(Radio Iowa) – New bird flu cases have been reported this fall in Minnesota, South Dakota and Nebraska. The virus hasn’t resurfaced in Iowa since May, but experts are cautioning it could come back as wild birds migrate.  “We can expect that as birds, you know, pass through Iowa and head south, that they may still be harboring the virus.” That’s State wildlife veterinarian Rachel Ruden. She says while bird flu hadn’t been making wild bird sick, a more severe form of the virus has been circulating and that strain has hung around. Iowa State University Extension wildlife specialist Adam Janke says another reason for heightened risk is that birds migrate a lot slower this time of year.

“They’re just trying to survive through the fall and winter,” he says, “and then come spring, they start to focus narrowly on reproduction and that means they need to get north really fast.”Janke says November is the peak time for water fowl, like ducks and geese, to migrate through Iowa. State and federal officials have been surveying healthy birds being harvested by hunters. In September, the bird flu virus was detected in three small ducks that were shot in western Iowa.

The hunting season for blue-wing, green-wing and cinnamon-wing teal ducks was in the first half of September.

(Reporting by Iowa Public Radio’s Katie Peikes)