ANCHORAGE, Alaska (AP) - Biologists are studying thousands of wild geese, ducks and other migrating birds across Alaska for the presence of avian influenza.

Scientists fear the deadly disease found among wild geese in Asia could be brought to Alaska by the migratory fowl.

Migratory birds from both hemispheres meet in Alaska and could pass on the bird flu, said Jonathan Runstadler, a veterinarian and assistant professor of molecular biology at the University of Alaska Fairbanks Institute of Arctic Biology.

"We potentially could have overlap of viral strains from the Americas and Asia," Runstadler said.

Scientists with the University of Alaska's research project are studying where the different strains of flu virus live, how they spread, how they change and how they interact with birds.

The project includes 30 to 40 field biologists who hope to swab intestinal samples from 5,000 birds from 25 species throughout the state.

The samples will be checked for avian influenza virus. Positive hits will be catalogued in a public DNA database maintained by the National Institutes of Health.

Alaska scientists also plan to compile a geographic database showing types of flu, species of birds and where and when any disease was found.

No evidence exists that Alaskans have ever caught flu directly from wild birds in the state, scientists said. And Alaska's migrating birds have shown no sign of the deadly strain.

Migratory birds had not been thought susceptible to bird flu until an outbreak was first detected about two months ago in bar-headed geese at a saltwater lake in Qinghai, China, a breeding site for birds that spend the winter in Southeast Asia, Tibet and India. The virus also infected brown-headed gulls and great black-headed gulls.

Russian health officials confirmed last week that the disease appeared in poultry in western Siberia near Novosibirsk, possibly carried from Southeast Asia by other migrating birds.