Laura Erickson's For the Birds

Penguins This week I’m honoring Roger Tory Peterson, and I thought it would be fitting to make the final program about his favorite birds of all, penguins. Peterson often talked about how birds can fly whenever and wherever they want, and that this ability makes them the most vivid representations of life itself. But as he got older and spent more time with them, he was more and more drawn to penguins. Why? As he told a Chicago Tribune reporter in 1986, “Others see little clowns, ridiculous dwarfs, little people dressed in feathers. But they are far from that. They are highly specialized birds dedicated to penguinism, a life molded by the cold, impersonal sea, harsh climate and the crowded colonies in which they reproduce.” Peterson was taken with all penguins, but especially loved the ones who survived in the harshest environments. Peterson died in 1996, probably without fearing too much for the survival of penguins. But life is changing in the southern hemisphere. In March 2000, the world’s largest iceberg, B-15, broke off the Ross Ice Shelf in Antarctica. It was larger than the island of Jamaica. It drifted westward toward the much smaller Ross Island, which is the site of the southernmost open water on our planet. By the time B-15 reached the island it had broken apart, but the three main pieces were huge. A 100-mile-long fragment ground to a halt in the shallows off Ross’s easternmost point, Cape Crozier. Typical ocean currents were diverted, and Ross Island froze into the ice for the next five years straight. My friend and colleague Hugh Powell, science writer at the Cornell Lab of Ornithology, who spent some time in Antarctica, has been following penguins at recent scientific meetings, and wrote on Cornell’s blog yesterday about a population of Adelie Penguins that breeds on Ross Island. Such a huge iceberg blocking their path to their colonies might have sent lesser penguins elsewhere. But most of the 400,000 Adelie penguins persevered, some trekking across more than 40 miles of ice to reach the most distant nesting colonies on Cape Royds. With such an unexpectedly long journey, few successfully raised young, but when the iceberg and surrounding sea ice cleared in 2006, Hugh says that they found themselves with more krill and fish than they could eat. And hardly any predators (such as South Polar Skuas and leopard seals) took the trouble to raid such a small group. Nest success improved, and the colony started to grow and thrive again. Hugh notes that in general, times are good for Adelie Penguins on Ross Island, where the climate isn’t changing nearly as quickly as it is on the Antarctic Peninsula, halfway around Antarctica and 1,000 miles farther north. There, rapid warming seems to be proving too much for Adelie Penguins. Their colonies are shrinking as northern relatives called Chinstrap Penguins move in and crowd them out. But one scientist who’s been studying them described chinstraps as “scared of sea ice.” So for the time being, the Adelies on Ross Island seem safe even as Chinstraps take advantage of warming conditions to increase and multiply. Roger Tory Peterson spent many decades fighting what seemed like hopeless battles, to ban DDT and regulate other pesticides and to protect fragile ecosystems. Hugh advocates for nature the way Peterson once did, and writes “Let’s all hope for (and work toward) a world that stays cold enough for both species to thrive.” Roger Tory Peterson would say amen. There’s a link to Hugh’s blog on my own blog, and linked to www.lauraerickson.com