‘Penguins of the North’ Adjust to Change

Penguins of the NorthThe latest research on little auks, sometimes called “penguins of the north,” reveals a surprising response to a rapidly warming Arctic: The birds make up for food lost to the effects of climate change by catching prey that were stunned by the cold water running off melting glaciers—another effect of climate change

The study, published Monday in the journal Global Change Biology, is the first to examine the feeding habits of little auks as Arctic ice is lost. Scientists watched the birds in Franz-Josef Land, off the northern coast of Russia, during an expedition supported by the National Geographic Society.

Since 2005, the auks’ water has become essentially ice-free in summer, reducing the numbers of tiny animals known as zooplankton, a key food source for the auks. Zooplankton normally congregated around sea ice, but now the birds have shifted to eating zooplankton that are stunned—and thus easier to catch—by cold water running off glaciers melting on land.

The shift hasn’t been entirely seamless. Little auk chicks have been growing just as quickly as they did before 2005, but the adults’ body mass has dropped an average of 4 percent since the early 1990s. That might not sound like much, but “we don’t know what the weight loss is that would really harm them,” says Enric Sala, a co-author of the study and a National Geographic explorer-in-residence.

Why It Matters: Little auks are considered especially vulnerable to climate change. The birds are often considered an indicator species of the Arctic, raising red flags for ecological changes.

“It’s good news that the little auks are adapting now,” Sala says, “but because the system is changing continuously, we don’t know how long they will be able to keep up.”

The birds also play an important role in the Arctic ecosystem, so other species could be affected by changes in little auks.

The Big Picture: To date, the Arctic has warmed twice as fast as lower latitudes have. The Arctic will be essentially free of summer sea ice by the 2030s, with drastic implications for species from seabirds to polar bears, according to the Intergovernmental Panel on Climate Change.

source : http://news.nationalgeographic.com/news/2015/01/150112-little-auks-global-warming-climate-change-environment/

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