How Minnesota's peregrine falcons returned to the cliffs after local extinction
Each spring, volunteers in Minnesota rappel down cliff sides, climb under bridges and scale buildings, all hoping to discover more about “nature’s missile” — the peregrine falcon.
"What we are discovering is rewriting the text books about peregrines," said Jackie Fallon, vice president of field operations for the St. Paul-based Midwest Peregrine Society.
Thousands of peregrine falcons in the United States are monitored through decades-long bird banding efforts. Fallon, a Twin Cities resident, visited her first peregrine falcon nesting site in St. Paul in 1988.
"I've been hooked ever since," she said.
In recent days, Fallon and groups of volunteers have traveled around the North Shore, banding chicks found on cliff sides, islands and elsewhere — the season's exhaustive banding efforts should be complete before the end of the month.
Chicks are found south of Winona all the way to up to Grand Portage, over to Brainerd, through St. Cloud and beyond — Minnesota is prime real estate for peregrine falcons.
"Most large cities in our region are near water and that's what brings their food source to them," Fallon explained.
Peregrine falcons, able to reach straight-line flight speeds of 70 mph and stoop speeds in excess of 240 mph, are the fastest animal on the planet.
While there's over 350 nesting pairs in the Upper Midwest today, there were none just over a half-century ago.
Before the reintroduction efforts took hold, Minnesota lost sight of the species in 1963 — that's when the state's last known peregrine falcon, documented at Whitewater State Park near Rochester, vanished. DDT, the insecticide widely used on agricultural crops in the 1950s and 1960s, had completed wiped out the population.
The Midwest Peregrine Society, now a non-profit organization powered by donations, was founded in 1970 by a group of falconers.
With a $3 million investment, approximately 1,300 peregrine falcons were purchased from captive breeders and released in the Midwest region in the 1980s and 1990s.
Back in the wild, the raptors returned to the cliffs they had historically inhabited for thousands for years, Fallon said. Many others found success in urban areas, nesting atop buildings and other tall structures. Over 100 chicks, for example, have been hatched at the Colonnade building in Golden Valley over the past 30 years.
"Peregrines are more adaptable than we ever gave them credit for," Fallon said, adding an 18-year-old peregrine falcon nesting on a bridge in Mankato is the oldest in Minnesota.
While the species' recovery exceeded all expectations, Fallon said the future of peregrine falcons and other raptors depends on the availability of clear air, fresh water and safe food.
While the birds no longer face the threat of DDT in the United States, they do risk coming into contact with the chemical in other parts of the world during migration — that's something Fallon and other volunteers are keeping watch for by testing the birds' feathers.
During this year's banding efforts, volunteers are feeling relief as the state's avian influenza outbreak spared peregrine falcons. Statewide, researchers only know of one nesting site in Bloomington where chicks failed to hatch after their mother succumb to the virus.
That leaves roughly 120-150 young peregrine falcons taking flight in Minnesota this year alone.
