Squawker on a beam. Photo by Neal Ney

Students from Northeastern Illinois University were boating on Crooked Tree Lagoon in Belize, Central America, one morning when they found themselves in the midst of an enormous raft of coots – black chicken-like water birds.

One curious student asked if peregrine falcons were found in Belize. Almost immediately, literally out of the blue, came the answer: a rocket, diving full-speed ahead, sunk its talons into one unlucky coot. The falcon flew up with its prey, which proved to be too heavy. After dropping it three times, he left it “in the refrigerator until later,” as the guide said. Although coots are not related to ducks, this behavior is responsible for the peregrine falcon’s moniker “duck hawk.” In full pursuit, peregrine falcons are quite possibly the fastest animal on the planet on a short dive, but not when carrying a heavy load.

Peregrine falcons breed on every continent except Antarctica and are absent from the Asian steppes, the Amazon basin and the Sahara Desert. The species name peregrinus means “wanderer.” Early Evanstonians might have noticed peregrines migrating along the lake on their way to the tundra to breed. Primarily birds of open fields (good for hunting) and rocky cliffs (good for nesting), and near water, the closest nesting peregrines were on Illinois’
Mississippi River bluffs.

Peregrine falcons are exceptionally handsome birds. Adults have bluish black backs and long, pointed wings with black wingtips. They have blackish heads and a distinctive facial stripe or mustache extending downward on their cheeks against a whitish or buffy neck. Their underwings are lightly striped. Their under-parts are greyish or buffy and spotted or striped. Males are one-third smaller in size than females and are called tiercels. Fledglings are called eyases and are downy white.
In 2008, Field Museum scientists were astounded to discover an evolutionary surprise: the peregrine falcon is more closely related to the parrot than to hawks. Other surprising research showed that both species molt their feathers annually in the same order and unlike any other species – each species molts feathers in a definite sequence.

Human/falcon relationships go back thousands of years. Early humans probably hunted the birds for food. Over the years, humans began to train falcons and other birds of prey to be their hunting partners. As the sport of falconry grew, it was often restricted to the gentry.

Most Illinois peregrine falcon prey are mid-sized birds, such as blue jays, cuckoos, pigeons, doves, flickers, and woodcocks. Peregrines also favor bats. These carnivores have several styles of pursuing prey, the most famous being the “stoop,” during which they dive through the air with incredible speed and precision.

Folding their long, tailored wings back and using their powerful chest muscles, these birds can achieve dive speeds that exceed 200 miles per hour. They often catch prey in mid-air.

Another hunting method involves “ringing up,” if the prey are above the falcon. The falcon forces the prey to fly upward, tightening the noose in ever smaller circles from below until predator and prey are nearly one or until the prey begins to drop from exhaustion. During breeding season, falcons often hunt from a perch, surveying their surroundings for potential victims.

Peregrines usually mate for life. Even though they may not migrate and may stay close together in winter, they still perform courtship rituals before nesting begins. Courtship may be mellow – slow flight, hunting together, ledge displays such as bowing and transferring food near potential nest sites. Or it may be dazzling, with both birds spiraling higher and higher doing figure eights and loop-de-loops. A mated pair will likely return to the same nest site, which is usually just a “scrape” in gravel made by both sexes. Nests are called eyries.

In late March or early April, an egg may be laid every two to three days; the average clutch is four. The female is the primary incubator, but the male will take a turn, his size challenging him to get all four eggs under his smaller body. The incubation period can span 28 to 33 days. The nesting period is usually 4½ to 6 weeks, and the fledgling phase lasts another 6 weeks.

Human hunters took their toll on the peregrine falcon as well as other birds of prey. Peregrine falcon eggs were prized by egg collectors for their beautiful rich brown pigments, which are applied in the oviduct during laying. Both hunting and egg-collecting were banned in the early 20th century.

No depredations compared to the losses sustained after World War II. In the late 1940s through the early 1970s, the use of chlorinated hydrocarbons, primarily DDT, affected the egg shells of birds at the top of the food chain; shells thinned and shattered when adults tried to incubate them. Peregrines became extinct east of the Rockies. The Migratory Bird Act of 1972 and the Endangered Species Act of 1973 were passed to combat the harm done, and the Environmental Protection Act banned the use of DDT in the U.S. in 1972.

Laws alone would not have been enough to save the peregrines. Fortunately, the birds captured the imagination and passion of many people, including Tom Cade of Cornell University. He founded the Peregrine Fund in 1970 with the hope of re-introducing the species into large regions where they formerly roamed.

With the help of falconers, the Peregrine Fund first released birds into the eastern states, then quickly followed suit in the Midwest. Illinois releases began in 1986. Today’s Illinois-breeding falcons are indeed a regional population. They come from Illinois, Wisconsin, Indiana, Minnesota, Missouri, Ohio, Nebraska, Iowa and Canada.
In a real conservation triumph, peregrines were removed from the U.S. Federal Endangered Species list in 1999. In Illinois, they were upgraded and reclassified to “threatened” in 2005. Preliminary approval has been given to remove them from the “threatened” list in Illinois as of 2015 and final approval should come later in the year.

Tall buildings in cities now provide popular ledges for peregrines to breed.

The first falcon pair to settle in Evanston bred successfully in 1999 on the  First United Methodist Church at 616 Church St. (a popular roosting place for the present falcons), and failed in 2001 from a new nest-site in the gutter of what is now Panera at the corner of Church Street and Sherman Avenue.

So that their wanderings can be tracked, accessible birds are given leg bands with numbers. Records are kept by the U.S. Geological Survey Bird Banding Laboratory at Patuxent Wildlife Research Center in Maryland, in cooperation with its Canadian counterpart.

Names are much easier to use for conversational purposes. Tracy, the United Methodist male, was bred on Broadway in Chicago, and the female, Zoom, came from Minnesota. Eventually, Zoom moved to Uptown and bred there for years, while Tracy moved back to his natal nest on Broadway. Not all peregrines mate for life.
Since 2004, for 12 years, peregrine falcons have been breeding among the downtown Evanston Public Library pillars. The first male was named Joel, who had fledged on Wacker Drive in Chicago. His first mate was Sarah. The current pair, Nona and Squawker have been together for 10 years. Three of their offspring have been known
to breed.

This year, Nona laid the first egg on March 30 and the fourth egg on April 7. Hatch day is anticipated around May 7. Over the years, the couple has raised 27 chicks, all of which have been banded by Mary Hennen, director of the Chicago Peregrine Program at the Field Museum.

Ms. Hennen says, “Personally, I like to think of myself as a liaison for the peregrines to the public.  It’s not just being an observer. You’re an active participant in scientific data collection, assisting the peregrines in being successful breeders, and educating the public about not just the peregrines but conservation and other ecological issues.”

In addition, the Evanston Peregrine Falcon Watch, a group led by Deborah Cohen, is composed of dedicated Evanston Peregrine watchers. On their Yahoo group site, members post information about the falcons, record data and events, and share the joys of watching the birds as they have matured over the years and developed distinct personalities. Anyone may join.

People wishing to observe the falcons “up close and personal” can oogle EPLfalconcam, which has a link to the Evanston Peregrine Falcon Watch site. As the young grow, they will put on quite a show, taking their early flights around downtown Evanston near the library.

Libby Hill is the author of "The Chicago River: a Natural and Unnatural History. She has been writing about birds and trees and Evanston's natural history for the Roundtable since 2004.