The last time scientists visited Ile aux Cochons in 1982, an island that is part of an archipelago in the southern Indian Ocean, the king penguin population was booming. Over 500,000 breeding pairs (around 2 million penguins total) huddled together there, making the island the largest king penguin colony in the world. But new research shows their numbers have been on a stiff decline since then—by as much as 88 percent.
“The rate of decline is unbelievable,” Henri Weimerskirch, study author and ecologist at the University of La Rochelle in France, told Gizmodo via email.
Dee Boersma, a UW Biology Professor who was not involved with this study, told Gizmodo she wasn’t fully convinced by the new population estimates.
“The problem is, they cite varying methods from the 1960s to the 1980s to 2017,” she said, referencing how measurements from helicopters vs. satellites can be very different, and also that measurements were taken from many different months out of the year. “It’s really difficult to know just how much the penguins have declined.”
Still, she said the evidence is overwhelming that the colony is shrinking overall. And king penguin populations on other islands in the archipelago have stayed more or less stable, which makes this particular decline both alarming and puzzling.
Identifying precisely what’s going on matters not just for king penguins, which are listed as “least concern” on the IUCN Red List of Threatened Species, but also for other, more vulnerable penguins. Understanding threats to penguins in remote locations, Boersma said, is critical—penguin declines are often a sign that something funky is going on with the environment there.
“Penguins are ecosystem sentinels that can tell us about how the environment is changing,” she told Gizmodo. “We need to be paying more attention to them.”
Read the entire article on Gizmodo.