A Non-stop Flight fron Alaska to New Zealand |
 Dave Thurlow, Host |
Hi, I'm Dave Thurlow for The Weather Notebook. I recently spoke with author Scott Weidensaul, who wrote a book called "Living on the Wind" about bird migration.
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A Bar-tailed Godwit at San Gregorio State Beach |
SW: "Well, one that really does tie in neatly with wind is a bird called a Bar-tailed Godwit, which is a shore bird. It's a large sandpiper about the size of a pigeon that breeds in western Alaska and it has the longest non-stop over water migration of any bird that science is aware of. It flies from near the Aleutian Islands in Alaska straight across the widest part of the Pacific Ocean, about 6,800 miles, to New Zealand and Austrailia. And it does this in a single, non stop, 4 or 5 day flight. This is a bird that cannot land on water without drowning."
DT: "So how do they pull it off?"
SW: "By picking it's moment of departure, they wait for a big gale to come out of the Aleutian Islands with 70, 80, 90 mph winds. And they wait until the storm has passed and the winds have shifted so they're coming out of the north and they take off into that wind and they let that wind slingshot them on the first leg of their journey. Theoretically, based on computer models, the birds probably wouldn't be able to lay on enough fat to make this almost 7,000 mile trip if they didn't get that boost from the wind in the beginning. Now scientists aren't sure if the birds fly as fast as they can and then add the speed of the wind to their overall ground speed or if they kind of scale back their effort and coast and let the wind carry them, they're still working on that. But it's very clear that the wind is crucially important to this godwood migration."
More about bird migration tomorrow on The Weather Notebook. Our show is a production of the Mount Washington Observatory. Underwriting is provided by the National Science Foundation and by Subaru.
Scott Weidensaul is the author of Mountains of the Heart: A Natural History of the Appalachians and other books. A columnist for the Philadelphia Inquirer, he is also a federally licensed bird bander in the Pennsylvania Appalachians, where he lives. Read an excerpt. |
