The owls of Will County

_{|  Story by Laura Kiran  |}

_11/16/2018

Down through the centuries, owls have been viewed as mesmerizing creatures, often described as wise, serious and even magical. While more than 200 species of owls are reported to exist worldwide, it is the elusiveness of this member of the raptor family that contributes to its long-held air of mystery.

“In comparison to other birds, owls probably wouldn’t rank as the wisest, even though that is the stereotype,” said Bob Bryerton, interpretive naturalist at the Forest Preserve’s Plum Creek Nature Center in Crete Township. “However, they are incredibly adaptable and have amazing instincts. And they are definitely hard-wired to work within the environment to get what they need to survive.”

Owls’ evasive nature, he explained, centers in part around the need to stay undercover for protection. “Owls are not buddies, so a larger owl will kill a smaller owl if given the opportunity. Also, because owls will eat the young of other bird species, most birds do not like owls. And birds, especially crows, will mob them and can actually kill an owl if there’s a large enough group. So, generally, they tend to stay hidden and can camouflage themselves pretty well.”

Owls are also seldom in the public eye due to their hunting patterns, Bryerton said. Because owls and hawks have the same food preferences, hawks tend to hunt during the day and owls at night to reduce the competition. “So hawks get the day shift, and owls get the night shift,” Bryerton explained. Bad luck if you’re a mouse, he added, because you don’t get a break. 

In all, Will County is home to eight of the 19 species of owls found in North America. These include the:

• Barn owl
• Barred owl
• Eastern screech owl
• Great horned owl
• Long-eared owl
• Northern saw-whet owl
• Short-eared owl
• Snowy owl

Year-round Residents

Barn owls

With their white, heart-shaped faces, pensive dark eyes, and light brown feathers dotted with even darker spots, barn owls are possibly “the most widespread of all land birds, found on every continent except Antarctica and on many island groups,” reports the Cornell Lab of Ornithology. Their facial disks hide their ears, which are known to be extremely sensitive. Experiments have shown that they can locate and catch prey in complete darkness, using their highly acute sense of hearing. 

Weighing 14 ounces to 1.5 pounds, barn owls are medium in size compared to other owls, and are approximately the size of a crow. They eat rodents and a variety of small mammals, lizards and birds. Unlike other owls, barn owls do not hoot. They instead deliver a screeching hiss.   

While found globally, these owls are now an endangered species in Illinois due to perhaps a decline in nesting and foraging habitat. According to the Illinois Raptor Center, barn owls were common in Illinois until the 1960s and could often be seen nesting in abandoned barns and other buildings when the cavity of a dead tree or a dense group of trees was not available. 

“Barn owls are smaller so they can camouflage themselves fairly easily,” Bryerton said. “It is very possible that barn owls exist in our preserves, but they’re hard to spot.”

Barred owls

Larger than a barn owl – somewhere between a crow and a goose, according to Cornell Lab – barred owls have dark brown eyes along with plumage that forms brown and white bars. According to Bryerton, this owl takes up residence in lowland areas near creeks and wetlands, and is well known for its call, “Who cooks for you? Who cooks for you, all?”

Weighing up to 2 pounds, barred owls eat rodents, rabbits and birds as well as frogs and snakes. They swallow their prey whole or in good-sized pieces if the animal is large, and may store their prey until they’re ready to feed. According to Cornell Lab, barred owls usually nest in the natural cavities of large trees, about 20-40 feet off the ground, but they may also use stick platform nests built by other animals. Barred owls may prospect a nest site as early as a year before using it, Cornell Lab also reports.

“Any preserve that has a river corridor or lowland area would have barred owls,” Bryerton said. “Goodenow Grove Nature Preserve, Hickory Creek Preserve and McKinley Woods are just some of our preserves that barred owls call home.”

While they may look about the same size as the great horned owl – which can weigh up to 5.5 pounds on the high end – they cannot compare to the great horned’s strength. According to the Illinois Raptor Center, barred owls possess smaller talons, are only a fraction of the weight, and in comparison are made up mostly of feathers!

Eastern screech owls

The screech owl can be found in most of Will County’s forest preserves unless the land is wide open, Bryerton said. In fact, east of the Rockies, they can be found wherever there are trees, according to Cornell Lab. This pint-size owl weighs between 4 and 9 ounces, is mostly gray or reddish-brown in color and is about the size of a robin. 

“These owls should be everywhere,” Bryerton explained, “but because they’re so small, you don’t really get to see them. And they need a place to hide because the bigger owls will hunt them.”

 

And hide they do, in nooks and crannies of trees, according to Cornell Lab. In fact, the screech owl makes its home in empty tree cavities usually deserted by woodpeckers or squirrels or naturally made by tree rot. These owls don’t make a nest, but instead rely on whatever natural materials exist at the bottom of the cavity.

Their calls can range from an even-pitched trill to a whinny, and their a diet is diverse, consisting of small rodents, insects, earthworms, frogs, lizards, and even songbirds. An excellent hunter, the screech owl is adept enough to sometimes feed on bats and has been known at times to eat other screech owls. 

Great horned owls

The great horned owl is the largest owl species in our area, and is also one of the top predators within its habitat. It is capable of taking down large prey, including other raptors and some decent-sized mammals such as skunks. 

When people think of the stereotypical hoot owl, it’s the great horned owl that comes to mind, Bryerton said. According to Cornell Lab, the great horned owl announces its territory with deep, soft hoots in a stuttering rhythm and snaps its bill in response to stressful conditions or a disturbance. Great horned owls have a blend of brown and white feathers, and striking yellow eyes.  

Weighing between 2 pounds and 5.5 pounds, this owl can be found locally in wooded areas near open fields. Bryerton said great horned owls reside in many of Will County’s forest preserves. However, this owl’s habitats range from forests, swamps and deserts to tundra and tropical rainforest. According to the National Audubon Society, they can also be found in cities, orchards, suburbs and parks.

 

“Great horned owls are tough critters,” explained Bryerton. “They choose to raise their babies in February. While most animals are waiting for warmer weather, this owl figures ‘Hey it’s the dead of winter, why not?’ So they’re resilient.”

Northern saw-whet owls 

The northern saw-whet owl is rarely seen in Illinois. But when they are reported, they are usually found in the northern part of the state. Like the screech owl, they are small in stature and weigh between 2 and 5 ounces. “Saw-whets are also about the size of a robin,” Bryerton said. “I’ve only seen one of these owls in the wild ever, and there’s not a ton known about them. They camouflage themselves really well and tend not to move around a lot.”

The northern saw-whet has yellow eyes and is mottled brown in color. It has a white face with white streaks on its head. It is believed this owl may have been given its name because its call sounds like a saw being sharpened on a whetting stone. 

Its main diet consists of mice, according to Cornell Lab, which states that the saw-whet will often eat adult mice in pieces, splitting up its catch between two meals. Also, like the screech owl, the saw-whet is a cavity dweller. 

Their secretive nature leads some bird-watchers to believe they may be more common than originally thought, the Illinois Raptor Center reports. 

Short-eared owls

The short-eared is an owl that you might actually see hunting during daylight hours as they are reported to be most active at dawn and dusk. This prairie owl prefers grasslands and open areas, perching low in trees or on the ground. “While you’re more likely to see the short-eared during the winter right before sunset, they are here year-round,” Bryerton said. “However, I’ve not seen these owls in our preserves a lot. Kankakee Sands Preserve might be a likely spot for the short-eared owl to reside.”

Weighing between 7 ounces to just over a pound, this owl’s feathers are a blend of browns and white. Their yellow eyes are encircled in black, and their faces have almost a catlike appearance. The ears mentioned in their name are often difficult to spot, and actually aren’t ears at all, but tufts of feathers used for camouflage.

The short-eared owl’s diet consists of mostly rodents, but can also include other small mammals as well as birds. Equipped for hunting open expanses, this owl flies low over short vegetation sometimes in an erratic pattern. While not extremely vocal, short-eared owls may bark, scream or whine when defending their nests and offspring, Cornell Lab reports, adding that females sometimes utter chicken-like clucking sounds.

This owl species nests on the ground, shrouded by grasses and other vegetation. A geographically widespread bird, the short-eared was listed as a “common bird in steep decline” on the 2014 U.S. State of the Birds Report, mainly due to habitat loss.

Winter Visitors

Long-eared owls

Like their short-eared brethren, long-eared owls prefer to forage over grassland areas for small prey. But unlike them, they only make Illinois their home during the colder months. According to Cornell Lab, these owls “roost in dense foliage, where their camouflage makes them hard to find.” In winter, they tend to roost in large numbers in forested areas. So if you’re fortunate to see one, you will most likely see others, Bryerton said.

While similar in weight, length, eye color and markings to short-eared owls, the long-eared owls can probably be most readily differentiated – as the name suggests – by the more distinctive tufts of ear-shaped feathers on top of their heads. They have orange or light brown faces without the telling black markings that circle a short-eared owl’s eyes and are reported to be more vocal than the short-eared, having a collection of hoots, squeals, barks and other noises. In addition, they seldom hunt before dark.

Their diet includes mice, shrews, young rats and rabbits. Their hunting technique compares to the short-eared owl in that the long-eared flies low above open areas in a back-and-forth pattern. These owls usually reside in nests abandoned by other birds, but are sometimes known to raise their young in cavities of trees, in abandoned squirrel nests or on the ground, the Cornell Lab reports.

While long-eared owls are thought to be fairly common throughout the United States, they – like the short-eared owl – are believed to be in decline due to habitat loss. They were until recently included on the Illinois state endangered species list. According to Bryerton, the long-eared aren’t seen often in Will County forest preserves. But whether that’s because they actually aren’t roosting in the preserves or simply aren’t detected there remains unknown.

Snowy owls

The sighting of a snowy owl is usually a special treat for birders and non-birders alike in this part of the country, due to their irregular appearance here in winter. According to Bryerton, snowy owls are irruptive, showing up in larger numbers some winters but not others. “There are usually a few every year,” he said of the yellow-eyed raptors, “but some years they arrive in greater numbers. The cause of these irruptions is not entirely understood, but it’s believed that it has to do with thriving prey populations. When there are more rodents, snowy owls have more young because food is plentiful.”

By weight, snowy owls are the largest North American owl species. Most weigh between 3.5 and 6.5 pounds. Snowy owls have white feathers, with a mix of black and brown markings on their wings and body. According to Cornell Lab, female snowy owls can have a denser mix of these markings, giving them a salt-and-pepper look. Males tend to be lighter in color in comparison and actually become paler as they age.  

About the size of a crow, snowy owls nest on the ground and can be found near shorelines of lakes and in open fields. “They breed in the arctic tundra where there aren’t any trees,” Bryerton explained, “so they don’t roost in trees and stay relatively near to the ground. You might find them on fence posts along an open field or even near shopping centers because there’s open space with usually a retention pond. Snowy owls are also active during the day since in the tundra there are no nighttime hours in the summer.” Last year, a snowy owl was sighted near Riverview Farmstead Preserve in Naperville. 2017 marked an irruption year for this species.

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A snowy owl’s diet can range from rodents, rabbits and squirrels to wading birds, ducks and even geese. On the tundra, they mainly eat lemmings, but sometimes will switch to ptarmigan and waterfowl, Cornell Lab reports. Snowy owls give low, raspy sounding hoots, but they can also whistle and hiss in defense. Like most owls, they are tenacious and have been known to dive-bomb and strike at species much larger than themselves when feeling threatened. Reports have included an attack on a pair of arctic wolves and even clashes with humans. Snowy owls are considered to be a species in decline. In 2016, they were listed on the State of North America's Birds' Watch List.

Overall, Bryerton said winter provides a great opportunity to spot one or more of these owl species. “If you’ve always wanted to see an owl,” he said, “winter is a good time of year to start. The fact that it’s getting darker sooner, we tend to run into them a little more because our active time is overlapping with their active time. So you don’t have to stay up very late to spot one.”