NEAR WEST SIDE — Armed with bike helmet, rope ladder and cat carrier, Mary Hennen makes her way down the side of a building to strong-arm a few baby falcons.
The falcons — three peregrine chicks — are huddled on a ledge on the top floor of University of Illinois at Chicago's University Hall building, a 28-story tower where the birds have nested for the previous two seasons.
This is Hennen's 26th year as director of the Chicago Peregrine Foundation, a volunteer group through the Field Museum that tracks peregrine falcons across Illinois. Now that UIC's chicks are big enough (between 21 and 24 days old), Hennen's goal is to get them inside, tag them, take blood samples and then slip them back out on their cozy 28th-floor nook.
Chloe Riley discusses how Hennen captures the birds on DNAinfo Radio:
The birds, Hennen said, were innately drawn to UIC's tower: It's the tallest thing on campus and resembles a cliff, perfectly mimicking the birds' natural nesting habitat.
In order to reach the babies — which still don't have names — Hennen has to suit up and rappel through a window and onto a ledge. The helmet protects her from the chicks' parents (a female named Nitz and a male named Mouse) who will divebomb her from the air as she tries to gather the chicks into a cat carrier.
In the 1960s, peregrine falcons were almost wiped out as a species in the Midwest, due to high levels of the chemical DDT in the area. Efforts by groups like Chicago Peregrine have helped the species recover, and now more than 27 pairs of the birds make their home in Illinois.
Loud shrieks erupt from the adult falcons as Mary descends a rope ladder toward the chicks. The babies — three large gray marshmallows with talons — peep back as they're placed in the carrier.
Back inside the building, each baby is taken out one at a time and held down as Hennen takes blood samples and attaches bands around the birds' legs. Monitoring the birds' whereabouts became mandatory after 1999 when peregrines were taken off the federal Endangered Species list.
As Hennen pulls each squawking chick from the cat carrier, she declares two males and one female. She said she used to hope for male chicks, as the metal bands for males used to be easier to secure.
"Now this new set I have is much easier, so now I'm rooting for girls," Hennen said, smiling.
Reduced to only one pair of falcons in 1988, Illinois peregrines totaled more than 20 pairs by 2007, with the highest concentration being in Chicago, according to the Field Museum's website.
While the birds' mortality rate is high — nearly 60 percent won't make it through the first year, Hennen said — peregrine falcons that do survive can live close to 20 years.
And with the steady diet of small birds and pigeons that UIC's falcon chicks are getting, Hennen said they seem like they'll do just fine.
"They look nice; they were in good health," she said of the chicks. "Parents were doing exactly what they were supposed to do, defending the nest and yelling at us."
Those interested in following the UIC falcon babies can check out the live webcam at the school's website here.
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