Like the movement of a school of fish, a flock of blackbirds flew in waves above bronzed fields as sunset neared. An open window let in the squawky honks of Canada geese flying in Vs over trees. Cranes and egrets gathered in grasses and near wetlands, feasting before the seasonal liftoff and journeys south.
Signs of migration can be seen across Minnesota's rural landscapes every fall, but new technologies and expanding research are raising the wow-factor.
"Birds go farther and faster and have broader migratory routes than we thought," said Dr. Jeff Wells, science and policy director with the Boreal Songbird Initiative. "This new evidence shifts our understanding of what migratory birds need."
A recent report, which also involved Ducks Unlimited and the Cornell Lab of Ornithology, showed that northern landscapes matter as much, if not more, than winter tropics. Billions of migratory birds use them for nesting grounds before taking epic journeys south.
For most species, especially songbirds, the journey takes place quietly, stealthily as people sleep. An estimated 30 million to 50 million birds fly across the United States and Canadian border each night from late summer through November, with the cloak of darkness protecting them from predators. Birders attuned to modern tracking watch weather radar as the sun goes down.
"You'll see these clouds show up on radar as [birds] lift off at night," Wells said. "It's pretty striking in many areas."
Radar, geotagging, and other technologies are making it easier for biologists and researchers to follow the journeys of an estimated 300 species that breed and nest in the boreal forest. That biome roughly stretches from the interior of Alaska and north of Canada's prairie before dipping into the northern United States and east to Newfoundland. Minnesota ranks among the most important U.S. states for the boreal landscape, which includes the highest amount of surface freshwater in the world along with some of its largest and most notable lakes.
"We sometimes call it 'the forest of blue,' " Dr. Wells said.