"An unprecedented wintertime outbreak of West Nile virus has killed more than two dozen bald eagles in Utah and thousands of water birds around the Great Salt Lake, state wildlife officials said on Tuesday."
"At least 27 bald eagles have died this month in the northern and central parts of Utah from the blood-borne virus, and state biologists reported that five more ailing eagles were responding to treatment at rehabilitation centers.
The eagles, whose symptoms included leg paralysis and tremors, are believed to have contracted the disease by preying on sick or dead water birds called eared grebes that were infected by the West Nile virus, said Leslie McFarlane, Utah wildlife disease coordinator.
Some 20,000 of the water birds have died in and around the Great Salt Lake since November in an outbreak that may be a record in North America, McFarlane said. Initial testing suggested an infectious bacterial disease such as avian cholera caused the deaths, but findings released on Tuesday showed West Nile virus was the culprit, McFarlane said."