Eagles, ospreys and falcons are some of the most creatively adaptive members of the raptor family. Learn how these birds are surviving and where to find them in our region.
Of the birds of prey found in northern Illinois, there is none more iconic than the bald eagle. This fierce raptor has been our nation’s emblem since 1782, and rightfully so. Like other raptors, it took a major blow in the 1970s, during the time humans used DDT and other pesticides. But with careful protection, these distinguished birds rebounded and were removed from the federal endangered species list in 2007. Today, they serve as symbols not only of patriotism, but resilience.
“In the winter season, in the Rockford area, we have quite a few birds that stay around,” says David C. Olson, a photographer based in Rockford. “Now’s the best time to view these birds because their numbers are at the highest.”
Olson used to travel as far as Alaska to capture images of bald eagles in the wild. Now, he’s delighted to find these birds within driving distance and even in our own communities. Hundreds to near thousands of bald eagles can be found nesting along the Mississippi River, Rock River, and the regional lakes and reservoirs of Illinois and Wisconsin. The winter months, up until early March, are the best time to spot them gathering in large groups before breeding season.
Other birds of prey still grace our region’s skies, too, but not every species has recovered as significantly as the bald eagle. Agile and extraordinary raptors, from ospreys to falcons, are still adapting to the changing landscape and conditions affected by human activity. Some have found new ways to thrive, others still struggle.
“It took such a spectacular creature like the bald eagle for people to take notice of the effect we have on these species,” says Nabeel Rasheed, bird handler at the Northern Illinois Raptor Center in Hoffman Estates. “Once people start realizing that these are worth saving, stewardship can filter down to the rest of the wildlife that we have.”
Top of the Food Chain: Eagles
The bald eagle’s recovery is an encouraging success story. With northern Illinois’ riverways and winter season, our region is a perfect host for them during their winter migration.
“We have people traveling from all over the country now to view our eagles in Illinois, which is pretty cool,” says Olson.
One of the largest birds in North America, bald eagles are easily recognized by their dark-brown bodies, white-feathered heads and bright yellow bills and legs. Their wingspan ranges 6 to 8 feet with a height of 30 to 37 inches. Females, which are larger than males, can reach up to 14 pounds in northern habitats.
Hunting along rivers and other bodies of water, bald eagles like to perch and nest on the edge of neighboring forests for a wide view of their surroundings. Fish, including bass, herring, shad and catfish, make up most of their diet, but they’ve been known to go after a variety of birds, reptiles and mammals. Eagle watchers are sure to be entertained by an eagle on the hunt. When they’re not skillfully attacking their prey with a sharp-hooked beak and talons that can lift up to 4 pounds, eagles have been known to steal prey from other animals and even humans.
“Eagles are very smart and opportunistic all around,” says Candy Ridlbauer, executive director of Northern Illinois Raptor Rehab and Education in Loves Park. “During the winter, when rivers and lakes freeze over, you’ll see them gather around dams where there is turmoil and the fish are somewhat stunned. We’ve heard from some fishermen that eagles will come in and literally steal fish right off their lines.”
This thieving tendency has led to the species’ expanding range. As fierce territorial birds in constant competition for food, juvenile bald eagles are driven from the nest by their parents, during autumn, before the next breeding season begins. These younglings then spend the first four to five years of their lives exploring new territories and flying up to hundreds of miles per day before reaching sexual maturity and nesting with life partners.
“We’ve heard in the past few years that some juvenile eagles are going more inland, so potentially, that could be adding other animals to their diet,” says Ridlbauer. “There have been more sightings, but a lot of people mistake what’s an immature bald eagle for a golden eagle.”
Golden eagles are slightly larger, more western-based raptors with a golden sheen across the head and neck of their dark brown bodies. They’re more likely to be found around hills and cliffs eating small mammals than around forests near fish-filled waters, making them unlikely to spot here. But during their winter non-breeding season, some have made an appearance this far east. Ridlbauer says a juvenile golden eagle was spotted at the Nachusa Grasslands several years ago as it was attacking a white-tailed deer.
“Golden eagles are extremely rare to find all the way out here,” says Olson. “But a few people and myself have been spotting a golden eagle here between Cherry Valley and Belvidere since early December this year, which is pretty incredible.”
As these species gain in numbers, they become more resilient to periodic diseases, loss of food and environmental changes, says Rasheed. Their thriving populations are sure to produce sightings in unlikely places.
A Single Species: Ospreys
The bald eagle’s success might come at another bird’s cost, though. The osprey, a type of hawk, is a remarkably unique raptor that lives and hunts in similar habitats as the bald eagle.
The osprey is known for its diet of live fish and ability to dive into shallow water to catch them. Its dark brown body and white head resemble the bald eagle, but the osprey also has a unique black eye stripe down the side of its face. It has developed adaptations in its feet, including gripping pads and unusual talons – with two toes in front and two in back instead of the standard three in front, one in back – to better catch its slippery prey. Ospreys battle the larger eagles for food and territory, but are regularly forced to drop their catch for eagles to steal in midair.
Despite a rebound from the days of DDT, ospreys are still endangered in Illinois.
“With all our river systems, there’s no reason why we shouldn’t have more ospreys here,” says Ridlbauer.
Another obstacle for ospreys is their nesting requirements. These birds build large stick-and-sod nests near water, but need to position them out of reach of raccoons and opossums, while remaining below threatening wind and winged predators. They often get into trouble by building nests on man-made structures, such as telephone poles and cranes. With the installation of more artificial nesting platforms, these birds could gain the stability needed to be delisted from the state’s endangered species list.
Fortunately, ospreys are having better luck in other areas and can be found on every continent except Antarctica. They are heavy migratory birds, and have been recorded to log more than 160,000 migration miles during their 15-to-20-year lifespan. Birdwatchers in Illinois have the best chance of seeing ospreys during fall and spring as they migrate.
The Fastest Birds in North America: Falcons
Northern Illinois hosts three types of falcons, which are distinguished by compact, powerful bodies, thin, tapered wings and long tails. These agile flyers quickly maneuver with remarkable speed and adaptations, making them one of the most admired and referenced birds. Yet, despite these similarities, their differences in prey and habitat have created variant rates of survival for the three species in our region.
“The American kestrel is the smallest falcon found in the Americas; it’s about the size of a blue jay or robin,” Rasheed says. “Unfortunately, they are one of the few birds that are in decline, and it primarily comes down to habitat. They need small stands of trees with open ground. Our prairies and grasslands are perfect for that. But when we started taking out the prairies with large-scale farming, the diversity of their prey decreased and, as a result, kestrels haven’t been able to adapt quite well.”
Even though kestrels have decreased in population nationally, it’s not uncommon to see these falcons in our region, says Ridlbauer. One’s best chance of seeing a kestrel year-round is while driving along rural roads with billboards and utility poles, where they perch while hunting, or seeing them in trees and bushes, where they roost. They like to nest in tree cavities or other protective structures, too. Although a strong and agile bird, the kestrel often falls prey to larger raptors.
Nicknamed the “sparrow hawk,” these small birds use a powerful hovering technique to go after insects and small mammals in grasslands and meadows. Like a hummingbird, they hold a position midair and survey an open area before swooping in for an attack. They’re one of the few birds with ultraviolet vision, which allows them to track prey by urine trails through long grass. All falcons have a sharp notch on their beaks, called a tomial tooth, that is used to sever the spinal cord of prey if they aren’t killed on impact.
“Another interesting fact about kestrels is that they’re one of the few raptors to have sexual dimorphism, meaning the female looks significantly different than the male,” Rasheed says. “It also makes them one of the most colorful raptors.”
Male American kestrels are noted for their slate-blue head and wings set against a rusty-red back and tail, while females have only warm red coloring. This also makes the kestrel distinctive from the next falcon in size, the merlin.
“Merlins are speed demons. As mostly bird eaters, they go after anything small that flies, so they’re broader and stockier than the kestrel. But they live in similar habitats,” Ridlbauer says.
These birds have a powerful build to carry out surprise attacks on their prey at incredible speeds.
“It’s a crazy thing to see them pursuing another bird because of the agility that they have. They’re not only dodging tree branches and other obstacles, but they’re targeting other flying birds as they gain on them,” Olson says. “These birds that hunt other birds can see things at a speed that we can’t even comprehend. It’s almost like they can see in slow motion.”
Our region is home to the Taiga merlin, which is a medium-dark bird with streaky coloration. Males are generally more of a gray color while females and juveniles are brown. Typically, the merlin stays in northern Illinois for only six months at most, if it comes to breed during the summer months. Otherwise, it just migrates through, making it a rare find in our region.
The largest and fastest of our falcons is the peregrine, and these birds have had a surprising recovery path from the days of DDT. Originally nesting on cliffs and high vantage points, peregrine falcons hunt through spectacular stoops, or vertical dives, to kill and capture other birds.
“This is a bird that can literally climb 9,000-10,000 feet up, if not higher, to go above their prey. They then come down at high speeds of up to 200-250 mph,” says Ridlbauer. “They actually clocked one of these peregrines at 289 mph.”
A peregrine balls up its toes to brace for impact, when it hits the back of its prey’s neck and knocks it out of the sky. If it’s not an instant kill, it uses its tomial tooth to finish the job.
“I know of a peregrine that literally hit a pigeon so hard that the heart of the pigeon was found elsewhere from the rest of the bird on the ground,” says Ridlbauer.
The peregrine falcon has been recorded to eat an enormous variety of birds, with up to 450 species documented, from hummingbirds to cranes. In Illinois, they’re most likely to eat pigeons – for a specific reason.
“Peregrine falcons like nesting and hunting from cliffs, which are in southern Illinois. So, traditionally, that was the only place you could see peregrines,” says Rasheed. “When people started to help to rebuild peregrine populations after that whole DDT debacle, they were carefully locating nesting pairs and monitoring them. But then they started thinking, ‘Why don’t we bring them to the cities and release them there?’ They thought they’d be much safer there away from wild predators. With downtown Chicago being full of skyscrapers, which look exactly like cliffs to these falcons, it was almost like their natural habitat. The city’s pigeons then became almost perfect prey for them. It all just clicked.”
Today, there are more peregrine falcons in cities like Chicago than in natural areas, even more than before DDT. Rasheed remarks on the irony of the situation – how this destructive environmental mistake in the 1970s unintentionally led to the ultimate growth of the peregrines. While it’s a lucky outcome for this bird, Rasheed hopes the peregrine population encourages the positive connotation of the term “urban jungle,” or the idea that humans can responsibly live among thriving native creatures, even in cities. It has become a priority for these raptor centers to educate residents on the value of these animals and their effect on the surrounding landscape, including humans.
“I keep telling people that it’s really important for us to be aware,” says Rasheed. “Because the next DDT could be out there right now and we haven’t realized it yet.”
About the Photographer: David C. Olson maintains a studio and gallery just off I-90 in Rockford, at the Clock Tower Inn, 7801 E. State St. See more of his work at DavidOlsonPhotography.com.