a little chick.”

He expects Pesto to lose weight quickly over the next three weeks as he works hard to grow his adult feathers, as well as the adult muscles he will need to both swim and fend for himself.

Does Pesto show signs of penguin evolution?

King penguins are often confused with emperor penguinsbut in fact are their ancestors. A million years ago The king penguin population headed south and began to evolve into their larger relatives, the emperor penguins. Emperor penguins are among the hardiest and most cold-adapted animals on the planet, breeding on Antarctic sea ice in the depths of winter’s darkness.

To survive, they developed a defense against the cold: their body temperature increased and they became taller and rounder, reducing their volume-to-surface ratio to lose less body heat. (This is why they can’t be kept effectively in captivity, says Wienecke. Unlike kings, who can comfortably hang out in refrigerated dwellings ranging from 32 to 50 degrees Fahrenheit, emperors’ homes will have to be expensively maintained below freezing.)

“At some point, many of these adaptations must have emerged, and this may be due to what we call persistent genetic variations,” Truczki explains. “These variations could be present in the ancestral king penguin population, or they could be the result of new mutations arising by chance and then being selected for.”