(ANIMAL SCIENCE) Researchers have found that wind speeds over Antarctic seas are increasing—making life a bit easier for local albatrosses. Increased wind speeds help sea birds make shorter foraging trips and, as a result, the local birds have grown in size. Could too strong of winds become problematic? Read on to learn more. — Global Animal
New York Times, Sindya Bhanoo
Wind speeds over the Southern Ocean, near Antarctica, are increasing, and that has made life a little easier for wandering albatrosses.
The birds, which depend on wind currents to stay aloft as they fly, are able to make shorter foraging trips and, as a result, have grown in size. Researchers from the Chizé Center for Biological Studies in France report these findings in the current issue of the journal Science.
“The increase in the wind speed is a general phenomenon over all the oceans, but in the Southern Ocean it is more marked,” said Henri Weimerskirch, a seabird ecologist at the center who, with his colleagues, analyzed 40 years of data on albatrosses in the Crozet Islands.
After laying eggs, the birds take turns going out to forage for food. “When one partner is incubating the egg, the other partner is out at sea,” forcing the incubating bird to fast, Dr. Weimerskirch said.
Over the years, as wind speed has increased, birds have slowly reduced their foraging time, to 9.7 days in 2008 from 12.4 days in 1970.
This in turn has reduced fasting time, and both males and females have, on average, increased in mass by a kilogram, about 2.2 pounds, over the years.
“This result shows that this change in wind pattern has been very favorable,” Dr. Weimerskirch said.
But that could change if the wind speed increases too much.
The birds’ travel and flight speeds do not have a linear relationship to wind speed, and too strong a wind could be problematic, the authors say.
Although it is not known exactly why wind speeds are increasing, scientists theorize that the change is connected to climate change. Dr. Weimerskirch noted that some studies suggest the ozone hole over Antarctica is involved.
More New York Times: http://www.nytimes.com/2012/01/17/science/