In the next few weeks, millions of songbirds, shorebirds and waterfowl will begin arriving in Alaska to breed. These migratory birds -- some of which wintered in Southeast Asia -- could bring with them the deadly strain of bird flu known as avian influenza A, or H5N1.
The U.S. government has set an ambitious goal of testing 100,000 birds for the virus, mainly in Alaska, where wildlife biologists, researchers and public-health officials are hurriedly preparing for the first flocks to land.
The springtime arrival of birds is a traditional sign that winter's icy hold is broken. But winter is stubborn in Alaska, and the first sign of spring -- the snow bunting, a small songbird -- has yet to arrive in Fairbanks.
Alaska is a hot spot for migrating birds. The snow bunting promises to be the first arrival of about 42 species and an estimated six million birds. Most fly from Asia to Alaska in an annual cycle, and public-health officials and scientists aim to catch and test at least a fraction of them this spring.
The hope is to detect the bird-flu virus if and when it first arrives, and predict where it will spread next. And scientists aren't just looking at the birds to find the virus.
Last year, veterinarian and immuno-geneticist Jonathan Runstadler led a team of researchers at a remote migratory bird "bus station" called Creamer's Field Waterfowl Refuge to collect virus samples. He recently returned, drilling holes in the ice to get at the frozen muck below -- muck made mostly of bird droppings from last year's migration.
So far, the H5N1 strain has not been found. But, there are at least 144 types of other nonthreatening bird-flu viruses, and Runstadler is interested in looking at all of them.
"This is perhaps an ideal place to find influenza viruses," Runstadler says.
His concern is that avian-influenza viruses can survive during the winter and re-infect birds on their return. He and his fellow scientists want to get a better picture of how viruses move around and how fast they could spread across North America. Runstadler's work is just one small part of the research happening in Alaska, which is suddenly center stage as scientists try to predict where the virus will appear next.
George Happ, the director of biomedical research at the University of Alaska, says all eyes are on the state -- and it's a little scary.
"We can use this potential pandemic as an opportunity to understand the disease better," he says. "If we know how those viruses evolve, this gives us certainly help in how to develop vaccines."
Scientists in Alaska have been studying virus evolution and bird migratory patterns for years, but now the need for answers is more pressing. With the federal government's help, about 20,000 birds might get screened this season.
But even with help, the task is huge. Kevin Winker an evolutionary biologist, ornithologist and museum curator, looks up at a huge map of Alaska in his office.
"If your mission is early detection of a single strain, it's hunting for a very small needle in a very large haystack."