Story last updated at 7/22/2009 - 12:13 pm
Bob Gill had to look twice at his computer the other day. The two birds he was tracking in Alaska via Google Earth had veered off the lower right corner of the computer screen.
Those birds, whimbrels that Gill and others had captured and fitted with a satellite transmitter in the heart of Interior Alaska about a month before, had migrated out of the state by mid-July. The birds leapt into the air from western Alaska and caught tailwinds down south. One bird was winging its way over the ocean west of San Francisco, and the other was in Mexico.
"Judging by all the flight speeds, the bird flew nonstop from just south of St. Marys, Alaska, to the Baja Peninsula just south of Ensenada," said Gill, a biologist with the U.S. Geological Survey Alaska Science Center in Anchorage.
The ptarmigan-size shorebirds with roundish bodies and long, curved beaks seem to have a knack for taking long flights timed with weather systems that push them along, Gill said. The bird that went to Baja was moving as fast as 37 mph.
"These guys have got this stuff hard-wired," Gill said. "They get ahead of these storm systems and get these great tailwinds."
The whimbrels Gill and others track are two of 15 birds captured in Kanuti National Wildlife Refuge and outfitted with satellite transmitters that a wildlife veterinarian inserted into their abdomens. The refuge, which includes most of the Kanuti River drainage between the Dalton Highway and the Koyukuk River, is about as far from the ocean as a shorebird can get in Alaska. Most of the Delaware-size refuge acres are boreal forest, rich in black spruce and boggy lowlands.
Chris Harwood, a Kanuti biologist, spent the spring in a cabin on the refuge last year and noticed the "qui, qui, qui, qui" whistle of the whimbrel.
After spotting the birds, he got in touch with Gill, whom he knew studied shorebirds. Gill is interested in birds such as the bar-tailed godwit; he discovered a few years ago that some godwits make nonstop flights from Alaska to New Zealand in fall.
Gill was intrigued with Harwood's whimbrel discovery, and he and a few other team members flew to Kanuti in early June 2009. Harwood had located 17 whimbrel nests on a patch of tundra not far from the refuge cabin, and a team of biologists captured 15 birds and implanted the satellite transmitters in them in three days in early June.
By July it was time to check the laptop and see where the birds had headed.
The whimbrels had already bred and reared young in Kanuti, with the father birds lingering to help the fledglings after the mothers had moved on.
Where the whimbrels went after Kanuti was anyone's guess. Gill and his team had fitted a whimbrel on the Seward Peninsula with a transmitter a few years ago, and that one had traveled to the Salton Sea in California, then on to Columbia. An East Coast whimbrel made headlines last year by migrating from Virginia to the North Slope.
The Kanuti whimbrel that is now in Mexico seems to have bred in Interior Alaska, and, with that mission completed, flew to the tundra southeast of St. Marys on the Yukon River. There, it spent 15 days, probably fattening up on berries and insects, and then set off for a nonstop flight to Baja.
"I would have thought they would have required more time on the feeding ground," Gill said. "Either they're putting down fat/fuel faster than we think, or they're more efficient using that fuel to go migrating distances."
And where will the whimbrels go? Gill said the birds spend their winters (and late summers, apparently) "anywhere from California to Tierra del Fuego."
This column is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Ned Rozell is a science writer at the institute.