My husband called me to the kitchen door. Putting my ear to the storm door, I heard the low, resonant “hoo, huh-hoooo, hoo, hoo” of a Great Horned Owl. That haunting sound marks the beginning of the courting season for owls around here. The breeding season for the Great Horned Owl begins earlier than other owls, mating and nesting in January and February. Others will be heard courting from March through May.
The one we heard sounded as though it was nearby and I worried that if I opened the door, its sensitive ears would register the sound, making it fly off. We strained to see the shadowy shape silhouetted against the limbs outside the dark window. But this time, no luck. I opened the door just a crack, heard a few hoots and off it went.
By happy chance, the next day I learned about a course on owls from Cornell University Lab of Ornithology Bird Academy. What luck! I spent some quiet, snowy hours learning about these highly skilled, powerful predators. I thought you might be interested, too. I’ll only be able to offer the highlights here, or course. If owls intrigue you, The Cornell Bird Academy class, “The Wonderful World of Owls,” is thorough and is packed with helpful recordings, photos and videos of owls all over the world.
I’ve only succeeded in photographing one owl in the wild, but luckily, my friend Bob Bonin from our Wednesday bird group generously shared many of his impressive owl photos. So you’re in for a visual treat. Thank you, Bob! I’ve supplemented with photos from generous inaturalist.org photographers and included links to owl calls from Cornell’s All About Birds website, because we’re all more likely to hear owls than see them!
The Special Abilities Owls Use to Rule the Night
Owls live on every continent except Antarctica and in a variety of habitats – deserts, the arctic, the tropics, grasslands, and forests. Though some hunt in daylight or as the sun is rising or setting, owls are best known for hunting at night. Owls may nest in tree cavities, nesting boxes, on the surface of the tundra, in former nests of other birds, and some even burrow underground. Here I’m just exploring the five of the most common ones we might see, or more likely hear, in our region. However, most of the 234 species of owls share some special gifts that allow them all to be formidable hunters.
Amazingly Accurate Binocular and Peripheral Vision in Low Light
Owls are the only birds that can catch their prey in the dark. They can’t see when it’s completely dark, but they can in very little light. How? Well, their eyes are large to begin with and in the dark, the pupils expand to fill almost the whole eye surface. Like other nocturnal creatures, owls have the advantage of “eye shine” (tapetum lucidum) which you’ve probably noticed in the eyes of your cat, dog, local raccoon or possum. If light hits them in the dark, their eyes look like glowing red or green circles. Light hits the rods in their retinas (the cells for low light) on the way into the eye, is reflected back by special cells behind the retina and hits the rods again on the way out. That bounce amplifies the light for better night vision.
Feathers make owls’ eyes seem to be staring forward like ours, but their eyes are actually set very slightly to the side, allowing them more peripheral vision than we humans have with our straight forward eyes. But because their eyes are only slightly off to the side, the visual fields from each eye can overlap, providing them with accurate binocular vision and depth perception when catching prey.
Our eyes, of course, move in their sockets, so we get more peripheral vision than the birds with eyes on the sides of their heads. But owls can’t move their eyes; they’re fitted tightly into bony sockets. To look around, owls need to rotate their heads. Luckily, that’s easy for them, as it is for most birds. I’m sure you’ve seen geese turn their heads backwards when snoozing or preening. Owls have longer, flexible necks, too, having 14 vertebrae instead of ours with a measly 7. I can hear you exclaiming, “What? Owls don’t have long necks!” Aha! That longer, flexible neck is just hidden under a thick, rounded cloak of feathers beneath their large heads. They can’t turn their heads 360°, of course, even though it sometimes looks like they can. But they can easily reach 180° to look behind them as in the photo of the Barred Owl above – and a bit further at times to almost 270°!
Exceptional Ears Where You’d Least Expect Them!
Like most of us, you might have assumed those tufts on the head of some owls are ears. The host of the Cornell course, ornithologist Dr. Kevin McGowan, explained that the tufts on the Great Horned Owl, for instance, are just used for display during courting or confrontations.
Like us, owls do have an outer and inner ear. Have a look at this photo of a Barn Owl’s face (Tyto alba) taken by photographer Mark Greene at inaturalist.org.
That lovely heart-shaped disk is the Barn Owl’s outer ear. Our outer ears on each side of our head funnel sound to our inner ears, located inside our head. The owl’s facial disk does the same, functioning somewhat like a satellite dish bringing in a signal. The stiff, interlocking feathers of the ruff at the outer edge direct sound toward the openings of the inner ears. The inner ear openings are hidden under soft, feathers near the outside edge of each eye. What’s more, in most owls the inner ears are offset, one slightly higher on one side of the head than the other. This allows most owls (see the Saw-whet and Screech owls below) to more accurately locate sounds from above (avoiding predators) and below (finding prey). This elaborate arrangement permits owls to hunt in the dark by both sound and sight.
Those Powerful Talons!
All owls have four toes, two forward, two back, unlike most other perching birds who grip a branch with three forward and one back. The Great Horned Owl’s large feet end in large, sturdy talons that can close around prey which is generally rabbit-sized animals, like chickens, ducks, house cats, skunks, ducks, possums and the occasional rodent or frog. Owls that choose smaller prey have smaller feet and thinner talons. Owls usually eat the entire animal and a couple of hours later, regurgitate a pellet that contains the fur, bones and other indigestible bits. Pellets at the bottom of trees are a good sign that owls nest or perch there.
Almost Silent Wings in Flight
Owls navigate the landscape on wings that make almost no sound. What a great advantage for a hunter! The prey can’t hear them coming, and they can more clearly hear the prey. They accomplish this feat in several ways. Cornell’s Dr. McGowan explained that “Owls have relatively large, broad, rounded wings that produce a lot of lift for the size of the bird … This allows for slow flight, and slow flight is quieter than fast flight.” Think of the quick, noisy beats of a duck on takeoff. Secondly, owls evolved special feathers that keep the noise down. “The front edges of the outer wing feathers have a comb-like structure” which creates “a smooth flow of air over the wing, reducing turbulence and therefore noise.” The back edge of these feathers are fringed to do the same thing. Plus, the fine filaments on the velvety surface of an owl’s wings dampen the sound of feathers rubbing against each other. Wow! A flying predator with excellent sight and hearing maneuvering silently through the trees. That’s a formidable hunter!
Now, Let’s Meet – and Listen to – Some Local Owls
Great Horned Owl (Bubo virginianus)
Listen for the Hoot!: The Great Horned Owl Turn up your volume and click on this blue link from Cornell University’s Ornithology Lab. The clearest recording of this owl’s courting “song,” I think, is the first one, labeled “Song.” You’ll hear a call in the distance at first but at about 13 seconds, the louder ones begin. Great Horned Owls vocalize from mid-September to early April, but now is an excellent time to start listening because they’re in the breeding season.
The Great Horned Owl beyond our dark window hooted for the same reasons all owls call – to defend its territory or to court a mate. Great Horned Owls nest during January and February, the earliest of the local owls; others generally mate from March through May. Like most owls, they don’t build their own nests. Great Horned Owls nest in natural tree cavities and tall broken-off tree trunks, but they also take over big, flat nests high in trees constructed with bare sticks. As a result, they prefer last year’s hawk, crow, eagle or heron nests which are built just the way they like them.
Courtship by Great Horned Owls is quick and short on romance – a bit of bowing, hopping, occasional beak snapping, fluffing feathers, a mouse or some other bit of food given by the male to the female, some reciprocal hooting and that’s about it. Cornell’s allaboutbirds.org website has an excellent video of the brief mating of two Great Horned Owls. As you’ll see, it can be pretty perfunctory.
Generally, the female incubates during the day, the male at night for about a month. Like most birds, both adults must defend their eggs and nestlings from snakes, squirrels, chipmunks and other birds. Of course, these owls themselves can prey upon these creatures, as any harassing crow could testify!
The nestlings grow quickly, gaining weight and mobility within the nest for about 6 weeks. Adults spend arduous months feeding hungry owlets like the ones below that Bob Bonin saw peeking from the top of a broken tree. Such a great photo!
Between the sixth to eighth week, the fledglings come out of the nest and simply sit on branches waiting to be fed. It’s called “branching.” Bob caught this Great Horned Owl fledgling who looks like it’s waiting for its meal to arrive. What a glare, eh?
According to Stokes Guide to Bird Behavior, Vol 3, the fledglings start attempting to fly at about 9-10 weeks. They practice flying and hunting and at about 5 months are ready to be on their own.
Barred Owl (Strix varia)
Listen for the Hoot!: Barred Owls The Barred Owl courts in February or March but its hooting can be heard from January to mid-April. Its distinctive call described by Cornell Ornithology as “Who cooks for you? Who cooks for you-all?” is a memory aid that makes me smile. Its hoot is said to carry easily in the forest and I can believe that from the “song” recording at this link.
I’ll probably never hear a Barred Owl hoot in my neighborhood; they stay clear of the territory of any Great Horned Owl, their most dangerous predator. Barred Owls are year ’round residents, though, and most of them stay in the same area year after year, sometimes re-using the same nest. In winter, females in rural areas may stay on their territory while the males venture into cities and suburban areas seeking more food. So you might get lucky at your house or local park!
Barred Owls do most of their hunting during the night, but often they’re seen roosting during the day as well. They have smaller legs and finer talons than the Great Horned Owls (see photo below) because they generally eat smaller prey like mice, chipmunks, squirrels, sometimes frogs or other birds. Mates tend to roost together and Bob Bonin caught a fine photo of a pair doing just that. As is common in large birds, the female is the larger of the two.
Barred Owls move into the same sorts of nest that Great Horned Owls prefer. They are prey for larger owls and hawks, especially their eggs or nestlings. Sometimes the prey turns on them; small songbirds, crows and woodpeckers occasionally mob and harass them in order to protect their own nest or young. Once hatched, the Barred Owl nestlings remain in the nest for about 4-5 weeks before fledging, but young Barred Owls like the one below may not be fully on their own until the following fall. If this little owl fell from its perch, it would grasp rough bark with its beak and talons, flap its wings and walk up the tree!
Northern Saw-whet Owl (Aegolius acadicus)
Listen for the Hoot: Saw-whet Owls The Saw-whet Owl’s song sounds very much like a truck backing up, a long series of short beeps! Starting in late January, they can be heard “beeping” at the edge of a woods. Of course, they also use a variety of calls to communicate with mates, young and other owls. Some of those calls are very high and piercing! It’s been suggested that the owl’s name refers to the sound of a saw being sharpened on a whetstone. Check out the “calls” at the blue link above and you’ll see why that might be correct!
Saw-Whets are tiny, only 7-9 inches high and very fetching with their over-sized heads and yellow eyes. To avoid becoming prey from larger owls and hawks, they spend daylight hours in dense foliage, most often in evergreens, just as in Bob’s photo above. At night, though, they are efficient hunters. Their diet is mostly mice, especially deer mice, which carry the dreaded ticks that now infest our summers. So the Saw-whet’s diet has my approval. Saw-whets that migrate north to breed, however, may eat songbirds along the way. The slightly offset ear openings of Saw-whets allow them to accurately locate prey even in deep snow. They’ve been known to plunge into 18 inches of snow and emerge with a mouse! I’d love to witness that!
Saw-whets nest in tree cavities, most often those created by woodpeckers and flickers. The females incubate, while the males bring food. When the owlets reach about 18 days old and produce feathers, the female departs to roost elsewhere. The male continues feeding the young alone, though the older nestlings sometimes help feed their younger siblings. The female may mate again if the opportunity arises. Since these small owls are prey for so many creatures – squirrels, starlings, crows, hawks and larger owls, among others – producing more young is important for their survival as a species.
Eastern Screech Owl (Megascops asio)
Listen for the Hoot … or rather Screech! The most famous song of an Eastern Screech Owl sounds to me like a spooky, descending whinny. It’s the first recording at the link and is used most to defend territory. When communicating with mates or young, Screech Owls use a monotone of pulsing notes which you can also hear at the link. The “screech” is a shriek used when defending the nest or their young. Cornell provides no recording of that sound; maybe if you hear it, you’re running away! Screech owls fly at predators – and occasionally curious humans – who venture too close to their nests. Listen for Screech Owls from mid-January to the end of March.
The Eastern Screech Owl is a cosmopolitan bird in two respects. It can be found on farmland, in suburbs or in cities anywhere east of the Rocky Mountains. And its menu is cosmopolitan too. In summer, they feast on large insects like beetles, moths, crickets and grasshoppers along with mammals. In winter, they tend to exclusively choose animals, some as small as rodents, moles and finches, others as large as Bluejays, woodpeckers, rabbits and squirrels. They even snag an occasional bat as it flies by! They use a “perch and pounce” strategy, waiting for prey in their hole and then dropping down or swooping out at them.
Screech Owls also come in two “morphs.” The gray one above is most common, but lucky for us, Bob Bonin caught a photo of the red morph which makes up only about 15% of the population, according to Wikipedia.
In late winter, Screech Owl males tempt a mate by leaving food in a tree cavity, a natural one or one excavated by woodpeckers. Unlike most bird species, their holes are not just used for raising young. Screech Owls sleep and sun in their nest cavities during the day, feed in them to avoid predators and retreat to them in bad weather. Egg laying commonly begins in mid-April. Though Screech Owls are generally monogamous, males do occasionally have a second mate. According to Cornell’s allaboutbirds website, “The second female may evict the first female, lay her own eggs in the nest, and incubate both clutches.” Hmmph! The first female may look for another (ideally more faithful?) mate, since screech owls generally produce two clutches a year. About four weeks after hatching, the fledglings climb out of the hole using their beaks, feet and wings. A week or so later, they begin following the adults, but won’t disperse until late summer and generally move less than a mile way.
Snowy Owl (Bubo scandiacus)
Snowy Owls (Bubo scandiacus)
No hoots with this owl! Snowy Owls breed beyond the Arctic Circle so we don’t hear their courting or territorial voices beyond perhaps an occasional irritated clack of the beak. They do, however, show up in our area periodically in the winter looking for food. A common misperception, according to Cornell’s Dr. MacArthur, is that they arrive starving because of insufficient food in northern Canada and the Arctic. Oddly, it’s just the opposite!
Snowys eat lots of lemmings, their favorite arctic rodent that makes up about 90% of their diet when available. Somehow Snowy Owls adjust the number of eggs they lay according to the natural fluctuations in the abundance of lemmings. In years when lemmings are plentiful, the owls produce more young. With larger numbers of young, competition for prime feeding territory can get intense. When that occurs, some young owls with less ability to compete move down into Canada or Michigan to more easily find food in the winter. So these periodic “irruptions” as they’re called are caused by an abundance rather than a scarcity of food in the Arctic.
[A note: Contrary to popular myth, lemmings do not “commit suicide.” Some lemmings erratically migrate en masse when their population density gets too extreme. They can end up in dangerous situations if deep water or other obstacles are in their path.]
Snowy Owls are truly remarkable birds. They scrape their earthen nests out of the Arctic’s frozen tundra. And scientists are learning that, for reasons unknown, a Snowy Owl may breed one year in Canada and the next year in Siberia. They’ve evolved beautifully to cope with frigid temperatures. Their breasts, heads, faces and even legs and feet are heavily insulated with white feathers which camouflage them in their snowy landscape.
And think of this – in the deep, 24-hour darkness of an arctic winter, these birds forage in openings in the endless ice for seabirds. They plunge into the snow, or run across it to capture lemmings. Very few animals survive in such dark, frigid conditions and many of those that do are prey for magnificent snowy owls. So if you can, seek out these beautiful birds when they descend from the top of the world to feed before returning to their icebound homes.
Other Owls You Might Find in Our Region
I’ve only covered five owls that appear in our immediate area. Here are four others that live in Michigan year ’round or come here periodically: 1) The Long-eared Owl (Asio otus) spends most of its time farther north and breeds at the tip of Michigan’s “mitten” or in the Upper Peninsula. It camouflages during the day in dense foliage, so I’m so glad Bob Bonin spotted one! 2) The Short-eared Owl (Asio flammeus) lives here year ’round and generally breeds in the upper half of the “mitten.” It can be seen at dawn and dusk flying low over fields or grasslands. 3) The Barn Owl (Tyto alba) seems to be less common in Michigan than it once was, probably caused by loss of habitat. We don’t have the barns and haystacks of the past. It can eat 3-10 mice per day and can catch them in very low light. 4) The Great Gray Owl (Strix nebulosa) lives year ’round in Canada and Alaska, but occasionally ventures into northern Michigan during the winter months. I love its shocked expression. [Click on photos to enlarge.]
Tips for Seeing Owls
Cornell’s excellent class, The Wonderful World of Owls, ended with some useful tips that I hope to use before the winter ends.
- Learn Their Sounds – Our odds of identifying a nearby owl with our ears are much greater than our odds of seeing one.
- Know Owl Habitats – I’ve provided some info on the habitats of common owls in our area. If you live elsewhere, consider taking Cornell’s course; they cover owls all over the country and world. Or consider exploring Cornell Ornithology’s ebird.org/hotspots to find out which owls – or other birds – have recently been spotted near your area or wherever you’re traveling. Citizen scientists around the globe regularly report to eBird on the birds they see.
- Learn the Time of Day When the Owl You’re Seeking is Most Active – For instance, Short-eared Owls are most often seen at dusk, which is the beginning of the day for them.
- Go Owling When the Moon is Full or Nearly Full – We increase our chances of seeing an owl when the moon is full on a clear night, especially if snow is reflecting the moonlight. Also there’s some evidence that owls hoot more in bright moonlight.
- Avoid Windy Nights – Owls don’t call much if the wind is blowing. Possibly they’ve learned over the eons that their hoots are more difficult to hear in a stiff wind.
- Winter is a Great Time for Owling – Owls often roost on branches in the weeks before and after their nesting season. So now is a great time. Seize the day!
- Look for Pellets Below Trees or “Whitewash” on Tree Trunks – Those are good signs that owls roost or nest there.
- Listen for the Frantic Calls of Mobbing Birds – If you hear a whole group of birds screeching at one time, look around. There’s a good chance that an owl in the area has set them off.
Our Fear of and Fascination with Predators
Few things are more intriguing on a winter night than the haunting song of an owl. They sound like something wild, something alien. Our instincts sometimes are to tame that wildness, to reassure ourselves that these fierce predators of the night are harmless, at least to us. In ancient mythologies or in children’s stories, owls are often associated with wisdom and intelligence. As a child, my younger brother played with an owl puppet and a child I’m fond of now keeps company with two toy owls. We learn early to love owls.
But as an adult, I’m glad to learn of the skillful fierceness and lethal power of a hunting owl, too. I want to remember that death in nature is rarely random violence. Nature accepts death as necessary to survival. Owls kill to eat or to defend the next generation of owls. Wild predators – the ones humans fear like snakes, coyote, wolves or sharks and the ones we admire like dolphins and whales – all must kill to eat and raise their young. And of course, we humans do pretty much the same, except that most of us rely on other humans to do the necessary ending of another life.
I’m trying to deepen my understanding of nature’s undeniable linkage between death and life. Its network of intricate relationships, worked out over eons, requires death to protect and sustain life. Maybe because I’m aging, I’m trying to integrate that acceptance of death into my love for nature, so as not to romanticize it. I want to love all of it, the glorious and the grim, as part of the natural order. Maybe that way, I can better accept that in my own human life as well.