Friday, October 21, 2016

Falcons return to the Mississippi with help from surprising places

The late summer sun was fading over a languid Mississippi river, turning the cloudless sky into an ever-so subtle collage of pastels, like the way movie theatres used to illuminate the screen before showtime. Swirling through the warm air, hundreds of chimney swifts dipped and fluttered after mayflies. Semis and SUVs pummeled across the river too, leaping the aquatic hurdle between Iowa and Illinois supported by a handsome suspension bridge, called the Great River Bridge at Burlington, Iowa.

I’ve been to this waterfront a handful of times, usually to scope the Purple Martin houses for occupants. But I had never heard the sound that echoed down from the top of the H-shaped bridge supports that evening. Faint, but unmistakable: the rhythmic screeching of a Peregrine Falcon!

Even with binoculars, the falcon circling the bridge was just a speck in the sky, distinguished from the much smaller swifts by its powerful flight. I watched it twirl upward and land on the top railing, just a tiny smudge against the darkening sky. This seemed an unusual location to me, but I had no idea how monumental it was to see a Peregrine along the Mississippi, until I looked into the recent history of the falcons in the Midwest.

Peregrines are well known as a conservation success story in the United States. They have the widest global range of any bird species, inhabiting every continent except Antarctica. Some sub populations migrate tens of thousands of miles each year, including the Canadian arctic subspecies which migrates to Argentina for the winter. The Latin ‘peregrinus’ means traveler or wanderer. This is a hardy bird.

But in the mid-twentieth century, Peregrines and other birds of prey were dwindling at an alarming rate. Rachel Carson’s famous Silent Spring alerted the public to the threat: the pesticide DDT was moving up the food chain, concentrating in the bodies of raptors and other top predators. The chemical reduced the integrity of raptor eggshells, causing doting parents to accidentally crush them in the nest while attempting to incubate. By the time DDT was made illegal, Peregrines in particular were on the brink of extinction. There was never a country-wide survey of the population before the introduction of DDT, but limited historical data suggests an estimate at 3,875 nesting pairs. By the 1960s, Peregrines were extinct in their eastern range, and by 1975 only 324 known nesting pairs remained in the western states. The species was declared federally endangered in 1973, just a year after DDT was banned.

Thanks to the clever efforts of falconers and wildlife biologists (more about their hilarious yet effective tactics here:, Peregrines have made a comeback, particularly in large metropolitan areas on the East Coast. Since their prefered nesting sites are high cliffs, and their favorite food sources are large flying creatures, they have filled a niche in cities by nesting on skyscrapers and bridges, and providing a convenient service to urbanites by picking off feral pigeons.

If you are from, or have ever been to the Midwest, you might wonder if Peregrines ever lived there. After all, the lack of elevation change might preclude them from nesting. However, historical records do indicate nests along the ridges and bluffs of the Mississippi prior to their population crash. But that’s a long way away from the East coast, and despite the fact that Peregrines are able to migrate to the southern tip of Argentina and back in a year, the birds needed a little help getting a population started again in the Midwest. And they got it from an unlikely source: heavy industry.

Enter Bob Anderson, passionate falconer and conservationist living in Minnesota in the 80s. Inspired by other captive breeders’ success in the east, Bob took it upon himself to help reintroduce falcons to Minnesota. But there’s a problem when it comes to rewildling these powerful hunters. Falcons imprint on their nest site, meaning if a licensed falconer raises chicks in a backyard breeding facility they may continue to return each spring as adults. This may be helpful for training purposes, but not for rewilding an endangered population.

So what’s a rewilder to do? Look for a place that is high up, safe from people and predators such as raccoons and Great-horned Owls, that can act as a surrogate imprinting site. It’s called hacking, a method borrowed by conservationists from the centuries-long history of falconry. The banded, captive-bred chicks are brought to a high cliff or other suitable nesting place in a hack-box, a secure cage with viewing windows for the birds to see and acclimate to their surroundings, while being fed by human parents. In the final days before fledging, a cache of food is left for them and the door is opened, allowing the young birds to practice flying and hunting with little influence and disruption of human presence. Monitored from afar, they are fed surreptitiously until they no longer need it, and they leave on their own time. The method was working on the east coast in various natural and man-made structures.

And that’s exactly what Bob did. His first success was in 1986 from the top of City Center, now called Multi-Foods Tower in Minneapolis, where he released his young fledgling named MF-1 (after the Minnesota Falconer’s Association for which she was produced). The next spring, MF-1 returned to a nest box Bob constructed for her on the top of the skyscraper and raised two chicks of her own - the first wild Peregrines in the Midwest since the 1960s. Not destined to be a one-hit-wonder, MF-1 continued her reign of the City Center tower for 7 more years before being mortally injured in the most honorable way a falcon can - duking it out with a rival female. In the meantime, she produced a daughter who turned out to be another very special falcon in the Midwest.

in 1988, Bob founded Raptor Resource Project, Inc, an organization with a mission to preserve birds of prey through nest site restoration, creation, monitoring and maintenance. Meanwhile, a falconer by the name of Paul Simonet was working at Xcel Energy’s Allen S. King power plant, a natural-gas combined-cycle generator that burns 300 tons of coal an hour. . He saw a male Peregrine hanging around the stacks and excitedly called his friend Bob up with the news. A hopeful but unconvinced Bob came over and, seeing the falcon along with prime nesting potential, began building a relationship with the facility to install a nest box up on the catwalk. Bob and other falcon conservationists monitored the box closely, and discovered in 1990 a young falcon hanging around as if to stay. It turned out to be a banded daughter of MF-1, named Mae, back from her first winter on her own. To the delight of Bob and other enthusiasts, Mae laid a clutch in the nest box on top of the energy plant, hatching a new era of cooperation between conservationists and industry in the midwest.

Bob and RRP partnered with several industrial enterprises across Minnesota and eventually expanding into Iowa. The first industrial nest boxes were all adopted voluntarily by new members (aka dispersing young) of the burgeoning population. After this initial success, as well as receiving results from heavy metals testing in industrial-nesting falcons that revealed no significant increase as compared to urban or control birds, RRP began intentionally releasing young raptors from industrial sites in hope that they would return to nest themselves.

This partnership between conservation and industry may seem ironic. Coal and oil are some of the biggest culprits of greenhouse gases contributing to global warming. But Bob saw an opportunity and ran with it. According to Amy Reis of RRP, Bob worked closely with the plant managers and staff. “He actively maintained relationships with all of our industrial partners: cleaning up messy areas, responding to calls for information and assistance, transporting injured birds when necessary, maintaining and moving nest boxes, and working with the press to raise interest in and awareness of the falcons and the companies that were so crucial to their recovery.” Nesting on smokestacks does have its hazards, such as flying into wires or other tall structures. But apparently it is no more dangerous than the alternative, as smoke stack nests continue to produce more fledglings than either natural or urban sites. And the mortality rate doesn’t approach the number of collisions with automobiles and planes.

Most intriguing of all is the effect the raptors’ presence has on the industrial communities. While RRP has not conducted any formal survey of staff, they note significant enthusiasm for the birds, including an increase in cooperation with RRP in reporting avian mortalities and injuries. Bob also cultivated public support through then-innovative means: nest cams! His first web cam project, “possibly the first internet-based bird cam” according to RRP, featured Mae atop the Allen S. King Plant in 1998, and exposed thousands of viewers to the intimate home life of these previously mysterious creatures.  In her eighth year as Xcel queen, she became a celebrity followed closely by viewers for the rest of her 14-year breeding reign, when she faced the same honorable demise of her mother, at the talons of a rival.

By 1998, the populations of eastern Peregrines were rebounding successfully, reaching pre-DDT estimates of one to two thousand pairs. But something was bugging Bob. Despite a growing midwest population, the raptors had not yet begun nesting on their historical eyries on the cliffs above the Mississippi. He decided to conduct a hack program from Effigy Mounds National Monument in northeastern Iowa. The program was a success, and a few years later, not only was the Peregrine removed from the Federal Endangered Species list, but Bob watched proudly as young from his industrial nest boxes began breeding with the Effigy Mounds progeny, completing the link between history and the future, and strengthening the genes and nesting-site elasticity of midwestern Peregrines.

Unfortunately, Bob passed away in July of last year, 2015. He continued his work with passion, even rappelling down stacks and cliffs to band chicks until the last years of his life. Yet, his legacy continues to trickle down the Mississippi. His captive-bred chicks have contributed over 1500 progeny in the US and Canada over the past three decades, adding to the efforts of Iowa and Minnesota Departments of Natural Resources own captive-breeding projects. As of summer 2016, MF-1 could boast being mother, grandmother, etc to 512 wild descendents, according to the dedicated monitoring of RRP. The Great River Bridge in Iowa is tricky place to resight bands, but it has been occupied for the last ten years. Perhaps some of Bob’s extended feathered family have nested up there too. In the last few years, World Bird Sanctuary, Inc in St. Louis has successfully released Peregrines along their length of the MIssissippi, extending their reach further into the historic range.

Thanks to the innovative, open-minded dedication of Bob and other falcon conservationists, the piercing cry of the Peregrine can be heard echoing over the Mississippi once more.

Special thanks to Amy Reis of Raptor Research Project and Pat Schlarbaum of Iowa Dept of Natural Resources for taking time out of their busy schedules to answer my questions via email.


  1. Good blog, Kaitlin!
    One note of clarification is that the reintroduction of Peregrines in Minnesota started in 1982, led by The Raptor Center (University of Minnesota) and other partners. (
    Bob graciously hosted our traveling University of Iowa Wildlife Camp at his hacksite at Effigy Mounds in the ' experience which none of us involved will forget. He had (a) vision!

    1. Thanks so much for reading and for the clarification, DJC! Do you know if Raptor Center also encouraged industial partners to "adopt" peregrine neighbors? Or if they have a different perspective on it?

  2. When I served as a hacksite attendant on the Mayo Clinic in 1988, they were also doing natural site releases, such as on Isle Royale. But other than urban and wilderness release sites, I don't remember industrial releases or partnerships.