Considered some of the most iconic Antarctic mainstays, chinstrap penguins have spent millennia adapting to the world’s southern pole. Standing just a couple feet tall, the blubbery birds are accomplished hunters at sea and expert mountaineers on the icy terrain. Evolution has tailored them exquisitely to their surroundings—and even the slightest changes can imperil their livelihood.
Chinstrap penguins, then, serve as a sort of ecosystem barometer: Their suffering is a litmus test for troubles to come.
“This shows something in the marine ecology is broken, or has drastically changed since the 1970s,” Strycker tells Jonathan Watts at the Guardian.
Strycker and his colleagues conducted the census as a part of an Antarctic Greenpeace expedition that ran from January 5 to February 8, deploying drones and handheld clickers to tabulate the number of chinstrap breeding pairs along the frigid continent’s northwest. All 32 colonies surveyed on Elephant Island—a famous chinstrap outpost—had dwindled, yielding a nearly 60 percent drop in the island’s total population compared to 1971, when more than 100,000 breeding pairs roamed its shores.
A likely driver of the birds’ issues is the alarming disappearance of their primary prey source, krill. These tiny crustaceans have decreased by as much as 80 percent in some Antarctic seas, reports Jason Bittel for National Geographic. Though scientists are still sussing out the factors killing the krill, warming waters and ocean acidification both likely play a role. These declines don’t just hurt chinstraps: As a key player in countless food chains, krill sustain many other species as well, including fish, seals and whales.
https://www.smithsonianmag.com/smart-news/preliminary-census-documents-antarcticas-chinstrap-penguins-sharp-decline-180974181