Nasty spring weather had birds migrating backward in Duluth

What happens to early spring bird migrants when the weather turns surprisingly nasty? Northbound birds turn around and head the other way.

Jan Green, a longtime birder in Duluth, sent a note on April 19 about thousands of birds flying west along the city's lakeshore. Jan and her husband, John, watched this reverse migration from their apartment.

(Westbound is southbound in this story, given the geography of Duluth.)

"Weather event of snow, sleet, fog and freezing rain led to a massive reverse migration low and close the Lake Superior shore. Estimated at least 10,000 birds per hour morning through afternoon," Jan wrote.

Species were mostly blackbirds, finches, sparrows, robins, flickers and warblers, she said. Total number estimated at 100,000 birds.

"I've seen lots of reverse migration in spring since 1960 but never before at this magnitude," she said.

Duluth experienced record snowfall this winter, breaking a record set in the 1995-96 winter.

But at some point, the birds turn around and try again: May 15-21 will see peak songbird migration in Minnesota, according to the Cornell Lab of Ornithology. The lab used information from its BirdCast program, involving radar data, to predict dates.