ANCHORAGE - Young golden eagles migrating for the first time don't return to their birthplace in Denali National Park and Preserve in central Alaska, but summer instead in oil-rich areas in the Arctic.
The surprise finding was part of a $250,000, four-year study funded by the National Park Service and the U.S. Geological Survey to track for the first time the migration routes of Alaska's golden eagles.
The results of the study again raise concerns about managing oil development on Alaska's North Slope and in the National Petroleum Reserve-Alaska, and about the increased pressure to open the Arctic National Wildlife Refuge to drilling.
After wintering in the south, the young eagles headed north, bypassing the 6 million-acre national park and flying another 450 to 600 miles to summer on the Arctic coastal plain. A few ended up near the Alaska Range in the Interior or on the Kenai Peninsula south of Anchorage, but most flew north.
"They were all across the North Slope," said Carol McIntrye, a 44-year-old wildlife biologist at Denali who has been studying eagles since 1987. The park is home to at least 100 breeding pairs of golden eagles.
McIntyre worries golden eagles, which are much less tolerant of human beings than bald eagles, won't be able to adapt to increased development in the wilderness, whether it's on Alaska's North Slope or wintering grounds down south.
"We are kind of choking them out of where they live," she said.
Golden eagles weigh 8-12 pounds and have gold and buff-colored feathers on the crown and nape of the neck. They are found in the northern part of the Northern Hemisphere and have been protected in the United States since 1963.
McIntyre said in 1997 and 1999 tiny Teflon backpacks containing small satellite transmitters costing $2,500 each were attached to the backs of 45 golden eagles just prior to their first migration.
The eagles didn't depart Denali until late September and early October, a time when the parents continue to feed and protect them and the young practice their flying and hunting skills.
McIntyre and Michael Collopy, a former USGS scientist who is department chairman of Environmental and Resource Sciences at the University of Nevada in Reno, tracked the birds as they flew south from central Alaska, wintering anywhere from southern Canada to northern Mexico.
Twelve of the 45 eagles survived their first year, often migrating more than 5,000 miles. Most of those that died starved, but some also were hit by cars, electrocuted by power lines, accidentally poisoned and shot, McIntyre said. Most of them died in Canada.
McIntyre said the young eagles probably bypass Denali because the park's adult eagles would drive them off. Their Arctic destination holds a wealth of immature waterfowl, Arctic ground squirrels and caribou calves that make easy prey for the inexperienced hunters.