In the fall, Duluth is famous among birdwatchers for the scores of hawks that fly past. But it's also a birding haven in the spring, when both raptors and songbirds migrate north.
From Thompson Hill is a sweeping view of the St. Louis River as it flows into Lake Superior. It's where several Duluthians come every spring to count hawks.
"Birds are my life. I'm a bird nerd at heart," said Erik Bruhnke, who runs a birdwatching tour guide and photography company in Duluth.
Bruhnke scans the horizon with binoculars and a spotting scope for birds that are barely a speck to the naked eye.
"There's a red-tailed hawk riding thermals, going higher and higher in the sky right now," he said.
Bruhnke said there is no data going back far enough to know whether these red-tails are arriving early. But several species of songbirds, like winter wrens and fox sparrows, have arrived more than a week early. That might not seem like much, but Bruhnke said it is significant.
"It's unusual when birds arrive almost to the exact day, year after year after year, for dozens of years," Bruhnke said. "And all of a sudden there's this unusual warm weather spring, and birds start showing up early. It's concerning, and it really raises some curiosity in terms of what's really going through the birds' minds and what causes them to fly through the area."
Scientists have long thought that bird migration was triggered largely by longer days. To many birdwatchers around Duluth, this early spring suggests that some birds respond to the weather in ways not previously understood.
Just as Minnesotans were inspired to break out the summer wardrobe early, the early warmth may have triggered some birds to take off on their migratory journeys early as well.