World's Biggest King Penguin Colony Shrinks 90%

The planet's largest colony of king penguins has declined by nearly 90% in three decades, alarmed researchers said on Monday.

The last time scientists set foot on France's remote Ile aux Cochons—roughly half way between the tip of Africa and Antarctica—the island was blanketed by two million of the flightless birds.

But recent satellite images and photos taken from helicopters show the population has collapsed, with barely 200,000 remaining, according to a study published in Antarctic Science, AFP reported.

Why the colony on Ile aux Cochon has been so decimated remains a mystery.

Climate change may play a role.

In 1997, a particularly strong El Nino weather event warmed the southern Indian Ocean, temporarily pushing the fish and squid on which king penguins depend south, beyond their foraging range.

Other factors may be contributing to the decline of the Ile aux Cochon colony, including overcrowding.

"The larger the population, the fiercer the competition between individuals," noted a statement from France's National Centre for Scientific Research, which funded the study.

"The repercussions of lack of food are thus amplified and can trigger an unprecedented rapid and drastic drop in numbers."

Another possible culprit is avian cholera, which has affected seabirds on nearby Marion and Amsterdam Islands, including some king penguins.

It is also possible that invasive species such as rats, mice or cats, have found their way onto the island.

But until Weimerskirch and other researchers return to Ile aux Cochons—hopefully, he said, in early 2019—they will not know for sure.

The Red List of Threatened Species conservation status for king penguins is currently "least concern", but the new data may prompt a reevaluation.