BECKER, Minn. — Four decades ago, watching a peregrine falcon soaring through the sky east of the Mississippi River wasn't possible.
The fast-flying raptors hovered on the brink of extinction after widespread use of the pesticide DDT reduced their ability to produce viable eggs. By the 1960s, the peregrine population had declined to roughly a dozen pairs in the western United States.
That history made the rain-soaked scene at the Sherco power plant earlier this month even more remarkable, the St. Cloud Times reported (http://on.sctimes.com/17JSbUT). A group of schoolchildren watched through a telescope as Brian Schmidt removed four fuzzy, whitish-gray chicks from a nest box 450 feet up the smokestack and brought them down to the ground to be banded.
"Just seeing four peregrines right now is a pretty big success story," said Schmidt, an environmental analyst with Xcel Energy, which owns the Sherco plant.
Peregrine falcons made a dramatic recovery after DDT was banned in 1973. A captive breeding and release program helped increase their numbers, and they were removed from the endangered species list in 1999.
There are now between 2,000 and 3,000 nesting pairs in North America, according to the U.S. Fish and Wildlife Service.
About 25 years ago, Xcel began putting nest boxes on its power plant stacks. The first nest box was installed in 1990 on the Allen S. King Plant in Oak Park Heights. Since then, the program has been copied by other power plants worldwide.
The boxes are installed 300-600 feet above the ground to imitate the high cliffs where peregrine falcons prefer to nest and perch. Webcams offer the public views of the eggs and, after about 33 days of incubation, the chicks hatched. Xcel has falcon cams on two other Minnesota power plants, including the King plant and Black Dog in Burnsville.