Owls

Facts about Owls

Owls are birds from the order Strigiformes, which includes about 200 species worldwide, 16 in Canada &15 in British Columbia. They are mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers adapted for silent flight. Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish. They are found in all regions of the Earth except Antarctica and some remote islands.

What makes an Owl an Owl?

Special Feathers
Owl flight feathers are soft with a comb-like leading edge that gives them a whisper silent flight.

Strong Talons
Unlike most other birds, owls have two toes pointing forward and two toes pointing back. This gives their large, strong feet and needle-sharp talons extra strength in holding prey with a vice-like grip.

Strong Beak
Razor sharp mandibles that help them tear flesh of the prey. They attack with their feet and sharp talons, but rip up prey with their beaks. Most owls swallow small prey such as mice whole.

Pellets
Undigested fur, feathers and bone are molded into pellets in an owl’s stomach and coughed up at day roosts. They can vary in size and colour depending on the owl species and the prey. Pellets yield valuable information about the prey of owls, since you can identify animals by their bones—and sometimes even tell whether they were male or female, old or young.

Branching
Many young owls will leave the nest site as soon as they can stand on their large fast-growing legs, before they can fly properly. At this stage they occasionally fall to the ground, where they are at risk from predators. Young owls are tended by their parents longer than most birds since it takes time to develop the hunting skills necessary to survive on their own. Most of them are independent by the end of summer, but young Great Horned Owls can sometimes be heard begging for food in early winter!

Age
Smaller species such as Northern Saw-whet Owls normally live for 5 to 8 years in the wild, but larger species such as Great Horned Owls can survive for 25 or more years. All species will survive longer in captivity; perhaps double the life-span of wild birds.

Size
Unlike most birds (but like hawks and eagles), female owls are almost always larger than males. So if you see two owls sitting side by side, the big one is the female. But although males are smaller, they have deeper voices when they hoot! Young owls (and young birds in general) are as big as they are ever going to be by the time they can fly.

Sense of Smell
Most birds, including owls, have a rather poorly developed sense of smell. This might explain why Great Horned Owls don’t mind hunting skunks!

Eyesight
Owls have large, tubular eyes with round lenses, making them twice as sensitive as those of humans in low light situations, but the design that accomplishes this means their eyes lack the keen resolution typical of day-hunting raptors such as hawks and eagles. During the day, their visual acuity is about five times lower than humans.
Owl eyes are placed facing forward on large, flat facial disks, giving them a human-like appearance that differs from most birds. This gives them some binocular vision so they can judge distances, but forces them to turn their heads to look around, since, like most birds, owls cannot move their eyes in their sockets. Fortunately, like all birds, owls have long and flexible necks, so they can turn their heads as much as 270 degrees, compared to the 180 degrees of the average human. Unlike most birds, owls have a very imperfect ability to distinguish colours, since their retinas are dominated by rod cells, which are very sensitive to light but cannot distinguish colour. A protective translucent third eyelid, called the nictitating membrane, protects they eyes from being scratched as they fly through grass and branches.

Exceptional Hearing
Most owls detect and catch their prey primarily by sound. Their saucer-like facial discs are their external ears, directing sound towards the large ear openings on the side of the head. Some owls have asymmetric ears—being shaped differently on the right and left side. This allows them to detect exactly where a sound is coming from in all three dimensions, unlike the two-dimensional hearing of most animals. This lets them catch rodents under the snow—and Great Gray Owls often catch pocket-gophers in their tunnels just under the surface of the ground.

Markings
Most owls roost close to the trunk of a tree. The perch combined with their shape and mottled grey-brown coloration camouflages them well. Those species with “ear” tufts will often raise them in this situation, making them look more like a broken branch than a bird.

Eggs
All owls lay very round, pure white eggs.

Sounds that Owls Make
All owls have species-specific calls that they use in courtship or to mark their territory; Most of these calls have a hollow hooting quality, but the calls of some small owls are more whistle-like. Other calls are used to simply let other members of their species—usually their mates or young—know where they are. All owls have alarm calls, usually have a sharp, barking quality, to warn others about the presence of predators or other danger. Juvenile owls give distinct calls when hungry to let their parents know where to bring food—these usually have a hissing, rasping or screeching quality.

Value to Mankind
Owls are essential in controlling rodent populations. Some species eat a variety of insects that are considered pests. Other species feed on larger mammals such as rabbits or skunks. Healthy owl populations are a sign of a healthy ecosystem.


Reference Library – Owls

www.birds.cornell.edu
Cornell University Lab of Ornithology has kindly provided links for greater detail on each bird listed below. Click on the link to get specific information on identification, habitat, sounds & much more.

Small Owls

Flammulated Owl(Otus flammeolus)
Flammulated Owl

Total Length: 15-18 cm
Wingspan: 36 cm

Very small owl with mottled grey and rust markings, small “ear” tufts, short tail, dark brown eyes. Found in open, older forests of Douglas-fir and Ponderosa Pine.

Call a deep, soft ‘boop” or ‘boo-boop” repeated at intervals of 2-3 seconds.

Diet is almost entirely moths, crickets and other insects; nests in old woodpecker holes. Present from early May to September-October; migrates to Mexico in winter.

Cornell Lab: Flammulated Owl

Northern Pygmy Owl (Glaucidium gnoma)
Northern Pygmy Owl

Total Length: 17-19 cm
Wingspan: 38 cm

Very small owl with yellow eyes and bill, relatively long tail and large feet, black spots on the nape of the neck that mimic large eyes. Pygmy-owls are active during the day, hunting small rodents, birds, and insects. They are aggressive hunters, occasionally taking prey larger than themselves.

Nest in coniferous forests; some descend into rural and suburban areas in winter. They are non-migratory and nest in tree cavities.

Call is a hollow, whistled kook, repeated once every two seconds, becoming a rapid trill when agitated.

Cornell Lab: Northern Pygmy Owl

Northern Saw-whet Owl (Aegolius acadicus)
Northern Saw-whet Owl

Total Length: 17-20 cm
Wingspan: 53 cm

Small owl with proportionately large head, yellow eyes, and no ear tufts.

Adults have streaked breasts; young have solid brown breast and head.

Found in all forested habitats where cavities are available for nesting. Present year-round, but many birds at northern end of range move south in winter. Highly nocturnal, they hunt deer mice and other small rodents, occasionally birds and large insects.

Courtship call of male a monotonous series of short whistles repeated twice per second. Agitated birds give sharp, rasping calls or cat-like meows.

Cornell Lab: Northern Saw-whet Owl

Western Screech-Owl (Megascops kennicottii)
Western Screech Owl

Total length: 21-24 cm
Wingspan: 53 cm

Small-medium sized owl; mottled brownish-grey, yellow eyes, “ear” tufts.

Strongly tied to streamside riparian woodlands of cottonwood, birch and aspen. They are nocturnal and non-migratory, with a broad diet that includes rodents, small birds, small fish, large insects, worms, crayfish, scorpions, reptiles, and amphibians. Call is a series of whistled hoots that speed up like a ‘bouncing ball”; also a double trill. Screech owls do not screech (a screeching owl is usually a young Great Horned).

Cornell Lab: Western Screech-Owl

Boreal Owl (Aegolius funereus)
Boreal Owl

Total Length: 22-27 cm
Wingspan: 55-62 cm

Small-medium sized owl with large round, white face framed in black, charcoal cheeks. Young are solid chocolate brown.

Call a deep, soft ‘boop” or ‘boo-boop” repeated at intervals of 2-3 seconds.

Found in subalpine and boreal spruce forests, nests in tree cavities. They are nocturnal that prey primarily on voles, large insects and small birds.

Male’s courtship call is a high-pitched, rapid series of whistled hoots that rises and falls in pitch; other calls include a sharp “skiew” and a nasal “mooo-a”.

Cornell Lab: Boreal Owl

Medium Sized Owls

Long-eared Owl(Asio otus)
Long-eared Owl

Total Length: 35-40 cm
Wingspan: 90-100 cm

Rather slender owl with long wings, yellow eyes, greyish plumage, rust-coloured facial disc, and long “ear” tufts placed close together near centre of head.

Found in open forests or deciduous groves in grasslands, nesting in stick nests built by crows, magpies or hawks. Highly nocturnal; they hunt over meadows, pastures and other open habitats for meadow voles.

Sometimes gregarious in winter, roosting in small groups in dense trees or shrubs. Males give a low, hollow “oooo” call; females give a variety of nasal barking and wailing calls. Territorial birds will often smack their wings together in flight to produce a loud single clap.

Cornell Lab: Long-eared Owl

Short-eared Owl (Asio flammeus)
Short-eared Owl

Total Length: 34-42 cm
Wingspan: 95-110 cm

Rather slender owl with yellow eyes framed by dark feather mask, very small “ear” tufts (often not visible), body buff-coloured, streaked with brown.

Found in open habitats including marshes, bogs, tundra and grassland. Nest on the ground in dense grasses or other low vegetation. They are active by day-primarily in the morning and evening-hunting for meadow voles and other small rodents by coursing over open habitats.

Call is a raspy, high barking sound; males give a series of low hoots.

Territorial birds can produce a rapid series of clapping sounds with their wings.

Cornell Lab: Short-eared Owl

Burrowing Owl (Athene cunicularia)
Burrowing Owl

Total Length: 19-25 cm
Wingspan: 92 cm

A long-legged, ground-dwelling owl with yellow eyes, spotted brown plumage, no “ear” tufts. Young have a less spotted brown plumage. Found in a variety of open habitats: savannas, desert and grasslands. Nests are placed underground, usually in abandoned animal burrows, sometimes in loose colonies. Migratory, flying to California and Mexico in October and returning in late March.

Diet includes insects, rodents, songbirds, and reptiles.

Burrowing Owls are listed as Endangered in Canada and were extirpated from British Columbia in the 1970s. There is an active effort to reintroduce this species into BC using captive breeding and release programs.

Male courtship call is a mellow “coo-coo oo”; another common call is a nasal “kee kikadik”. When the young are alarmed they produce a vibrating hiss much surprisingly similar to the sound of a rattlesnake.

Cornell Lab: Burrowing Owl

Barn Owl(Tyto alba)
Barn Owl

Total Length: 29-44 cm
Wingspan: 107 cm

Generally pale owl with dark brown eyes, heart shaped face, no “ear” tufts, deep rust or buffy colour. Males are paler than females.

Found in a wide variety of habitats that include open areas. They hunt at night for meadow voles over pastures and grasslands, and nest in abandoned buildings, caves, barns, and tree cavities. Barn Owls will breed year-round if food is plentiful. They are non-migratory and cannot survive long in areas with deep winter snow.

Call is a long hissing scream, with screeching, twittering, and squeaking sounds. They do not hoot.

Cornell Lab: Barn Owl

Northern Hawk Owl (Surnia ulula)
Northern Hawk Owl

Total Length: 36-41cm
Wingspan: 84 cm

Characteristics are long wings and tail (like hawk or falcon), round face framed with black, and a barred chest. Habitat includes old burns in subalpine or boreal forests, and northern mixed woodlands. Nest in tree cavities. Perch in the open on treetops, scanning for prey. Flight is low and swift-falcon-like–and they sometimes hover over prey. They feed primarily on meadow voles, and are somewhat nomadic in their search for areas with high densities of this prey.

Male courtship call is a trilling, melodious whistle; other calls include chirping and screeching.

Cornell Lab: Northern Hawk Owl

Large Owls

Great Grey Owl (Strix nebulosa)
Great Grey Owl

Total Length: 57-70 cm
Wingspan: 132 cm

Very large, grey owl with yellow eyes set in a very large facial disc, no “ear” tufts, white “bowtie”.

Found in montane and boreal forests, wooded bogs, and mixed or coniferous forests with meadow clearings. Nests in abandoned crow or hawk nests; also commonly on top of large, broken-top snags. Generally non-migratory; hunts both day and night for small rodents, primarily meadow voles and pocket-gophers.

Call is a series of deep resonant WHOOs.

Provincial Bird of Manitoba.

Cornell Lab: Great Grey Owl

Great Horned Owl (Bubo virginianus)
Great Horned Owl

Total Length: 45-64 cm
Wingspan: 114 cm

Large owl with distinct “horns”, deep yellow eyes, white bib under chin, body mottled grey and brown. This is the most widespread owl in Canada, found in almost every habitat except tundra. They nest in stick nests built by hawks, crows, ravens or other large birds, also cliff ledges. Great Horned Owls hunt medium-sized prey such as rats, rabbits, hares, skunks, grouse, but will also take mice and a wide variety of other prey. Call is a rhythmic ‘Hoo-Hoohoo-Hoo-Hoo’; young birds give loud, rising screeches.

Provincial Bird of Alberta.

Cornell Lab: Great Horned Owl

Snowy Owl (Bubo scandiacus)
Snowy Owl

Total Length: 53-70 cm
Wingspan: 132 cm

Very large (the heaviest owl in North America) white owl with deep yellow eyes, black beak, smooth head, no “ear” tufts. Females and immature birds have more grey flecking than adult males, which can be pure white.

Breed on arctic tundra, in winter found primarily along coastlines or open grasslands, grain farms. Diet on the breeding grounds consists of lemmings, ptarmigan and other available prey; in the winter they eat a wide variety of prey, but primarily ducks, grebes, and larger rodents. Generally remain at high latitudes throughout the year, but some (primarily young birds) move south in winter when prey availability is low in the Arctic.

Snowy Owls are silent in winter; on the breeding grounds they give for deep hoots and harsh barking calls.

The Provincial Bird of Quebec.

Cornell Lab: Snowy Owl

Spotted Owl (Strix occidentalis)
Spotted Owl

Total Length: 41-48 cm
Wingspan: 109 cm

Large owl with round, large head, no “ear” tufts, dark brown eyes, yellow bill. Chocolate brown above, breast and belly heavily spotted and barred with brown.

Found in old growth coniferous forests; nests atop large broken-top trees and on mistletoe platforms. Nocturnal and non-migratory, their diet in British Columbia consists mainly of woodrats and flying squirrels; also large insects.

Call is a series of 3 or 4 barks and hoots: Hoo! Hoo-hoo! Hoooo! Female gives a loud rising whistle as a contact call.

Threatened by habitat loss through logging; the Spotted Owl is listed as Endangered in Canada and only a handful of adults remain in the wild. A captive breeding program is underway to save this species in British Columbia.

Cornell Lab: Spotted Owl

Barred Owl (Strix occidentalis)
Barred Owl

Total Length: 48-55 cm
Wingspan: 107-111 cm

Large grey-brown owl with round head, dark eyes, yellow bill; belly white with strong brown vertical streaks.

Call a deep, soft ‘boop” or ‘boo-boop” repeated at intervals of 2-3 seconds.

Found in dense coniferous forests, nesting in large tree cavities, mistletoe platforms, and old hawk nests. They hunt a wide variety of prey, from mice to squirrels and grouse.

Calls are rhythmic hoots in series of eight notes that sound like “who cooks for you—who cooks for you-allll”. Also a drawn out “hoo-ah”, various barking calls and shrieking whistles.

Cornell Lab: Barred Owl