It was a sharp-eyed consummate bird watcher who first noticed the Mankato area had become host to one of the most elite species of the North American raptors.

Merrill Frydendall, a retired Minnesota State University ornithology professor, was driving across the North Star Bridge four years ago when he first noticed a crow-sized bird flying above the Minnesota River.

Returning with field glasses, his suspicions were confirmed: The bird was a peregrine falcon, arguably the sky-rocket member of the raptor family, able to make spectacular dives at up to 200 mph to pluck its prey — other birds — out of the sky.

“I’d been watching for the last three years, and it was there every now and then,” Frydendall said. “Then in 2005, there were two.”

The pair frequently could be spotted perched on the idle mixing tower on the old North Star Concrete site. Last year he then spotted a third one, hinting that the pair had nested successfully.

Frydendall then contacted Jacquelyn Fallon of the Midwest Peregrine Project, an organization formed in 1980 at the University of Minnesota to re-establish the species in the Midwest.

After some careful observation and scrambling across the rip-rap along the Minnesota River this spring, Frydendall and Fallon were able to confirm the pair was nesting in the complex of girders beneath North Star Bridge.

The female wears a band. Known as “Betsy,” she was hatched in 2004 on the Prairie Island smokestacks. It is unknown where the smaller, unbanded male originated.

Even in the best of times, the species has never been very numerous.

It is estimated even before the advent of the pesticide DDT, only 30 to 40 pairs of peregrines ever inhabited the Midwest, said Bud Tordoff, a retired University of Minnesota professor who in 1980 founded the Peregrine Project. “In the Midwest, the traditional nesting sites were cliffs and there aren’t too many of those around here,” he said.

With the widespread use of DDT, peregrine numbers dropped precipitously as the chemical hindered egg-shell formation and successful incubation.

Now, after the discontinued use of the pesticide in the ’50s that improved reproduction success and efforts of the Peregrine Project, it is estimated there are more than 200 known nesting sites in the Midwest, including 40 sites in Minnesota.

Urban development actually has been a boon to the birds. The majority of the peregrine nesting sites — about 72 percent — are now found on man-made objects such as smokestacks, high-rise buildings in urban areas, and bridges with only 28 percent on natural cliff sites.

Typical of the species, the Mankato pair selected a nesting site nearly inaccessible and far from human disturbance on the North Mankato end of the bridge.

On Tuesday, with the assistance of a Minnesota Department of Transportation bridge inspection boom and as the adult falcons circled nervously, Fallon attempted to reach the nest site to confirm the number of baby peregrines as well as band them.

She was able to confirm three chicks had hatched. An unhatched egg evidently had rolled from the makeshift “nest” consisting of pigeon droppings and whatever else the adults could scrape from the immediate area.

However, the chicks evidently had hatched much later than suspected. Instead of being 25 days old as originally believed, the chicks were only about a week or so old, Fallon said, far too young and small to successfully band.

What’s more, even with the boom truck, Fallon said reaching the nesting site tucked far beneath the bridge would have been very difficult.

Fallon plans on returning later this month to complete the banding.

In the meantime, Larry Cooper, a MnDOT bridge supervisor who manned the inspection boom, wouldn’t mind at all if he could get peregrines to nest beneath every MnDOT bridge.

“They sure are keeping the pigeons away,” he said. “With them around, the bridges are a lot cleaner.”

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