Saturday, January 21, 2012

Climate Change Makes Faster Birds

While debate continues about the causes of climate change, the fact is: the climate IS changing. And as it does, we're seeing other changes around us.
Wind speeds over the Southern Ocean have been increasing over the past three decades and those stronger winds are making seabirds stronger and faster. Wandering albatrosses are benefiting from the changes, with shorter trips, improved breeding, and weight gain.
The wind speed shift is linked to climate change, in a study published in the latest issue of Science.
Scientists studied the wandering albatross, which spends most of its life in flight, touching down on land mostly just to find food or to breed. But they believe other birds like petrels have been affected by the wind changes too.
The team analysed 40 year's worth of information on an albatross population on the Crozet Islands, a sub-antarctic group of small islands in the southern Indian Ocean. For decades, researchers have monitored the birds' feeding and breeding, and in 1989 they began outfitting the birds with satellite transmitters to track their travels.
The researchers found that Southern Ocean westerlies increased by 15% over the past few decades. Both female and male flight speeds got a boost as a result, with females alone traveling about 311 miles per day in 1990, but about 435 miles per day as of 2010. Easier flights have improved their breeding success, allowing them to grow larger. The weight gain may be an adjustment to the speedier winds, allowing the birds to experience greater wing loading while in flight.
The winds are also gradually moving towards Antarctica: all animals in the region, from birds to their prey, are likely to have been affected. It's predicted wind strength will continue to increase, and that the poleward shift will continue. 
At present albatrosses are under constant threat from longline tuna fisheries, which have indirectly killed as many as 300,000 per year! Of  22 albatross species worldwide, 17 are classified as threatened.

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