Month: December 2024

Owls are found year-round in northern Illinois, and they come in several sizes and shapes and live in various habitats.  Owls found near urban areas are often active only in the evening or at night, making them elusive to find and observe their behaviors.  Native owl species have a highly varied diet, hunting almost every animal smaller than themselves from insects and crustaceans to small mammals, reptiles, and amphibians.  Some of their unique characteristics and places to find them are highlighted below.

^{Barn Owl, Tyto alba pratincola, by DonArnold, JSNM Museum and Great Horned Owl, Bubo virginianus, by DonArnold, JSNM Museum}

Great Horned Owls, Bubo virginianus, live in every habitat across North America, Central America, and parts of South America.  Standing two feet tall with mottled brown and gray feathers, they are well camouflaged during nighttime activities.  Their ‘horns’ are actually feather tufts sticking out above their ears, which may enhance hearing and make them easy to identify.  Look for them at dawn and dusk in tall trees standing on the edges of open spaces.  The Barn Owl, Tyto alba, hides in tree hollows or dense vegetation during the day, coming out to hunt at night.  They are a foot tall with a distinct white face and chest and pale brown and gray backs.  A high energy lifestyle requires them to eat more than other animals their size.  They are mostly found in open fields near wooded areas that provide diverse habitat for prey.

^{Barred Owl, Strix varia by DonArnold, JSNM Museum; Northern Saw-whet Owl, Aegolius acadicus by DonArnold, JSNM Museum; Short-eared Owl, Asio flammeus by DonArnold, JSNM Museum}

Three owls are daytime hunters, but not often found in urban areas.  Barred Owls, Strix varia, have small territories, covering no more than a few square miles during their lifetime.  They are brownish gray with dark stripes on their bellies.  They hunt during both daytime and nighttime and have been known to eat carrion if it’s easily available.   Look for them in wetlands with mature woodland cover nearby.  Another daytime hunter, the Short-eared Owl, Asio flammeus, is an abundant species standing about a foot tall and known by its brown speckles covering a cream colored undercoat, with a barred tail and wings and a light belly.  Their diet is similar to other owl species, but they may also hunt rabbit and weasel.  Look for them flying low to the ground in open areas including grasslands, meadows, and wetlands.  The Northern Saw-whet Owl, Aegolius acadicus, is only six inches tall, with a round, light colored face and belly streaked with brown, and a brown back with light spots.  They are highly maneuverable and can easily hunt in small spaces.  These owls have incredibly sharp talons and beaks, and they are able to take down prey larger then themselves.  They favor dense, mature forests, especially those containing conifers.

^{Eastern Screech Owl, Megascops aslo, by DonArnold, JSNM Museum; Long-eared Owl, Asio otus, by DonArnold, JSNM Museum}

The next two species are smaller, nighttime hunters, often found in urban areas.  The Eastern Screech Owl, Megascops aslo, stands eight inches tall and is all grey or slightly reddish-tinged.   This owl species has also been observed feeding on fruits and berries.  They are found in forests, wetlands, and urban neighborhoods with mature trees.  The Long-eared Owl, Asio otus, one of the most abundant owl species world-wide, is a foot tall, with black and brown plumage.  They hunt by stealth, waiting on a perch for prey to come close, then pouncing.  Look for them in urban settings with large trees and in many state park areas.  

A winter only resident, the Snowy Owl, Bubo scandiacus, stands two feet tall with distinctive, almost pure white plumage.  They are active both night and day, and can cover large distances in their daily hunts.  A large, ferocious hunter, they can take down prey larger than themselves.  They are found in a widely diverse set of habitats including open grassland, wetlands, shorelines, and several of our area’s larger airports.

We have many owls on display at the Jurica-Suchy Nature Museum.  Come in and learn from our newest Illinois In Winter display or our owl and other raptor displays.  We are closed for the holiday break, but consider visiting us as we reopen for the Spring semester in early January.  Check out our schedule and make a reservation to come see us at https://ben.edu/campus-links/jurica-suchy-nature-museum/.

Owls are a type of raptor, a bird of prey with forward-looking eyes, large talons, and hooked beaks.  Raptors are known for having the best vision of any animal, and they are skilled hunters found across all  habitats.  Other raptors include hawks, eagles, falcons, kites, and vultures.  There are nineteen owl species native to North America, and eight of them are regularly found in Illinois. 

^{Pictures clockwise above: Black Kite by Martine LIU, Getty Images; Golden Eagle by Timu Abasov, Getty Images; Red-tailed Hawk by BrianEKushner, Getty Images; Turkey Vulture by James Opiyo, Getty Images; Peregrine Falcon by Harry Collins, Getty Images Pro}

Owls have large eyes that look forward and provide a wide angle of view.  Their binocular vision helps these birds easily spot prey and accurately judge distances when either stationary or in flight.  An owl’s eyes cannot move within the eye socket, so the owl must move its entire head, which is capable of rotating 270 degrees to see completely around itself.  Their vision is extremely sensitive to light, and they are capable of hunting when conditions are quite dark. 

The feathers on their round faces help to direct sound into their ears, which are located on either side of their head.  Their ears are small openings covered by feathers that can enhance and separate sound waves, working like binocular vision, allowing the bird to identify how far and in which direction a sound originates.  Their enhanced ability to detect movement around themselves, coupled with excellent vision, makes these birds of prey one of the top hunters in their environment.

^{Owl beak closeup by GrahamH, Pixabay; Snowy Owl talons by WWing, Getty Images; Black fur in owl pellet by Justin Smith, Getty Images}

Sharp beaks and talons are used to capture and hold prey, and to easily tear apart meat.  All raptors have eight toes ending in a talon, or sharp claw, made of keratin.  Owl talons are long and curved and are used to easily grasp a branch or a prey animal.  Their beaks are made of bone covered with keratin, with very sharp edges.  They have no teeth to chew food, and they eat their prey whole or in large chunks.  Whatever is not digestible, including bones, fur, and feathers, is compressed into a wad in the owl’s mouth and spit back out as a pellet.  An Investigation of owl pellet contents can reveal the prey the owl is currently eating.

Owls have fringed outer edges to their flight feathers that deaden almost all sound made while flying, making it difficult for prey to detect an owl coming for them.  An owl’s large, rounded wings and short tail provide great maneuverability while flying.  Their excellent vision, hearing, and flight maneuverability allows them to hunt at night in areas with numerous obstacles including woodland and urban areas.

In the next blog, I will take a closer look at the owls in Illinois.  At the Jurica-Suchy Nature Museum, we have several displays that highlight the various characteristics of owls and other raptors.  We are closing for the holiday break, but consider visiting us as we reopen for the Spring semester in early January.  Check out our schedule and make a reservation to come see us at https://ben.edu/campus-links/jurica-suchy-nature-museum/.