Raptor Revival


The peregrine falcons of Mayo Clinic: 30 years of following fledglings
By Amy Brase

In the late months of winter before a splash of color returns to the landscape, downtown Rochester keeps an eye to the sky for a few beloved friends to return.

Best known for their long migratory flights and title of fastest members of the animal kingdom, the peregrine falcons receive a warm Minnesota welcome as they take up residence among the tallest buildings of Mayo Clinic. 

The falcons’ recovery and revival has been nothing short of remarkable since not a single nesting pair could be found in the Midwest in the early 1960s.

According to the U.S. Fish and Wildlife Service, this was due to increased use of a new insecticide after World War II called DDT. Raptors fed on contaminated prey and became subsequently poisoned, which caused their egg shells to be fragile, thin and ultimately break during incubation. DDT was later banned in 1973.

Saving the Falcons 
Recovery efforts began for many threatened species, including the peregrine falcon. In 1987, the Midwest Peregrine Falcon Society and the Raptor Center at the University of Minnesota invited Mayo Clinic to partner with them by building a nesting box atop the Plummer Building.

Over the years, the man-made nest moved to the Guggenheim and has now settled into its permanent home atop the Mayo Building, 250 feet above the street. The idea was to band and release captive chicks to track falcon migration and life longevity.

The collaborative effort resulted in the raptors being removed from the endangered species list in 1999. There are more than 40 pairs of nesting peregrines in Minnesota today, and Mayo falcons have been spotted as far south as Texas and north into Canada.

“It’s been a huge success,” says Thomas Behrens, Mayo Clinic facilities operations unit head and manager of the Mayo Clinic Falcon Program for 25 years.

“I can hear them downtown before I even see them. They have a very distinct screech. Peregrine falcons are easy to spot once you know what you’re looking for. Toward the end of February, beginning of March, they naturally migrate back into the Midwest, and females begin fighting over the territory.”

Not in the Job Description
The peregrine population is thriving, but there are limited places to live. Rather than building nests from twigs, peregrines find a shallow dip in rocks or on the ledge of a cliff near water.

In urban settings, they prefer tall buildings, towers and bridges that mimic cliffs. The male typically returns to the nesting site first and sits and calls for the female to return, too. They mate for life, and the drive to reproduce is incredibly strong.

“They are committed to the nesting site more than to each other, though,” explains Behrens, who has been involved in the program for 25 years. Though none of this could be found in his job description of caring for buildings and grounds, he has been climbing on roofs to hang nesting boxes, banding and monitoring the feathered friends since day one.

“The crazy part is when the fledglings start learning to fly around two to three weeks of age; I’ll get a call from someone on my grounds crew,” Behrens says as he describes the excitement the falcons stir up as they fine-tune their flight skills.

“Sometimes one will land on Second Street and block traffic. They are very territorial, too,” he says. “If I climb up on the roof, I’ll get a visit. They fly by and screech at me.”

Famous with Patients
Mayo Clinic patients enjoy following the falcons as they nest, lay eggs and hatch offspring. Mayo offers an informative display about the falcons in the subway level of the Mayo Building, next to the patient cafeteria. In addition, patients on campus can watch a 24/7 EarthCam of the nesting box on Channel 199 and 706HD on the patient television network.

“During the breeding season, Jackie Fallon brings a live peregrine down to the subway to visit with patients every Monday,” says Behrens. “She’s the vice president of field operation for the Midwest Peregrine Society and is a wealth of knowledge. Patients will schedule their appointments just to be here during this time. They’ll want to know things like ‘How many eggs this year?’”

Fourteen hundred people submitted name ideas for the most recent chicks born in Mayo’s nesting box to the proud peregrine parents, Hattie and Orton. The three were banded at Mayo Clinic on June 1, 2017. In keeping with tradition, each falcon was given a special name of significance:

Generose, female, named after Sister Generose Gervais, the fifth and final Sister administrator of Saint Marys Hospital

Epic, female, named after the Plummer Project – Epic Implementation, the largest practice initiative ever undertaken by Mayo Clinic

Lucky Lindy, male, named after Charles Lindberg, a Minnesota native who collaborated with Mayo’s medical unit in World War II, which developed the G-suit, high-altitude oxygen mask and other innovations. 2017 marked the 90th anniversary of Lindbergh’s trans-Atlantic flight.

The Mayo Brothers had a strong respect and reverence for the healing power of nature. Today, patients can enjoy nature not only through the beauty of manicured grounds but also in the amazing falcons who soar outside their windows.

“There’s more than medicine that heals people,” says Behrens. “The falcons are one thing that helps patients get their mind off their appointments for the day and focus on something different.”

Follow the Falcons: A Timeline
February: One male and one female take up residence in the nest on the roof.
Between March and April:
The female lays 2 to 4 eggs. 
Early to Mid-May: Eggs hatch and chicks grow rapidly and fledge about about 6 weeks of age.
Mayo Clinic traditionally names the baby chicks. 
June 1: Banding Day – Mayo Clinic employees and patients on campus are welcome to attend.  Summer to Fall: The young falcons develop under the watchful eyes of their parents until they can fly and care for themselves independently. Parents depart then, too.

Fun Falcon Facts
Latin name: Falco Peregrinus, which means “wanderer”
One to 2.5 lbs. with long, pointed wings
Males are one-third smaller than females
Adults have a blue-gray back with a light, striped underside and dark-colored head
Young birds are brown and cream colored with heavily marked streaks
Mind-blowingly fast! Their aerodynamic structure allows them to reach speeds over 200 mph when diving.
They hunt and feed on other small animals, typically birds, which helps control the pigeon and crow population
The falcons can migrate more than 15,000 miles per year
Sources: smithsonianmag.com  http://history.mayoclinic.org/tours-events/mayo-clinic-peregrine-falcon-program.php

Amy Brase is a local writer who will be keeping an eye to the sky for Rochester’s famous raptors this spring.