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Largest King Penguin Colony in the World Drops by 90%


Trilobites

Researchers hadn’t visited the remote island in 30 years when there were 500,000 breeding pairs. Satellite images now indicate perhaps as few as 60,000 pairs.

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The colony of king penguins on the Île aux Cochons, or Pig Island, in 1982, when researchers last counted its population.CreditHenri Weimerskirch

After three decades out of the public eye, a giant colony of king penguins has lost 90 percent of its population, according to a new study.

The colony of 500,000 breeding pairs, long considered the largest of king penguins in the world, lived on the Île aux Cochons (or, less elegantly, Pig Island), a French territory in the Crozet archipelago in the southern Indian Ocean between South Africa and Antarctica.

But the penguins haven’t been counted in person since 1982 when researchers last visited. In late 2016, researchers flew over it by helicopter and saw noticeably fewer penguins than expected.

Since then, by closely examining three decades of satellite images, researchers have concluded that there are just 60,000 breeding pairs left on the island.

“It was really a surprise for us,” said Henri Weimerskirch, a co-author on the new paper, published in Antarctic Science, and a member of the research teams in 1982 and 2016. “It’s really very depressing.”

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The research team suspects that climate change could be playing a role, as it has with other colonies of penguins in parts of Antarctica. But competition for resources, diseases and relocation may possibly have contributed to population losses.

Researchers plan to do a head count on the island but they can’t get there until late fall 2019 at the earliest, because of the cost and timing issues, said Dr. Weimerskirch, research director of the Chizé Centre for Biological Studies at the French National Centre for Scientific Research. A protected nature preserve, Pig Island isn’t easy to reach, and the animals can’t be seen from the water, because the colony is situated inland, he said.

If the count from the satellite images proves accurate, it would significantly reduce the global population of king penguins, estimated at 1.5 million to 1.7 million breeding pairs worldwide with this loss. They had not been considered endangered before, but might be, Dr. Weimerskirch said.

King penguins are second-largest in population after emperor penguins. They don’t nest, but lay one egg and parents take turns incubating the egg with an abdominal layer called a brood patch for two months. King penguins leave their young and swim south to forage for fish and squid in the waters of the Antarctic polar front, where cold, deep water mixes with more temperate seas. If they can’t reach this polar front and can’t swim back within about a week, their chicks will starve to death.

The colony viewed from a helicopter in December 2016, when researchers noticed far fewer penguins than expected.CreditPeter Ryan


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