DULUTH, Minn. -- The snowies have come again.
Snowy owls, denizens of the high Arctic with more than 4-foot wingspans, are showing up in large numbers across Minnesota and other Great Lakes states this winter. Many also have been seen along the New England coast.
Such an unpredictable invasion is called an "irruption" by birdwatchers.
As of last week, an estimated 173 snowy owls had been observed in 57 of Wisconsin's 72 counties, said Ryan Brady, a conservation biologist with the Wisconsin Department of Natural Resources in Ashland, Minn.
That compares with 13 by the same time in 2016-17, 102 in 2015-16, 161 in 2014-15 and 91 in 2013-14, Brady said.
Nine rescued snowy owls have been admitted to Wildwoods, a wildlife rehabilitation facility in Duluth, in late November and early December. "That's far more snowy owls than we've ever had," said Farzad Farr, Wildwoods director.
Only two survived, he said, and both are now recovering at the Raptor Center in St. Paul. One of those, rescued from the base of a chimney at Alakef Coffee Roasters in Duluth, is expected to be released soon, Farr said.
Snowy owl irruptions typically occur about every four years, Brady said, but this year's invasion marks three of the past five years with significant irruptions.
Wisconsin is the only state that keeps a semi-official count of snowy owls during an irruption year, but many have been spotted in Minnesota as well according to Ebird News, a service of the Cornell Laboratory of Ornithology.