(CNN)Idaho wildlife officials have retrieved 2,000 dead snow geese that fell from the sky  this week. The birds, whose carcasses were collected over the weekend, appear to have died of avian cholera, the Idaho Department of Fish and Game said Tuesday. "The migratory birds were on the return leg of their migration from the southwestern United States and Mexico to their breeding grounds on the northern coast of Alaska," said Steve Schmidt, a regional supervisor. They died near Dubois,  Terreton and  Roberts -- all in the eastern part of the state. It's unclear where the geese picked the bacteria from, but authorities are scrambling to ensure that other birds don't feed on the carcasses and spread the disease. "The important thing is to quickly collect as many of the carcasses as possible, to prevent other birds from feeding on the infected birds," Schmidt said. "Biologists observed about 20 eagles in the vicinity of some of the carcasses. Because of a delayed incubation period it is uncertain where these eagles might be located, if and when the avian cholera affects them." Though the official lab results are not out, officials said the cause of death points to avian cholera. Humans are not considered at high risk of getting the disease, according to U.S. health officials.
The birds were on the return leg of their migration from the U.S. and Mexico . Wildlife officials say they appear to have died of avian cholera .