Thousands of miles from the battles over climate change—from politicians’ charges and countercharges, from legal disputes, from multimillion-dollar corporate-ad campaigns—David G. Ainley counts penguins.
Why? It’s not because they’re cute—although recent films like the animated Happy Feet series have made clear the power of the little waddlers to grab public attention. No, Mr. Ainley is here counting flightless birds because researchers have a 50-year record of direct observations of Adélie penguins that is invaluable to climate scientists. And Antarctica’s cold, dry climate has preserved far more information in the form of high-quality fossils going back some 35,000 years—including fossils from the period of warming after the last ice age, 12,000 years ago.
Antarctica has seen some recent declines in penguin populations, says Mr. Ainley, an adjunct professor of marine ecology with the Moss Landing Marine Laboratories, a project of seven California State University campuses. But he adds that some penguin colonies are growing, at times substantially—and the population fluctuations don’t always result from climate shifts.
At Ross Island’s Cape Crozier, which Mr. Ainley visited last month, one of the world’s largest colonies of Adélie penguins has seen a surge, reaching 263,000 breeding pairs. At Cape Royds, a few miles across the wind-swept island, a multiyear decline appears to have hit bottom.
“Many young birds visited this season,” signaling a coming jump in the Cape Royds breeding population, says Mr. Ainley, who also works for H.T. Harvey and Associates, which helps educate schoolchildren about the environment.
After a decade of growth at Cape Royds, the Adélies reached about 4,100 breeding pairs in 2001, Mr. Ainley says. Then the numbers fell to about 1,800 pairs while sea ice was trapped in McMurdo Sound from 2001 to 2005, forcing the penguins to walk about 45 miles to get food from the ocean.
“Since they are never happy about that,” he says of the long walks, “very few chicks were produced during those years.” Now, with the ice gone, the colony at Cape Royds is producing “bumper crops.”
The climate shifts affecting penguins can vary across the continent, often as a result of fluctuations in ocean temperatures that may ultimately be driven by global climate change, Mr. Ainley says. There are other factors at work, too: The Adélie population at Cape Crozier may have been boosted lately because industrial-scale fishing has been removing a primary competitor, the Antarctic toothfish.
Either way, the Adélies aren’t faring nearly as well on the other side of Antarctica, along the peninsula nearest South America, says Jean Pennycook, a former chemistry instructor at California State University at Fresno who just spent two and a half months camping among the colonies there.
The disappearance of sea ice plays a key role in the area. Two species of penguins, the chinstraps and the Gentoos, are thriving because they prefer the more open ocean environment, says Ms. Pennycook, who is now a grade-school science teacher who comes to Antarctica on National Science Foundation study grants. “Those two species have come in like gangbusters,” with increases approaching 100-fold, she says. But the Adélies, small birds that need ice edges and floes to help them enter the water, “have virtually disappeared.”
If you don’t count the logistical complications of getting to Antarctica, penguins are relatively easy to study, Ms. Pennycook says. Just a few weeks after baby chicks are born, the parents leave in pursuit of food. The researchers then move in, corral the babies inside some fencing, and attach identification bands to their wings. That allows the scientists to follow their movements years later.
Camping among the penguins on the Antarctic coastline means months of no running water, no television, no fresh food. “But I wouldn’t trade one of those days for any day anywhere else,” Ms. Pennycook says. “It’s fantastically beautiful to be part of the lives of the Adélies.”
