Species

• Tytoninae (barn and bay owls)
• Striginae (all other owls)

Subspecies

There are 160 subspecies of owls in the world. I will attempt to list as many of these as I can, along with some information. If there is a spieces that you know of and is not listed, please email me and I will add it to the list.

Basic Facts

• Owls are basically nocturnal or crepuscular (active in the late morning or early evening). However, during winter, some species may be observed almost any time and in a variety of habitats because they are in search of food. Because most owls are active in times of low light or complete darkness, they have evolved a low- frequency vocal repertoire as a means of communication. Familiarity with these primary songs can greatly facilitate owl identifications.

• Owls have two primary hunting methods: (1) "perch and pounce," which usually takes place from a low perch and is most common among forest owls, and (2) "quartering," which means flying low over the ground; it is most common among open-country owls.

• Owls have evolved several important adaptations to help them cope with their lifestyles. Some of the most recognizable characteristics include: Large heads to accommodate large eyes and ears. Owls cannot move their eyes up, down, or side to side like humans can, so owls have evolved the ability to rotate their heads approximately 270 degrees. The ears in some species are asymmmetrical (the right ear is longer and situated higher on the skull), allowing them to calculate flight angles when sounds are heard but prey cannot be seen. Owl feathers in many species are structured so that sound created by flight is absorbed; consequently, these owls can hear but not be heard by potential prey when flying. Owls usually vocalize at low frequency. These sound waves carry long distances and are not absorded by barriers such as vegetation as quickly as high-frequency vocalizations.

Eastern Screech Owl

The origin of the word "Asio" is unknown, but it came to mean "Owl" in Latin. Eastern Screech Owls have also been called the common screech Owl, Ghost Owl, Dusk Owl, Little-eared Owl, Spirit Owl, Little Dukelet, Texas Screech-Owl, whickering Owl, little grey Owl, mottled Owl, the red Owl, the mouse Owl, the cat Owl, the shivering Owl, and the little horned Owl.

Description: The Eastern Screech Owl is a small, nocturnal, woodland Owl. There are two colour morphs, a grey phase and a reddish-brown phase. Adult (grey phase) - facial disks dusky white with fine grey-brown mottling, bordered by black. The iris is bright yellow and the bill is grey-green, with tufts of bristly feathers around its base. Overall grey-brown, with grey narrow vertical stripes, bars, and spots on underparts, and barred wings and tail - legs light cinnamon buff, and toes are yellow.

Adult (red phase) - similar pattern to grey phase except cinnamon instead of grey - face plain light cinnamon - whitish superciliary and loral plumage. Juvenile (grey phase) - similar to adults but indistinct stripes and bars more patterned - many feathers tipped with white Juvenile (red phase) - greyish brown, but distinctly rufescent colour overall - bars and stripes less distinct than adults.

Eastern Screech-Owls can be confused with Western Screech-Owls. These Owls can be distinguished by their different calls, and only occur together locally in eastern Colorado and southern Texas.

The Eastern Screech-Owl flies fairly rapidly with a steady wingbeat (about 5 strokes/second). They rarely glide or hover, but may fly with erratic movements, when manoeuvring through wooded areas. Their wings are broad and the head is held tucked in giving the bird a stubby appearance when flying.

When threatened, an Eastern Screech Owl will stretch its body and tighten its feathers in order to look like a branch stub to avoid detection, but will take flight when it knows it has been detected. In open roosts, grey-phase birds tend to roost next to a tree trunk, whereas red-phase birds tend to roost in outer foliage, possibly because of thermal requirements.

Size: Female average Length:23cm (9.2") Wingspan:56cm (22") Weight:208g (7.3oz)

Male average Length:21cm (8.2") Wingspan:54 cm (21") Weight:200 g (7oz)

Voice: Males have a lower-pitched voice than females. The male's most common call is an eerie, mellow, muted trill given during the mating and nesting seasons. Each call lasts 2 to 3 seconds with about 35 notes given, and repeated at various intervals. This call is primarily territorial in nature and announces ownership of nest cavities. When in the nest with young, adults give a descending whinny call, instead of the normal call. This whinny call is given through the winter until the mating call begins again. Females tend to bark or hoot when defending the nest. Young "peep" for food during their first three weeks, then chatter or hum later. Fledglings demand food with a harsh "keeeerr-r-r-r". They do not call while in flight, except when alarmed.

Hunting: Eastern Screech Owls hunt from dusk to dawn, with most hunting being done during the first four hours of darkness. They mainly search for prey while in flight, rather from a perch. They hunt mainly in open woodlands, along the edges of open fields or wetlands, or makes short forays into open fields. When prey are spotted, the Owl dives quickly and seizes it in its talons. They will also capture flying insects on the wing. Small prey will usually be swallowed whole on the spot, while larger prey is carried in the bill to a perch and then torn into pieces. An Eastern Screech Owl will tend to frequent areas in its home range where it hunted successfully on previous nights. They are opportunistic hunters and will switch to almost any suitably-sized prey when abundant. An extremely wide range of prey species is captured, the most favoured being small microtine rodents and deer mice. Other mammals taken include wood and Norway rats, chipmunks, cotton rats, squirrels, shrews, bats, and moles. Large flying insects are also taken, such as beetles, katydids, grasshoppers, locusts, crickets, mantids, roaches, cicadas, moths, horseflies, and dragonflies. Birds, including many species of small songbirds, and larger birds such as Northern Bobwhite, Rock Dove, Ruffed Grouse, and other screech-Owls comprise about 7% of an Eastern Screech Owl's diet. They may be captured more often during periods of heavy songbird migration. Other prey include small fish, small snakes, lizards, and soft-shelled turtles, small frogs, toads, and salamanders, and invertebrates such as crayfish, snails, spiders, earthworms, scorpions, and centipedes. They have been observed fishing at holes in lake ice left by fishers, or at open pockets of water. Pellets are medium-sized, averaging about 3.8 by 1.9 cm (1.5 by 0.75" inches). They are compact, dark grey, ovals that are composed of fur, feathers, bones, teeth, and chitin. Two to four pellets are expelled per day.

Breeding: Eastern Screech Owls have an elaborate courtship ritual. Males approach females, calling from different branches until they are close. The male then bobs and swivels his head, bobs his entire body, and even slowly winks one eye at the female. If she ignores him, bobbing and swivelling motions intensify. If she accepts him, she moves close and they touch bills and preen each other. Pairs mate for life but will accept a new mate if the previous mate disappears. Grey and red colour phases will mate together.

They nest almost exclusively in tree cavities, with enlarged natural cavities being preferred, but they will also use old Pileated Woodpecker and Northern Flicker cavities. Nest cavities are usually 2 to 6 meters (6.5 to 20 feet) above the ground, but may be up to 15 meters (50 feet. They will readily nest in suitable nest boxes and occasionally behind loose boards on abandoned buildings or barns. Nests are almost always in deciduous trees such as oaks, elms, maples, sycamores, willows, and apples; occasionally in pines. Pairs will often reuse nest sites in consecutive years. No nest material is added, and the 2 to 8 (average 3-5) eggs are laid on natural sawdust on floor of cavity. Eggs are laid every two days and incubation begins after laying of the first egg. The incubation period is about 26 days and the fledging period about 31 days. Females do most of the incubating but males will assist. The male provides most of the food while the female broods the young, and will stockpile food during early stages. Eastern Screech Owls are single brooded, but may re-nest if the first clutch is lost. When the young are small the female tears the food up for them.

Adults tend to remain near their breeding areas year-round while juveniles disperse in the autumn. Siblings tend to disperse together. Small territories around nest sites are vigorously defended by males, but pairs may nest within 50 meters (164 feet) of another pair. Breeding territories range from 4 to 6 hectares (10 to 15 acres) in wooded suburban areas to 30 hectares (75 acres) in more open rural areas. Home ranges are much larger, up to 80 hectares (200 acres), but these are not defended and there is much overlap between pairs.

Mortality: While captive Eastern Screech Owls have lived for over 20 years, wild birds would be unlikely to reach this age. Juvenile and adult mortality may be as high as 70% and 30% respectively. Predators of these Owls include Great Horned Owls, Barred Owls, Long-eared Owls, Great grey Owls, Short-eared Owls, Snowy Owls, mink, weasels, raccoons, skunks, snakes, crows, and Blue Jays. Cannibalism by other screech-Owls also occurs. Eastern Screech Owls are the second most frequently killed bird by moving vehicles, after American Robins.

Habitat: Eastern Screech Owls inhabit open mixed woodlands, deciduous forests, parklands, wooded suburban areas, riparian woods along streams and wetlands (especially in drier areas), mature orchards, and woodlands near marshes, meadows, and fields. They will avoid dense forests because Great Horned Owls use that habitat. They will also avoid high elevation forests. Eastern Screech Owls roost mainly in natural cavities in large trees, including cavities open to the sky during dry weather. In suburban and rural areas they may roost behind loose boards on buildings, boxcars, or water tanks. They will also roost in dense foliage of trees, usually on a branch next to the trunk, or in dense scrubby brush.

Western Screech Owl

Originally, this bird was officially called "Kennicott's Owl". Common names include Little Horned Owl, Dusk Owl, Ghost Owl, Mouse Owl, Cat Owl, Little Cat Owl, Puget Sound Screech Owl, Washington Screech Owl, and Coastal Screech Owl. Description: The Western Screech Owl is a small, nocturnal, woodland Owl of western North America and is one of the west's more common Owls at lower elevations. They are squat-looking Owls that sit erect, with their plumage fluffed out, with the feet and legs obscured, and distinct ear tufts raised. The iris is bright yellow and the bill is black, with tufts of bristly feathers around its base. The facial disk is bordered by black. The toes are yellow. plumage is either mainly greyish or reddish-brown variegated dark and light, that resembles a furrowed tree bark pattern, and is virtually identical to the Eastern Screech Owl. (They use the variegated plumage as camouflage. When threatened, the bird stretches its body and tightens its feathers in order to look like a branch stub to avoid detection, but will take flight when it knows it has been detected). They have noticeable light spotting along the edge of the scapulars. There is much individual variation within the two colour morphs. In the grey-phase, birds in the dry southwest are a paler grey, while birds in the humid northwest are darker and browner. The red-phase is very rare and found only in the Pacific Northwest. Adult (grey phase) - Facial disks are dusky white with fine grey-brown mottling. Overall grey-brown, with grey-brown narrow vertical stripes, bars, and spots on the underparts, and barred wings and tail. The legs have fine buff mottling. Adult (red phase) - Similar pattern to grey phase except dull cinnamon instead of grey. The face is buff light cinnamon. There is rufous spotting on the breast with black anchor marks. The juvenile of both colour phases is similar to the adults, but the indistinct stripes and bars are more patterned, with many feathers tipped with white. The Western Screech Owl is likely to be confused with the Eastern Screech Owl and Whiskered Screech Owl. These Owls can be distinguished by their different calls. Western and Eastern Screech Owls only occur together locally in eastern Colorado and southern Texas. Western and Whiskered Screech Owls only occur together in southern Arizona and Mexico. During direct flight, the Western Screech Owl flies fairly rapidly with a steady wing beat of about 5 strokes/second. It rarely glides or hovers, but may fly bat-like with erratic movements, when manoeuvring through wooded areas. Wings are broad and the head is held tucked in giving a flying bird a stubby appearance. Size: Female average Length: 23cm (9.2") Wingspan 56cm (22") Male average Length: 21cm (8.2") Wingspan 54cm (21") Weights of different subspecies vary widely. In general, weights decrease from north to south, from an average of 186g (6.5oz) for females and 152g (5.3oz) for males in a northern population to 123g (4.3oz) for females and 111g (3.9oz) for males in a southern population. Voice: The male's most common call is a mellow, muted trill "hoo-hoo-hoo....", or bouncing ball song, that speeds up at the end, but maintains a constant pitch. It is given by the male during the mating and nesting seasons, but also during the autumn and winter. This call is primarily territorial in nature. A secondary song is a double trill of rapid bursts. Other calls are a soft "cr-r-oo-oo-oo-oo" given as a greeting call, and a sharp bark given when excited. Hunting: Western Screech Owls are nocturnal, hunting from dusk to dawn, before retiring to daytime roosts. They hunt mainly in open woodlands, along the edges of open fields or wetlands, or makes short forays into open fields, searching for prey mainly while in flight, rather than from a perch. When prey is located, the Owl dives quickly and seizes it in its talons. they also capture flying insects on the wing. Small prey is usually swallowed whole on the spot, while larger prey is carried in the bill to a perch and then torn apart. An extremely wide range of prey species is captured. The most favoured prey are small microtine rodents and deer mice, larger insects, or small birds depending on abundance. Prey species include shrews, orthopterons, insects (including beetles, larval moths & butterflies), birds, pocket gophers, voles, salamanders, kangaroo rats, wood rats, pocket mice, grasshopper mice, gophers, frogs, locusts, and scorpions, crayfish, worms, snails, small fish, poultry, and barnyard ducks. Pellets are medium-sized, averaging about 3.8 by 1.9 centimetres (1.5 by 0.75 inches). They are compact, dark grey, ovals composed of fur, feathers, bones, teeth, and chitin. Two to four pellets are cast each day. Breeding: During courtship males and females call to e ach other in a duet as they approach each other. When together they preen each other's heads and nibble at the other's beaks. The male then changes his call to a rapid tremolo, answered with a short, tremolo from the female. Western Screech Owls nest almost exclusively in tree cavities. Enlarged natural cavities are preferred but they will also use old Pileated Woodpecker and rotted-out Northern Flicker holes. Nest cavities are usually 2 to 6 metres (6.5 to 20 feet) above the ground, but may be up to 15 metres (50 feet) up. They will readily nest in suitable nest boxes. Nests are almost always in deciduous trees such as oaks, cottonwoods, maples, sycamores and large willows, but also in large cacti, Douglas-fir snags, and junipers. One subspecies in Arizona nests exclusively in saguaro cacti. No nest material is added and nests are kept cleaner than in Eastern Screech Owls. 2 to 5 (average 3-4) eggs are laid on natural sawdust on the floor of the cavity. The average clutch size tends to increase from south to north and from the coast inland. The eggs are laid every 1 to 2 days and incubation begins after laying of the first. The incubation period is about 26 days and the fledging period about 35 days. Females incubate eggs and brood young while males bring food to the nest. The Western Screech Owl is single brooded, but may re-nest if first clutch is lost. Pairs will often reuse nest sites in consecutive years. Pairs mate for life but will accept a new mate if the previous mate is lost. Grey and red colour phases will mate together. Adults tend to remain near their breeding areas year-round while juveniles disperse in the autumn. Small territories around nest sites are vigorously defended by males. In desert riparian areas of the southwest, where these Owls can be quite numerous, territories may be only 50 meters (165 feet) apart. Home ranges are much larger, and range from 3 to 60 hectares (7.5 to 150 acres), but these are not defended and there is much overlap between pairs. Mortality: Western Screech Owls can fall prey to Northern Goshawks, Cooper's Hawks, Great Horned Owls, Barred Owls, Spotted Owls, Long-eared Owls, Great grey Owls, Short-eared Owls, mink, weasels, raccoons, skunks, squirrels, snakes, and crows. Cannibalism by other Screech Owls also occurs. Western Screech Owls are dependent on deciduous woodlands or open mixed forests that have suitable nesting sites and sufficient prey densities. Removal of riparian forest in drier regions will cause population declines because most densities are highest in riparian zones. However, this adaptable Owl can survive in wooded suburban areas and city parks as long as long as they are not directly persecuted. Populations likely fluctuate more depending on prey availability. Nest box programs can enhance local populations, especially in areas short of suitable tree cavities. Silviculture practices that include removal of dead and dying trees can eliminate this bird as a breeding species from local areas. Habitat: Western Screech Owls inhabit a wide variety of habitats. On the northwest coast, they inhabits humid Douglas-fir, western hemlock, western red cedar, and Sitka spruce forests along the edges of clearings, rivers, and lakes. Further inland they occupy a narrow ecological niche of lowland deciduous forests, especially riparian woodlands along river bottoms. Southern populations inhabit lowland riparian forests, oak-filled arroyos, desert saguaro and cardon cacti stands, Joshua tree and mesquite groves, and open pine and pinyon-juniper forests. They avoid dense forests because Great Horned Owls use that habitat, and high elevation forests. In general, they require open forests, with an abundance of small mammals and insect prey, and cavities for nesting. They roost mainly in natural or woodpecker cavities in large trees, but also in dense foliage of deciduous trees, usually on a branch next to the trunk, or in dense conifers.

Snowy Owl

The name "scandiaca" is a Latinised word referring to Scandinavia, as the Owl was first observed in the northern parts of Europe. Some other names for the Snowy Owl are Arctic Owl, Great White Owl, Ghost Owl, Ermine Owl, Tundra Ghost, Ookpik, Scandinavian Nightbird, White Terror of the North, and Highland Tundra Owl. It is the official bird of Quebec. Description: The Snowy Owl is a large, diurnal white Owl that has a rounded head, yellow eyes and black bill. The feet are heavily feathered. A distinctive white Owl, their overall plumage is variably barred or speckled with thin, black, horizontal bars or spots. Females and juveniles are more heavily marked than males - adult males may be almost pure white, although they have up to three tail bands. Adult females are distinctly barred throughout, and have from four to six tail bands. Immatures are very heavily barred throughout, and dark spotting may codominate or dominate the overall plumage. Intensity of dark spotting varies with the sex of the immatures, females being the darkest. Juveniles are uniformly brown with scattered white tips of down. Snowy Owls have a direct, strong, and steady flight with deliberate, powerful downstrokes and quick upstrokes. They make short flights, close to the ground, from perch to perch, and usually perches on the ground or a low post. During hot weather, they can thermoregulate by panting and spreading their wings. Size: Length 51-68� cm (20-27") average female 66cm (26" inches), male 59cm (23") Wingspan 137-164cm (54-65") Weight 1134-2000g (40-70oz) average female 1707g (60oz), male 1612g (57oz) Voice: The Snowy Owl is virtually silent during nonbreeding seasons. During the breeding season males have a loud, booming "hoo, hoo" given as a territorial advertisement or mating call. Females rarely hoot. Its attack call is a guttural "krufff-guh-guh-guk". When excited it may emit a loud "hooo-uh, hooo-uh, hooo-uh, wuh-wuh-wuh". Other sounds are dog-like barks, rattling cackles, shrieks, hissing, and bill-snapping. Nestlings "cheep" up to 2 weeks of age, then hiss and squeal. Hunting: Most hunting is done in the "sit and wait" style, swivelling the head as much as 270 degrees scanning for prey. These Owls are highly diurnal, although it may hunt at night as well. Prey are captured on the ground, in the air, or snatched off the surface of water bodies. When taking snowshoe hares, a Snowy Owl will sink its talons into the back and backflap until the hare is exhausted. The Owl will then breaks its neck with its beak. Snowy Owls will often raid traplines for trapped animals and bait, and will learn to follow traplines regularly. They also snatch fish with their talons. Small prey up to small hares are swallowed whole, while larger prey are carried away and torn into large chunks. Small young are fed boneless and furless pieces. Large prey are carried of in the Owl's talons, with prey like lemmings being carried in the beak. Snowy Owls are mainly dependent on lemmings and voles throughout most of their Arctic and wintering range. When these prey are scarce they are an opportunistic feeder and will take a wide range of small mammals and birds. Some mammal prey include mice, hares, muskrats, marmots, squirrels, rabbits, prairie dogs, rats, moles, and entrapped furbearers. Birds include ptarmigan, ducks, geese, shorebirds, Ring-necked Pheasants, grouse, American coots, grebes, gulls, songbirds, and Short-eared Owls. Snowy Owls will also take fish and carrion. Some nesting Owls switch from lemmings and voles to young ptarmigan when they become available. Snowy Owls do not hunt near their nests, so other birds, such as Snow Geese, often nest nearby to take advantage of the Owls driving off predators such as foxes. Snowy Owls produce large, rough-looking cylindrical pellets with numerous bones, feathers, and fur showing. They are usually expelled at traditional roosting sites and large numbers of pellets can be found in one spot. When large prey are eaten in small pieces with little roughage, pellets will not be produced. Breeding: Courtship behaviour can begin in midwinter through to March and April, well away from breeding areas. Males will fly in undulating, moth-like flight when females are visible. On the ground males will bow, fluff feathers, and strut around with wings spread and dragging on the ground. Males kill and display prey in caches to impress females, often feeding the female. The Snowy Owl nests almost exclusively on the ground, where the female makes a shallow scrape with her talons on top of an elevated rise, mound, or boulder. Abandoned eagle nests and gravel bars are used occasionally. Nests may be lined with scraps of vegetation and Owl feathers. Nest sites must be near good hunting areas, be snow-free, and command a view of surroundings. There is little breeding site-faithfulness between years or mates in some areas, but in other areas, a pair of Owls may nest in the same spot for several years. Territories around nests range from 1� to 6� square kilometres (0.6 to 2� square miles), and overlap with other pairs. Breeding occurs in May, Clutch and brood sizes are heavily dependent on food supply. Snowy Owls may not nest at all during years of low lemming numbers. Clutch sizes normally range from 5 to 8 white eggs but may be as many as 14 eggs during high lemming years. They are laid at approximately 2 day intervals. The female incubates while the male brings her food and guards the nest. Eggs hatch in 32-34 days at two day intervals, leading to large age differences in nests with large clutch sizes. Young are covered in white down. Young begin to leave the nest after about 25 days, well before they can fly. They are fledged at 50 to 60 days. Both parents feed and tend the young, and are fiercely protective and may attack intruders up to 1 kilometre (0.6 miles) from the nest! Nestling Owls require about 2 lemmings/day and a family of Snowy Owls may eat as many as 1,500 lemmings before the young disperse. Snowy Owls are single brooded and likely do not lay replacement clutches if their first clutch is lost. Almost 100% nesting success can be achieved during good vole years. Numbers fluctuate wildly, usually in concert with lemming and vole numbers. For Example, Banks Island may have 15,000 to 20,000 Snowy Owls during good lemming years and only 2,000 during low lemming years with densities ranging from 1 Owl per 2.6 square kilometre (1 Owl per square mile) in good lemming years to 1 Owl per 26 square kilometres (1 Owl per 10 square miles) in low lemming years. Mortality: Snowy Owls can live at least 9� years in the wild and 35 years in captivity. Natural enemies are few - Arctic foxes and wolves prey apon them on thier tundra breeding grounds, while skuas and jaegers may take eggs or chicks. Habitat: The Snowy Owl is a bird of Arctic tundra or open grasslands and fields. They rarely venture into forested areas. During southward movements they appear along lakeshores, marine coastlines, marshes, and even roost on buildings in cities and towns. In the Arctic, they normally roost on pingaluks (rises in the tundra) and breed from low valley floors up to mountain slopes and plateaus over 1,000 meters (3,000 feet) in elevation. When wintering in the Arctic, they frequent wind-swept tundra with little snow or ice accumulation. At more southern latitudes they typically frequents agricultural areas.

Northern Saw-whet Owl

The Latinised word "acadius" refers to this territory. The common name "Saw-whet" comes from these Owls unique calls described below. The Saw-whet Owl is also called Acadian Owl, blind Owl, Kirkland's Owl, the saw-filer, the sawyer, sparrow Owl, white-fronted Owl, Farmland Owl, Little Nightbird, Queen Charlotte Owl, and even the Whet-saw Owl. Description: The Northern Saw-whet Owl is a very small, short-bodied, nocturnal Owl with an overly large head. The head is "earless" and may appear distorted due to an asymmetrical skull. They look small when perched and tend to shuffle their feet. but in flight appear larger because of their broad wings. Plumage is quite fluffy and brownish or reddish brown overall streaked with white underneath and spotted on the back. The crown is finely streaked with white. The facial disk is greyish, and the eyes are large and bright yellow. The bill is black. The legs and feet are light buff and heavily feathered. They tend to depend on plumage for camouflage when roosting in foliage, but when threatened, a Saw-whet Owl will elongate its body in order to appear like a tree branch or bump. Size: Length average 20cm (7�") Wingspan average 52cm (20") Weight 75-110g (2.6-3.9oz) - Females are slightly larger than males. Voice: The Northern Saw-whet Owl vocalises during the breeding season only (usually b etween March and May). They are silent at other times of the year. The primary courtship call is a monotonous, whistled "hoop", emitted at about 1� notes per second which may last for several hours without a break. Territorial calls are series of short clear notes. The Saw-whet Owl's name comes from the "skiew" call that is made when alarmed. This sound has a resemblance to the whetting of a saw. When the male flies to the nest with food it gives a rapid staccato burst of toots, and the female responds with a soft "swEE". Hunting: These Owls hunt mainly at dusk and dawn and most often use the "sit and wait" tactic to drop down onto prey on the ground from low hunting perches.They will also range through wooded areas and hunt in heavy shrub cover. When prey is plentiful, a Saw-whet Owl will kill as many as 6 mice in rapid succession, without consuming any of them. The excess food is cached in safe places and, in winter, is thawed out later by "brooding" the frozen carcass. When food is plentiful, it is common for only the head of each prey to be eaten. Northern Saw-whet Owls feed almost entirely on small mammals, Deer mice being the primary prey, followed by shrews and voles. Other mammals include squirrels, moles, bats, flying squirrels, and house mice. Small birds are sometimes taken and include swallows, sparrows, chickadees, and kinglets. Larger birds such as Northern Cardinal and Rock Dove can be killed by one of these small Owls. Frogs and insects are also part of their diet. Pellets are very small, about 1.9cm (�") by 1.3cm (�") and are ejected with great difficulty, usually with a great deal of twisting of the body and head. Breeding: Because of their nomadic nature it is unlikely that pair bonds are permanent or that birds often return to the same nest site. Males sing their territorial song mainly in April. After a female has been attracted to a male by his song, he will fly in circles above her while calling. The male then lands near her and begins a complex series of bobbing and shuffling as he inches towards her. Often, the male has a mouse in its bill and offers it to the female. Northern Saw-whet Owls nest in old woodpecker cavities, (primarily those made by Northern Flickers or Hairy Woodpeckers) or in natural cavities. They will also take to nest boxes quite readily. Nest trees are often dead and nest heights average 4 to 6 metres (13-20 feet) above ground. Nesting occurs between March and July. Clutch sizes range from 4 to 7 eggs (average 5-6) laid at periods of 1 to 3 days, but usually 2. The female does all incubation and the male brings food to her and defends the nesting area. The incubation period is 26 to 28 days. Young fledge at 4 to 5 weeks, and may leave the nest individually every 1 to 2 days, until they have all left. A pair will usually raise a single brood, but during years when food is abundant, they may be double or even triple brooded. Mortality: Captive Owls have lived for 8 years, but mortality in the wild is likely relatively high. They compete with Boreal Owls, starlings, and squirrels for nest cavities, and are preyed upon by larger Owls, martens, Cooper's Hawks, and Northern Goshawks. Habitat: Northern Saw-whet Owls inhabit coniferous and deciduous forests, with thickets of second-growth or shrubs. They occur mainly in forests with deciduous trees, where woodpeckers create cavities for nest sites. Breeding habitat is usually swampy or wet, rather than dry. Riparian habitat is often preferred.

Barred Owl

In Latin, "varia" is a form of the word "varius", meaning diverse. It has also been known as Northern Barred Owl, Swamp Owl, Striped Owl, Hoot Owl, Eight hooter, Round-headed Owl, Le Chat-huant du Nord (French for "The Hooting Cat of the North"), Wood Owl, and Rain Owl. Description: The Barred Owl is a medium-sized grey-brown Owl streaked with white horizontal barring on the chest and vertical barring on the belly. They are round-headed with a whitish/brown facial disk with dark brown trim. The eyes are brown, and the beak is yellow and almost covered by feathers. They have a long tail. There is no difference in plumage between males and the larger females. Size: Length 40-63 cm (16-25 inches) Wingspan 96-125 cm (38-50 inches) Weight: 500-1050 grams (17�-37 oz) (average male 617g, average female 779g) Voice: The Barred Owl is a highly vocal Owl giving a loud and resounding "hoo, hoo, too-HOO; hoo, hoo, too-HOO, ooo" which is often phrased as "Who, cooks, for-you? Who, cooks, for-you, all?" - The last syllable drops off noticeably. Like some other Owl species, they will call in the daytime as well as at night. The calls are often heard in a series of eight, then silence, when the Owl listens for a reply from other Owls. Other calls include "hoo-hoo, hoo-WAAAHH" and "hoo-WAAAHHH" used in courtship. Mates will duet, but the male's voice is deeper and mellower. Many other vocalisations are made which range from a short yelp or bark to a frenzied and raucous monkey-like squall. Hunting: A very opportunistic hunter, the Barred Owl can sometimes be seen hunting before dark. This typically occurs during the nesting season or on dark and cloudy days. The Barred Owl uses a perch, from where it dives upon its prey - meadow voles are its main prey, followed by shrews and deer mice. Other mammals include rats, squirrels, young rabbits, bats, moles, opossums, mink, and weasels. Birds are taken occasionally, including woodpeckers, grouse, quail, jays, blackbirds, and pigeons. They also eats small fish, turtles, frogs, snakes, lizards, crayfish, scorpions, beetles, crickets, and grasshoppers. Birds are taken as they settle into nocturnal roosts, because the Barred Owl cannot catch birds on the wing. They will also swoop down to the water's edge to catch frogs, other amphibians, and occasionally fish. The Barred Owls are attracted to campfires and lights where they forage for large insects. Prey is usually devoured on the spot. Larger prey is carried to a feeding perch and torn apart before eating. Breeding: The Barred Owl calls year-round but courtship activities begin in February with breeding occurring between March and August. Males hoot and females give contact calls. As the nesting season approaches, males chase after females giving a variety of hooting and screeching calls. Males display by swaying back and forth, and raising their wings, while sidling along a branch. Courtship feeding and mutual preening also occur. Barred Owls nest in cavities and will also use abandoned Red-shouldered Hawk, Cooper's Hawk, Squirrel, or Crow nests. Eggs number 2-4 and are white, and almost perfectly round, with a slightly rough texture. They are likely laid every 2 to 3 days and incubation begins with the first egg laid. Incubation period is 28-33 days. The Male brings food to the female while she is on the nest. The Barred Owl is single-brooded but has a long breeding season, which allows for laying of replacement clutches if the first clutch or brood is lost.When the young leave the nest, at about 4 weeks, they are not able to fly, but crawl out of the nest using their beak and talons to sit on branches. These Owls are called branchers. They fledge at 35 to 40 days. Once they lose their down, there is no difference between adult and juvenile plumage. Parents care for the young for at least 4 months, much longer than most other Owls.Young tend to disperse very short distances, usually less than 10 kilometres (6 miles), before settling. Pairs mate for life and territories and nest sites are maintained for many years. Mortality: Barred Owls have been known to live up to 23 years in captivity and 10 years in the wild. Most deaths are likely to be related to man (shootings, roadkills etc). Great Horned Owls are their only natural enemy. Habitat: The Barred Owl prefers deep moist forests, wooded swamps, and woodlands near waterways. Territories are 85-365 hectares (213-903 acres).

Burrowing Owl

The Latin word "cunicularius" means mine, or miner - an apt description for a bird that makes its home beneath the ground. The Burrowing Owl has also been known as Ground Owl, Prairie Dog Owl, Rattlesnake Owl, Howdy Owl, Cuckoo Owl, Tunnel Owl, Gopher Owl, and Hill Owl. Description: A small ground-dwelling Owl with a round head and no ear tufts. They have white eyebrows, yellow eyes, and long legs. The Owl is sandy coloured on the head, back, and upperparts of the wings and white-to-cream with barring on the breast and belly and a prominent white chin stripe. They have a rounded head, and yellow eyes with white eyebrows. The young are brown on the head, back, and wings with a white belly and chest. They moult into an adult-like plumage during their first summer. Burrowing Owls are comparatively easy to see because they are often active in daylight, and are suprisingly bold and approachable. The females are usually darker than the males. Burrowing Owls fly with irregular, jerky wingbeats and frequently make long glides, interspersed with rapid wingbeats. They hover during hunting and courtship, and may flap their wings asynchronously (not up and down together). Size: Length 21.6-28 cm (8�-11 inches) Wingspan 50.8-61.0 cm (20-24 inches) Weight 170.1-214g (6-7� oz) Voice: The main call is given only by adult males mainly when near the burrow to attract a female. A two-syllable "who-who" is given at the entrance of a promising burrow. This call is also associated with breeding, and territory defence. Other sounds called the "rasp", "chuck", "chatter", and "scream" have been described. Juveniles give a rattlesnake-like buzz when threatened in the burrow, and adults give a short, low-level "chuck" call to warn of approaching predators. This is usually accompanied by bobbing the head up and down. Hunting: Burrowing Owls feed on a wide variety of prey, changing food habits as location and time of year determine availability. Large arthropods, mainly beetles and grasshoppers, comprise a large portion of their diet. Small mammals, especially mice, rats, gophers, and ground squirrels, are also important food items. Other prey animals include: reptiles and amphibians, scorpions, young cottontail rabbits, bats, and birds, such as sparrows and horned larks. These Owls are quite versatile in the ways they capture prey. They chase down grasshoppers and beetles on the ground, use their talons to catch large insects in the air, or hover in mid-air before swooping down on unsuspecting prey. They also watch from perches, then glide silently toward their target. Burrowing Owls are primarily active at dusk and dawn (crepuscular), but will hunt throughout a 24-hour period, especially when they have young to feed. Unlike other Owls, they also eats fruits and seeds, especially the fruit of Tesajilla and prickly pear cactus. Breeding: The nesting season begins in late March or April. Burrowing Owls are usually monogamous but occasionally a male will have 2 mates. Courtship displays include flashing white markings, cooing, bowing, scratching and nipping. The male performs display flights, rising quickly to 30 meters (100 feet), hovering for 5 to 10 seconds, then dropping 15 meters (50 feet). This sequence is repeated many times. Circling flights also occur. Burrowing Owls nest underground in abandoned burrows dug by mammals or if soil conditions allow they will dig their own burrows. They will also use man made nest boxes placed underground. They often line their nest with an assortment of dry materials. Adults usually return to the same burrow or a nearby area each year. One or more "satellite" burrows can usually be found near the nest burrow, and are used by adult males during the nesting period and by juvenile Owls for a few weeks after they emerge from the nest. 6 to 9 (sometimes up to 12) white eggs are laid a day apart, which are incubated for 28-30 days by the female only. The male brings food to the female during incubation, and stands guard near the burrow by day. The care of the young while still in the nest is performed by the male. At 14 days, the young may be seen roosting at the entrance to the burrow, waiting for the adults to return with food. They leave the nest at about 44 days and begin chasing living insects when 49-56 days old. Mortality: Burrowing Owls are able to live for at least 9 years in the wild and over 10 years in captivity. They are often killed by vehicles when crossing roads, and have many natural enemies, including larger Owls, hawks, falcons, badgers, skunks, ferrets, armadillos, snakes, and domestic cats and dogs. They are listed as endangered, threatened, or a species of special concern in most states and provinces where they occur. Habitat: Burrowing Owls are found in open, dry grasslands, agricultural and range lands, and desert habitats often associated with burrowing animals, particularly prairie dogs, ground squirrels and badgers. They can also inhabit grass, forb, and shrub stages of pinyon and ponderosa pine habitats. They commonly perch on fence posts or on top of mounds outside the burrow. Burrowing Owls have been reported to nest in loose colonies. Such groupings may be a response to a local abundance of burrows and food, or an adaptation for mutual defence. Colony members can alert each other to the approach of predators and join in driving them off. During the nesting season, adult males forage over a home range of 2 to 3 square kilometres. Ranges of neighbouring males may overlap considerably. A small area around the nest burrow is aggressively defended against intrusions by other Burrowing Owls and predators.

Spotted Owl

The Latin word "occidentalis" refers to something from the west. Other names include Canyon Owl, Brown-eyed Owl, Wood Owl, and Hoot Owl. Description: The Spotted Owl is a nocturnal, woodland owl and is darkly coloured, with a round head , and dark brown eyes. Their brown plumage is heavily spotted with white on the breast and belly, with less spots on the wings, back, and head. The pale brown facial disks are concentrically ringed with dark brown. The eyebrows, lores, and bill are greyish. Its plumage is soft and fluffy, which can make the head appear oversized. The Spotted Owl is a placid owl, allowing close approach by humans and may be reluctant to fly. In flight, The Spotted Owl has heavy methodical wing beats, but appears buoyant for its size. When roosting, a Spotted Owl will sit on a branch, near the trunk, where it is camouflaged against tree bark and shadows. Size: Length: average 48cm (19") for females, 46cm (18") for males. Wingspan: average 109cm (43") for females, 106cm (42") for males. Weight: 518-760g (1-1� lbs) Voice: The typical advertisement call is a mellow, 4-note hoot, "hoo-hoohoo-hoo". Both Males and Females use it as a territorial call and mate-locating call. During territorial disputes, they give a more excited version of the call. Other calls are the "series location call", a series of 7 to 15 hoots, given during disputes and/or calls between paired birds. A "bark series" of 3 to 7 loud, rapid barks, usually given by the female during territorial squabbles, and then there is the "nest call" given during the prenesting period. Other sounds given when alarmed include grunts, groans, and chatters. The female often emits a loud "co-weeep" to contact her mate. Hunting: Hunting is done mainly at night, usually beginning just after sunset and ending a half hour before sunrise. Spotted Owls us a perch to "sit and wait" to dive down onto prey. They rarely forage in flight. Prey is sometimes cached for later use. Prey taken to the nest by the male is often decapitated first. During the day, a Spotted Owl may take the odd prey that passes by its dayroost, fly to a food cache, or fly to a nearby stream to drin k. Spotted Owls feed mainly on flying squirrels and wood rats. These prey are necessary for successful breeding. Other major prey include gophers, rabbits and hares. Summer diets are more varied with deer mice and voles being important foods. Spotted Owls are known to capture 30 mammal species including bats, and 23 bird species as prey. They also eat snakes, crickets, beetles, and moths. They have been known to walk around campgrounds at night to pick up scraps of food. Pellets are large and compact measuring about 5.1 to 7.6 centimetres (2 to 3 inches) in length. Pellets contain numerous bones, skulls, and teeth, and are held together by fur and mucus. Breeding: The breeding season is from March to September. Timing and success in producing offspring are strongly linked to the availability of prey, and not all pairs breed every year. Spotted owl pairs mate for life, but a new mate is readily taken if the other disappears. They probably begin breeding at two to three years of age. Spotted Owls nest primarily in stick nests of Northern Goshawks, on clumps of mistletoe, in large tree cavities, on broken tops of large trees, on large branches, or cavities in banks and rock faces. Old nests are not repaired before eggs are laid, and tend to be reused year after year. Clutch size ranges from 2 to 4 eggs, but averages 2 to 3 eggs. Eggs are laid every 3 to 4 days, usually in April. The female does all incubation and the male delivers food to the nest. The incubation period is about 28 to 32 days. Unlike most other owls, Spotted Owls may not defend their eggs and young from predators, watching nearby as the nest is destroyed. Young are brooded constantly by the female for 2 weeks, then she begins to hunt as well. The male brings food to the nest and passes it to the female to feed to the young. Young start roaming from the nest onto nearby branches at about 5 weeks, but some flutter to the ground before climbing up into trees. They can fly weakly at about 6 weeks. At 9 to 10 weeks young can capture insect prey by themselves. Families remain loosely associated during summer before young disperse in the autumn. Adults tend to remain near their traditional nesting territories, while juveniles disperse widely, as much as 100 to 200 kilometres (60 to 125 miles). Mortality: Spotted Owls are long-lived, with captive Owls of 21 years being known. Mortality in the wild is thought to be very high (60 to 95%) for juveniles, especially during the dispersal stage. Adult mortality is estimated at 5 to 20% annually. Natural predators of the Spotted Owl include the Great Horned Owl, which preys on both adults and young; the red-tailed hawk, which preys on young; and the common raven, which may destroy eggs. Many juveniles starve to death. It is thought that Barred Owls will outcompete Spotted Owls for habitat, by being more aggressive, when the two species come into contact. The Spotted Owl may be the most publicised of all endangered species in North America. Because of its dependence on large tracts of old-growth coniferous forests, management for this owl has caused tremendous turmoil in the forest harvesting industry, and has spawned an incredible amount of research - too much to go into here. Habitat: The Spotted Owl is a bird of dense, dark, old-growth or mixed mature and old-growth coniferous forests. Forests are usually dominated by firs or Douglas-fir, but they also use mature hardwood forests of cottonwoods, alders, oak, and sycamore, especially along steep-walled river valleys. They prefer an uneven and multilayered canopy. In one Oregon study, 98% of 636 sites were in old-growth forests (over 200 years old). Virtually all foraging and roosting was done in old-growth, with recently cleared or burned forests not used at all. Some nesting occurs in older second-growth (70 to 140 years old). They prefer shaded mountain slopes and canyons over flat plateau areas.

Great Horned Owl

Great Horned Owls are sometimes known as Hoot Owls, Cat Owls or Winged Tiger. Description: Great Horned Owls can vary in colour from a reddish brown to a grey or black and white. The underside is a light grey with dark bars and a white band of feathers on the upper breast. They have large, staring yellow-orange eyes, bordered in most races by an orange-buff facial disc. The name is derived from tufts of feathers that appear to be "horns" which are sometimes referred to as "ear tufts" but have nothing to do with hearing at all. The large feet are feathered to the ends of the toes, and the immature birds resemble the adults. Females are 10 to 20% larger than males. Size: Length 46-63.5cm (18-25") Wingspan 91-152cm (36-60") Weight 900-1800g (32-63� oz) Voice: Great Horned Owls have a large repertoire of sounds, ranging from deep booming hoots to shrill shrieks. The male's resonant territorial call "hoo-hoo hoooooo hoo-hoo" can be heard over several miles during a still night. Both sexes hoot, but males have a lower-pitched voice than females. They give a growling "krrooo-oo" or screaming note when attacking intruders. Other sounds include a "whaaa whaaaaaa-a-a-aarrk" from disturbed birds, a catlike "MEEE-OWww", barks, hair-raising shrieks, coos, and beak snapping. Some calls are ventriloquial. Most calling occurs from dusk to about midnight and then again just before dawn Hunting: Great Horned Owls hunt by perching on snags and poles and watching for prey, or by gliding slowly above the ground. From high perches they dive down to the ground with wings folded, before snatching prey. Prey are usually killed instantly when grasped by its large talons. A Great Horned Owl may take prey 2 to 3 times heavier than itself. They also hunt by walking on the ground to capture small prey or wading into water to snatch frogs and fish. They have been known to walk into chicken coops to take domestic fowl. Rodents and small rabbits can be swallowed whole while larger prey are carried off and ripped apart at feeding perches or at the nest. Birds are often plucked first, and legs and wing tips discarded. An extremely wide range of prey species (at least 253 identified) are captured, but rabbits and hares are its preferred prey. Mammalian prey includes all coexisting rodents, squirrels, mink, skunks, raccoons, armadillos, porcupines, domestic cats and dogs, shrews, moles, muskrats, and bats. Bird prey includes all other Owls (except Snowy Owl), grouse, woodpeckers, crows, turkeys, pigeons, Red-tailed Hawks, bitterns, Great Blue Heron, ducks, swans, gulls, etc. Reptiles include snakes, turtles, lizards, and young alligators. Amphibians include frogs, toads, and salamanders. Other foods include fish, large insects, scorpions, centipedes, crayfish, worms, spiders, and road killed animals. Pellets are very large, about 7.6 to 10.2 cm (3- 4") long and 3.8 cm (1�") thick. Pellets are dark greyish-black and compact. Skulls as wide as 3 cm (1.2") are regurgitated whole. Pellets are regurgitated 6 to 10 hours after eating. Breeding: Nesting season is in January or February when the males and females hoot to each other. When close they bow to each other, with drooped wings. Mutual bill rubbing and preening also occurs. They do not build a nest of their own but utilise the nests of other birds such as the hawk, crow and heron. They may also use squirrel nests, hollows in trees, rocky caves, clumps of witches broom, abandoned buildings, or on artificial platforms. They are extremely aggressive when defending its nest and will continue to attack until the intruder is killed or driven off. Normally, two to four eggs are laid and incubated by the female only for 26-35 days. Young start roaming from the nest onto nearby branches at 6 to 7 weeks, when they are called "branchers", but cannot fly well until 9 to 10 weeks old. They are fed for another few weeks as they are slowly weaned. Families remain loosely associated during summer before young disperse in the autumn. Adults tend to remain near their breeding areas year-round while juveniles disperse widely, over 250 km (150 miles) in the autumn. Territories are maintained by the same pair for as many as 8 consecutive years, however, these Owls are solitary in nature, only staying with their mate during the nesting season. Average home ranges in various studies have been shown to be approximately 2� square kms (1 square mile). Mortality: A long-lived Owl, captive birds have been known to live 29 to 38 years, and wild Owls up to 13 years. Most mortality is related to man - shootings, traps, road kills and electrocutions. The only natural enemies are other Great Horned Owls and, occasionally, Northern Goshawks during disputes over nest sites. Habitat: Great Horned Owls have adapted to many different places and climates. They occur in habitats from dense forests, deserts and plains to city parks. They have been known to inhabit the same area as the diurnal red-tailed hawk.

Northern Pygmy-Owl erruginous Pygmy-Owl Boreal Owl Flammulated Owl Whiskered Screech Owl Elf Owl Northern Hawk-Owl

Masked Owl

The Masked Owl is the largest and most powerful representative of the genus Tyto in Australia and the female of the Tasmanian race is the largest in the world. The dark Tasmanian birds are still reasonably common, but their mainland relatives have declined alarmingly. They are also known as Cave Owls, or Tasmanian Masked Owls. Description: Upperparts are blackish-brown, finely freckled with white and with some white spots. There is buff barring in the wing and back feathers. The underparts whim to very pale buff, and there are black spots on the breast and flank, (usually more than on Barn Owl). The facial disc is white (may be buff to chestnut in examples of the large Tasmanian form) with a blackish-brown edge, somewhat rufous or brown around the eyes, which have a brown iris. The Beak is white and feet off-white to brownish. The female is considerably larger than the male. Size: Mainland race: Female 38-46cm (15-18") Male 33-41cm (13-16") Tasmanian race: Female 43-57cm (17-22") Male 35-42 cm (14-16�") Wingspan up to 129cm (51") Weight up to 1260g (44� oz) Voice: A Masked Owl's call is similar to that of Barn Owl but louder, deeper and harsher. There are also a variety of other calls associated with breeding. Hunting: Masked Owls predominantly feed on terrestrial mammals, with part-grown rabbits making up a large proportion of the Tasmanian bird's diet. They will also eat Sugar Gliders, Ringtail and Brushtail Possums, Bush rats, Antechinus, birds and domestic fowl. Masked Owls prefer to hunt in open country, by perching on fenceposts and low branches. Breeding: Most eggs are laid from March to July, but they may breed in other parts of the year depending on food supply. During courtship, both male and female birds take part in spectacular flights over the nesting territory, with the male giving constant cackling and chattering calls, after which the female enters the nest hollow, which is often an isolated tree. She is then fed by the male in the hollow. 2-4 dull white, rounded eggs are layed measuring 43-49mm (1.7-1.9"). These are incubated for about 42 days. The young are covered in white down, then a creamy down, and are fledged in 10-12 weeks. Fledged Masked Owls have only traces of down, and remain in the nest vicinity for several weeks. Habitat: Forest and open woodland, but also in treeless country where cave shelters are available. Roosts by day in tree hollows, caves, or heavy foliage.

Sooty Owl

These elusive and robust Owls have the largest eyes of any Masked Owl. They are the great dark Owls of the southern Australian rainforests, where they live in the deepest gullies. Known also as Black Owls or Dusky Barn Owls, they are rarely seen or heard, for few people venture into their forbidding habitat at night. The Sooty and lesser Sooty Owls are the most nocturnal of all Australian Owls. Description: A medium large, sooty black Owl with very large, dark eyes set in a round racial disc. The upperparts are sooty black, finely spotted white on the head with larger but sparser white spots on the wings. The Facial disc is large, round and sooty black through to dark grey or silver and is heavily edged black. The underparts vary from sooty black to dark grey, (never as dark as the upperparts) finely spotted with white. The Belly is always paler than the breast. The tail is very short, the legs feathered and eyes very large with a black iris. A Sooty Owl's Bill is horn coloured and feathered almost to the tip. Toes are dark grey and the large talons black. Sexes are similar in plumage and Females are usually slightly larger than males. They are distinguished from lesser Sooty Owls by much larger size and darker plumage, sparser white spots on upperparts and darker underparts which have white spots on a dark background where the lesser Sooty Owl has dark chevrons on a pale background. Size: Female - Length 44-51 cm (17-20") Weight 750-1000g (26�-35 oz) Male - Length 37-43 cm (14�-17") Weight 500-700g (17�-24� oz) Voice: The characteristic call is a piercing downscale shriek, lasting for upwards of two seconds. It has been likened to the sound of a falling bomb without the final explosion and the call is now widely known as the 'bomb whistle'. There are also various other calls associated with breeding and nesting. Hunting: The Sooty Owls is a powerful hunter and takes some remarkably big prey, a high proportion being arboreal. This contrasts not only with the lesser Sooty but with all other Tyto Owls, which take most of their prey on the ground. The huge eyes of both sooty Owls compared with other Tyto Owls suggests a greater reliance on vision. Sugar Gliders and Ringtail Possums make up a high proportion of the prey but a wide variety of other mammals have been recorded. There are no records of hunting methods. The male does all the hunting during breeding and usually brings one large prey item per night. Breeding: The season is variable, with most eggs laid from January through to June but there are some records of laying in spring (August-September). Males often become more noisy at the start of the season, giving frequent 'bomb whistles'. The male feeds the female in the hollow, engaging her with soft, high-pitched trilling before passing over the prey. The nest is usually in a large hollow in a living tree at any height from 10 to 50 metres (33-164 feet). There are a few records of nesting in caves. Females occupy the hollow for many weeks before laying, flying out only briefly during night. A female in a cave nest site rarely leaves at all. 1 or 2 dull white eggs are laid, measuring 44-52mm (1.7-2") by 36-41mm (1.4-1.6"). Incubation is around 42 days. The young are covered in sooty grey down and are fledged in about 3 months. The newly fledged Sooty Owl is dependent on its parents for up to a month. Habitat: Deep moist gullies in eucalypt forest, usually with big, old, smooth-barked gums and an understorey of tree ferns and Lilly Pilly. They may move into drier forest to hunt but they need the primary habitat for roosting and breeding. They are Territorial and sedentary throughout the year.

Lesser Sooty Owl

These smaller cousins to the Sooty Owl of the south inhabit the north Queensland rainforests. They are sometimes called the Silver Owl. Description: A small to medium, sooty black Owl with silvery white underparts. They have many similarities to the Sooty Owl but are lighter in colour and noticeably smaller. The upperparts are sooty black or grey-brown with large numbers of fine s ilvery white spots on the head and wings. They have a large round facial disc with silvery white shading to black around the eyes - the face is heavily edged black. Underparts are silvery white with many fine dark grey or sooty black chevrons, particularly on the breast. Lesser Sooty Owls have very short tails. Their eyes are very large with a black Iris. The beak is pale horn. Toes are pale grey with black talons. Sexes look similar but the female is usually slightly larger. Size: Female - Length 35-38cm (14-15") Weight up to 540g (19oz) Male - Length 31-35cm (12-14") Weight up to 450g (16oz) Voice: A piercing downscale whistle, which can sound like a shriek at close quarters. This is similar to the Sooty Owl, but less powerful, and quite often with a slight step in the downward progression of the call. There are also a variety of trills and chirrups associated with breeding. Hunting: Lesser Sooty Owls hunt mainly small mammals, but also take insects and some birds. They generally hunt from low perches and take prey on the ground. Breeding: The season is very variable and dependant on rain. Eggs are laid in any month, but most records of laying are from March to May. Pairs usually become more noisy at the start of the season with frequent 'bomb whistling'. Sometimes several pairs may be within earshot of each other, their calling clearly territorial. Pairs perch close together with high-pitched trilling. The nest is usually a large hollow in the trunk or a main limb of a living tree, often Rose Gum. The female may occupy the hollow for many weeks before laying, going out briefly only once or twice each night. Generally 2 eggs are laid, but sometimes 1. They are dull white rounded ovals of about 41mm (1.6") by 36-39mm (1.4-1�"). Incubation is 40-42 days and the young have downs of sooty grey. Fledging is at about 3 months. Newly fledged young are indistinguishable from adults and remain in the breeding territory at least for several weeks and are fed by the parents. Habitat: Mountain rainforests of north Queensland.

Grass Owl

Description: Upperparts are dark brown with pale spots, with buff bars in the wings, which can appear bluish-grey in flight. The underparts are creamy white to pale buff with some brown spots. The facial disc is white and may have pale buff marking. There is a brown mark in front of each small brown eye, with the edge of disc dark brown on top but buff on sides and bottom. The legs very long compared with other Tyto species (about fifteen per cent longer), with feathering on the lower parts reduced to a few bristles. The feet are greyish and the Bill is light brown. The legs are carried horizontally in level flight but part lowered during take-off, landing and aerial manoeuvres. They can be distinguished from all other Tyto Owls by their long legs with protruding feet in flight, long wings, and terrestrial habits. The female is larger than the male. Size: Female 35-38cm (14"-15") Male 32-36cm (12�-14") Wing Span up to 116cm (45�") Weight up to 450g (16oz) Voice: Appears to be more silent than the Barn Owl, the normal call being a hissing scream similar to a Barn Owl. In loudness and harshness it is about midway between a Barn Owl and Masked Owl. Hunting: Numerous species of rodent have been recorded as prey, long haired Rat and Cane Rat being the most common. Grass Owls, even more than Barn Owls, are specialist hunters of small rodents and rarely take any other prey. Even though they weigh much the same as Barn Owls, their wings are considerably longer, reflecting their method of hunting which is done entirely in flight and never from perches. Hunting is by low, quartering flight followed by a quick plunge into the grass when prey is detected. In typical Grass Owl areas, prey is hidden from sight and located and taken through the combined use of hearing and the very long legs. Breeding: Grass Owls probably breed at any time of year if conditions are favourable but, in coastal parts of northern Australia, laying usually occurs between March and June. The nest is on the ground in dense tussocks of grass or sedges, particularly Bladey Grass, usually well away from trees. The nest is a flimsy platform of grasses which soon becomes trampled and obliterated. It is enveloped in grasses and is approached by a series of tunnels, usually at least three, which the Owls make by pushing their way through on foot. One of these is normally the main one and the grass at its entrance becomes flattened from repeated landing and departures. In the nest, 3-8 dull white eggs are layed. they are slightly more pear-shaped than other Tyto Owls and measure 40-44mm (1.6-1.7") by 29-32mm (1.1-1�"). Incubation is thought to be around 42 days (assumed to be similar to the African Grass Owls). The young have a first down of white and second of warm golden brown. Fledging is at about 2 months. Long before this, the female stops brooding them and they walk away from the nest to hide in the grass, returning at night when the adults bring in food. All young appear to fledge in dark plumage, indistinguishable from adult females. Habitat: Tall grasslands and swampy country. Dense, well-established tropical grasslands, particularly with Bladey Grass or sedges and around canefields. Also desert grasslands at times of plagues of long haired Rats. Although rare, they have colonial tendencies and up to 30 have been recorded in an area of under 100 hectares. They are rarely seen unless flushed and are generally thought to perch only on the ground but there have been sightings of birds perching on topmost spray of young pines.

Powerful Owl

Australia's largest Owl, the Powerful Owl is both enigmatic and unpredictable. This does not, however, take away from this fascinating bird's beauty. Powerful Owls are sometimes called Eagle Owls. Description: The colour of the upperparts varies from grey-brown to dark brown and may appear bluish in dull light. The forehead is creamy white and the crown and nape finely spotted creamy white. The back and wings are irregularly barred, also in creamy white. There are approximately six narrow creamy white bars across the tail. A Powerful Owl's Facial disc is dark brown, and surrounds bright yellow eyes with prominent eyebrows and a powerful, bluish horn beak with bristly feathers at its base. Underparts are dull white with broad brown chevrons from throat to vent, arranged in irregular bars. The tail is broadly barred brown and white. The legs are feathered to tarsus and end in huge yellow feet with brown talons. Males are usually considerably bigger than females with broader heads and flatter crowns. Powerful Owls always roost in the open where quite close human approach may be tolerated. Its reaction to human presence at night is often one of frozen immobility which may be maintained for hours, making it hard to, find outside breeding season. Size: Female - Length 45-54cm (18-21") Wingspan 112-132cm (44-52") Weight 1050-1600g (37-56�oz) Male - Length 48-65cm (19-25�") Wingspan 115-135cm (45-53") Weight 1130-1700g (40-60oz) Voice: The Powerful Owl's voice is a slowly uttered, rather mournful, loud, two-syllable note that sounds like "woo-hoo", each note lasting just over half a second with a brief pause in between. The second note is often slightly higher pitched than the first, more so in the female than in the male. The male's voice is slightly deeper than female's. There are also various other calls associated with breeding and nesting, including a strange, tremulous, sheep-like bleating uttered be either sex around the nest. This may show anger (when it becomes almost a snarl), anxiety or be used by the female when the male is returning with food. Hunting: The Powerful Owl hunts from perches, mainly on slow-moving arboreal mammals and large birds which are caught at their roosts. They will occasionally take insects and prey on the ground. Prey recorded by David Hollands in central Victoria include Common Brushtail Possum, Mountain Brushtail Possum, Ringtail Possum, Sugar Glider, Tuan, Brown Antechinus, Rabbit, House Mouse, Kookaburra, White Cockatoo, Galah, White-winged Chough, Australian Magpie, Pied Currawong and Australian Raven. Birds may be roughly plucked before eating but never as thoroughly as with diurnal birds of prey. Large prey is often not eaten until the night after capture and Owl roosts with one foot on prey which is draped over branch. The reason for this not known but this also occurs commonly with Rufous Owls and occasionally with Barking Owl. Breeding: A punctual winter breeder with each female typically laying on almost the same date each year. Most eggs are laid from the second week in May to the third week June. Males begin calling in late February or early March. Around this time, pairs begin to roost closer together, at first in same tree and then on same branch, often still some distance from the potential nest site. The nest is a large hollow, nearly always in the trunk or broken off top of a big eucalypt. In tall forest this is usually at the head of a gully or on a hillside at heights from 20-45 metres (65�-147� feet). Where tall trees are not available, the nest may be in open forest or among part-cleared timber at levels as low as 6 metres (19� feet). Usually 2 eggs, rarely 1, are laid at 4 day intervals. They are almost spherical and are dull white, measuring 49-56mm (1.9-2.2") by 43-46mm (1.7-1.8"). Incubation is about 38 days with the male rarely visiting the nest after laying - the female leaves the hollow to take food from him. The young have first and second downs of white, becoming stained in the nest. The Beak and feet seem disproportionately huge in early weeks. They are brooded constantly by the female until about 4 weeks when she abruptly ceases to brood by day and her visits become progressively shorter at night. First flight is at 7 to 8 weeks while still partially downy. After fledging, the young remain with their parents for weeks or months, roosting near or with one of them, sometimes remaining with parents in late autumn and this may inhibit them from breeding in the following season. Powerful Owls have always been thought to be shy and not aggressive at the nest but this needs considerable qualification. Females are certainly shy and may desert a nest after minimal human disturbance, particularly early in the season. Some males, however, may be extremely aggressive in the breeding season, attacking humans with great ferocity even at a considerable distance from the nest. This is most likely when there are young in the nest but may occur even before laying. Habitat: Typically wet and hilly sclerophyll forest with dense gullies adjacent to more open forest. Will also occur in smaller, drier forest, provided that there are some large tree hollows and an adequate supply of prey.

Boobook Owl

The Boobook, is the smallest and most familiar of the Owls in Australia. It is more often heard than seen due to its familiar two note call, sometimes repeated for hours on end, which has been likened to that of a European Cuckoo. These sometimes playful little Owls are also known as Mopoke, Morepork, Spotted Owl, and Marbled Owl. Description: Upperparts are pale to dark brown, depending on locality or individual variation, with white spots on the wings and back. The underparts are cream to buff with broad pale to dark brown streaks and mottling, the indistinct facial disc being much paler than general colour with a large dark patch behind eye. the bill is a blue-grey, and feet pale blue-grey. Adults have a greenish-yellow iris, while a juvenile's is brown. The females are slightly larger and more richly coloured. Immatures are paler than adults. As many as 10 races were recognised in earlier days, but Schodde and Mason, in their Nocturnal Birds of Australia (1980), reduced them to four, comprising two main populations extending over the continent divided on a line following the western footslopes of the Great Dividing Range with the nominate race boobook (A) to the east and race ocellata (B) to the west. They note that the western birds are of a more sandy red hue than the eastern birds living in similar country; also that the western birds are smaller and paler in the north, while the trend in the east is reversed. However, an isolated population is identified in the dark and humid rainforest of the high country of north-eastern Queensland, race lurida (C), which are smaller and darker. The Tasmanian birds, race leucopsis (D), are even smaller and conspicuously spotted. They have golden-yellow eyes and place yellow toes like their New Zealand cousins, and some migrate to the mainland as far as Sydney to winter. Size: Female - Length 27-36cm (10�-14") Wingspan 70-85cm (25�-33�") Weight 194-360g (7-12�oz) Male - Length 23-36cm (9-14") Wingspan 70-85cm (25�-33�") Weight 170-298g (6-10�oz) Voice: Normal call is a brief double hoot with the second note pitched lower than the first, each note lasting for about a quarter of a second with a half second gap in between. There is usually a brief pause and then the call is repeated at a frequency of about twenty calls a minute. Calling may last for only a minute or two or may go on for hours. Boobooks also call in a low, soft 'pot pot pot por pot pot por'. This is a call between mated birds but its use is not confined to the breeding season. The breeding call is a tremulous braying call, the equivalent of the bleating call of the Powerful Owl. Hunting: The type of prey taken seems to vary greatly with individual birds, the majority of Boobooks taking mostly insects and arthropods. Some Boobooks have been known to hunt mainly mice or small ground birds. Flying insects are taken by hawking flight through and above trees, taking only one insect each flight, and transferring it to the beak before bringing it to the nest or landing to eat it. Other insects are snatched from foliage or caught on the ground. Boobooks often hunt around street lights and along roads where many are hit by cars. Breeding: The breeding season is August and September almost throughout Australia. Pairs perch close together with the male giving 'pot pot por' call for long periods. This may commence well before start of season. One or both birds may roost in nest hole together for weeks before breeding starts but these out-of-season roosts are not always chosen as the eventual nest site. The nest can be a wide variety of tree hollows - the tree may be alive or dead with a hole in a limb or the main trunk, upright or sloping. The male cleans out the hollow before eggs are laid - usually 2 or 3, rarely up to 5. The eggs are white and almost round, being 40-45mm (1.6-1.8") by 32-37mm (1.�-1�"). They are laid at 1 to 2 day intervals and are incubated for 35 days. The young have white down and are fledged in 5 to 6 weeks. Like other Ninox Owls, they leave the nest well below full size and with abundant down. They are probably dependent on the parents for 2 to 3 months after this. Habitat: Almost anywhere where there are trees. Eucalypt forest and woodland appears to be the optimum habitat but also mallee, mulga, semi-desert, tree-lined creeks, residual timber on farmland, leafy suburbs, offshore islands. They are generally absent from dense rainforest, except for the Red Boobook of north Queensland.

Rufous Owl

The Rufous Owl, widespread in New Guinea, is uncommon in Australia and restricted to the tropical north. They are a wary unobtrusive bird, elusive and unpredictable. Descriptio n: A large, rufous-coloured Owl of tropical rainforest. The forehead, crown, nape, back and upper wings are dark rufous, finely barred light brown. The upper tail is similar but with broader bars. The facial disc is indistinct and blackish brown. The throat, breast, and belly are rich rufous, finely and closely barred cream, the bars becoming broader and fewer from the throat backwards. Under the wings and tail is light brown, broadly barred cream. Rufous Owls have a long tail and feathered legs with pale yellow or creamy toes and black talons. Iris is yellow and the bill is pale horn with short black bristles at the base. The male always larger than the female and tends to have a broader, flatter head.Newly fledged young are much smaller than the parents and still part downy. Young adults tend to be more broadly barred than older birds with dark sepia rather than rufous colouring. Size: Length 46-57cm (18-22�") Wingspan 100-120cm (39�-47") Weight - Female 700-1050g (24�-37oz) Male 1050-1300g (37-46oz) Voice: Rufous Owls are the least vocal Australian Ninox and call very little outside the breeding season. Pairs at roost may converse very softly. The commonest call is a deep, double hoot, similar in pitch and tempo to the Powerful Owl but more nasal, less ringing and with far less carrying power. A second note may be at same or a slightly higher pitch than the first. Female's calls are always slightly higher. Occasionally a single hoot may be used. The female has sheep-like bleating call similar to the Powerful Owl used when the male returns to the nest with food. Hunting: The Rufous Owl is an extremely versatile and powerful hunter taking a variety of prey from beetles to large birds and flying foxes. Prey recorded include Brush-turkey, Scrubfowl, Papuan Frogmouth, Blue-winged Kookaburra, White Cockatoo, flying fox, Sugar Glider, beetles, phasmids, several species of heron, ducks, parrots and, remarkably, crayfish. Prey have been seen to be taken from perches (Scrubfowl), by snatching from foliage in flight (phasmids), in aerial chases (flying fox) and by hawking like a giant flycatcher (beetles). The crayfish were presumably taken when stranded by falling floodwater. Breeding: Like most Ninox, the Rufous Owl has a regular breeding season with egg laying varying from June in the Northern Territory to September in north-east Queensland. Individual females appear to lay at very much the same date each year. The presence of the previous seasons young may sometimes inhibit nesting for that season. As nesting approaches, both birds roost close together, often on the same branch. After dark, the male calls with a double hoot and the female may fly to him with excited bleating trills. Pairs perch side by side and the male preens the nape of the female's neck while she picks at his toes with her bill. Both sexes may be fiercely aggressive to humans in defence of the nest, which is a large hollow in the trunk or a main limb of a big tree, usually living but sometimes dead. Most nests are high, at about 30 metres (98 feet), but occasionally low at down to less than 3metres (10 feet). The male cleans out the hollow and female only enters immedia tely before laying 2 (or occasionally 1) eggs. There are 3 days in between laying the dull white, almost spherical eggs. They are 49-54mm (2") by 44-48mm (1.9"). Incubation is 37 days and the Young have a first and second whitish down. Fledging is about 50 days while still partly downy. The young remain dependent on adults for several months and this period may extend into the next breeding season. Habitat: Rainforests, monsoon forest; wet, forested gullies, and adjoining woodland. Roosts by day in leafy trees.

Barking Owl

The most hawklike of Australian Owls, the Barking Owl is known for its dog like call and is often called the Winking Owl. Description: A medium-sized brown Owl with white spots on its wings, a strongly streaked breast and brilliant yellow eyes. They are usually seen roosting in open in deep shade. The forehead, crown, nape, and facial disc are brown, varying in shade from dark to light sandy. Some birds have thinly pencilled white eyebrows. The upper wings and back are brown with large white spots and the upper tail inconspicuously barred brown. The throat is brown, white streaked brown, or white. Throat feathers are erectile giving a bearded appearance in white-throated birds. The breast and belly are white, heavily streaked brown with feathering extending onto the pale yellow legs. Under the tail is broadly barred white and brown. Eyes are large and have a yellow iris. The bill is dark horn or blackish. Barking Owls characteristically roost in isolated stands of trees in open country, often faithful to same spot for months or years. They are attracted to water and may bathe regularly early in the morning. Size: Length 35-45cm (14-18") Wingspan 85-100cm (33�-39�")Weight 425-510g. There is very little difference in size between sexes. Voice: Extremely characteristic, loud and remarkably dog-like double bark, 'wuf wuf' or 'wuk wuk'. Barks are always preceded by a short, low groan but this is audible only at close quarters. Calls are usually given at dusk and dawn, often in yapping choruses between male and female which may go on for several minutes. They do not call for long periods through the night like the Boobook. The female's call is noticeably sharper and shorter than the male's and carries further. Females sometimes use a low, groaning hoot of almost cow-like quality to call to young. A dog-like snarling is used in aggression by both sexes near the nest. Barking Owls are also notorious for their "screaming woman" call - it is described as a scream of terrifying intensity which sounds remarkably lifelike. This is not a common call and more likely to be used outside the breeding season. Its significance is unknown. Hunting: Barking Owls are agile and aggressive hunters, taking a wide range of prey. They hunt earlier in the evening and later in the morning than any other Australian Owl, taking many types of birds, including House Sparrow, Magpie Lark, small pigeons, Blue-faced Honeyeater, Laughing and Blue-winged Kookaburra, Red-rumped Parrot, Tawny Frogmouth, Australian Magpie, White- winged Chough, White Cockatoo and several species of duck. In southern Australia the Rabbit is now the main prey, but gliders, small possums, bats and rodents are also taken. Like other Ninox Owls they take many insects, particularly outside the breeding season, beetles and crickets being most common. Most prey appears to be taken on the ground or when perched. Breeding: A late winter breeder with most eggs laid July to September. Cape York and Arnhem Land birds may be a little earlier but there seems to be no time difference between north Queensland and Victoria. Pairs perch close together at the start of the season with bouts of animated calling. The male appears to choose the nest site but rarely visits after laying. The nest is a large hollow up to 30 metres (98� feet) high, in the trunk or large limb of a tree. They will occasionally nest in deep forks of trees, rock crevices and rabbit burrows. The same site is often used for many years. The female occupies the hollow immediately before laying 2 or 3, occasionally 1, white, dull, almost spherical eggs 43-50mm (1.7-2") by 36-41mm (1.4-1.6"). They are laid at 2-3 day intervals and incubated by the female alone for approximately 36 days. The young have first and second downs of white and are fledged in about 35 days. All Ninox Owls leave the nest while still partly downy, but fledgling Barking Owls are downiest of all. Young roost near and remain with parents for several months. Habitat: Ideal habitat is open country with a choice of large trees for roosting and nesting. In southern districts, Barking Owls choose creeks and rivers, particularly with River Red Gums, isolated stands of trees and open woodland. In northern Australia they favour paperbark swamps as well as previous habitats. Although they are generally wary at their nest, they may become very accustomed to humans, nesting close to farm buildings and even in streets in towns. They have a distinct preference to be close to water.

Hawk Owl

The Christmas Island Hawk-Owl is one of three nationally threatened birds of prey in Australia. The total population of the species is contained on a single island and estimated to be less than 1000. Description: Resembles a small, red-brown Boobook Owl. The breast is whitish and finely barred rufous. Eyes are yellow. Size: Length 26-29cm (10.2-11.4") weight 160-200g (5.6-7 oz) Voice: The main call is similar to the Boobook Owl, being two hoots, the second being slightly lower in pitch. This call is often repeated many times in just a few minutes. Other calls noted for these Owls include a shrill, trilling call given by begging young, and a Chirring given by the female requesting food from her mate during courtship and nesting. During courtship, the male gives a "Por Por" call when close to the female. The "Kar Kar" call is made by the male when delivering food to the female and nestlings. Hunting: The Christmas Island Hawk Owl eats mainly insects, usually by snatching them from foliage. They have also been observed hawking for insects around street lights. Other prey recorded include juvenile black rats, and small lizards and birds. Breeding: At one nest, the single chick took about 77 days from hatching to fledging. Habitat: They inhabit the tropical rainforest, monsoon forest and scrub of Christmas Island.

Tawny Owl

Description: There are two basic colour types of Tawny Owls, one being rich chestnut-brown, the other having greys instead of deep browns. Intermediate birds are variously tawny-buff, buff-brown or greyish-brown in coloration. The upperparts of the brown birds are of a rich tawny or sometimes a more tawny-chestnut hue, streaked, mottled and vermiculated with dark brown and blackish-brown, and mottled with lighter brown or tawny-buff. Bands of buff or whitish-buff mottling run back and outwards across the crown from the central upper edge of the facial disc. Black-brown mottling adjacent to these bands usually highlights this pattern. The shoulders are variably tipped and edged whitish, forming ragged pale 'braces'. The face is either pale rufous-buff, or deep buff with a tinge of rufous. The semi-circles and narrow ring surrounding the eyes are buff. The facial ruff is densely flecked and edged dark brown, forming a very narrow, dark edge to the facial disc. The bill is pale olive-yellow and the very large eyes have bluish-black irises. Underparts are whitish or buff. Wings are barred tawny-buff or buff and blackish-brown with brown mottling on the buff areas. Tail feathers are tawny to tawny-chestnut, with the outer feathers barred dark brown. All tail feathers are tipped greyish-white or buffish. The underwing is creamy-buff with a dingy brown wash and grey-brown bars across primaries and secondaries. There is a rufous-yellow wash on the tips of the underwing-coverts which are lightly streaked dark brown with broad black-brown tips to primary coverts forming a dark semi-circular mark near the bend of the wing. Legs are feathered and white with some brownish speckling. The claws are blackish with dirty white bases. Grey-brown birds have the same basic pattern as brown birds, though all the browns are replaced by a much greyer hue.

Size: males length: 41-43.5cm (16-17")
wing span: 91-95cm (35.8-37.4")
weight: 410-550g (14.5-19.4 oz)

Females length: 435-460 mm (17-18")
wing span 94-105cm (37-41.3")
weight: 410-800g (14.5-28.2 oz)

Voice: The normal 'song' - the familiar hooting of the male has several functions: it is a territorial call, a courtship call, and an announcing call used when bringing food to the female. It consists of a long drawn out hooo, a pause, an abrupt and subdued ha, followed at once by a prolonged and resonant final phrase huhuhuhooo. Sometimes, the female makes a similar hooting sound to the mating male, however, the female's hooting is less clearly phrased than the male's, the last phrase having a more wailing quality, approximately wow-wow-hooo. Andersen (1961) calls these particular sounds the incomplete song, stating that they are commonly uttered by either sex. He described it as a grating, hoarse version of the normal song.

The contact call kewick and its variants is the most frequent utterance of the female, but it is also used by the male. In spring the female may answer the male's hoot with kewick as a kind of duet. When the female gives this call from the nest the male generally responds soon afterwards by bringing prey to her, loudly announcing his arrival.

A similar call is also made by the parents as a contact call when bringing prey to the fledged young. The young will answer with their cheeping call. Many other calls have been heard during courtship and in territorial disputes.

Hunting: Tawny Owls hunt almost entirely at night, usually waiting quietly on a perch, watching and listening. After detecting a prey animal moving in the grass, the Owl glides down or drops onto it and, at the moment of impact, extends its wings to cover the victim, which is usually killed immediately by the powerful feet and claws. Sometimes a blow from the beak at the base of the victim's skull is also used. Hunting on the wing alternating with hunting from a perch has been recorded in Sweden. Tawny Owls have been reported to beat their wings on bushes to startle birds into flight. They also snatch birds, and occasionally bats, from their roosting perches. Incubating birds, such as Blackbirds, Woodcocks and pigeons, have been picked off their nests.

Prey taken include rabbits, moles, mice, shrews, voles, and other rodents. They also eat earthworms, insects (beetles especially), birds, frogs, fish, lizards, molluscs, and crustaceans. Pellets normally range from 30-70mm (1.2-2.75") in length and 18-26mm (0.7-1") in width, and are usually of a loose texture and grey when dry.

Breeding: Tawny Owls remain within their nesting territory all the year round and pair-bonds last for life. They are generally monogamous but some males are known to be polygynous.

The first territorial fights occur as early as October and November, the male determining the territory, the female the nesting hole. The transition from autumn to winter is marked by a final establishment of territories and pre-breeding behaviour. The female and male tend more and more to roost together. Courtship feeding begins in the winter period (December to February), becoming progressively centred on the future nest site. In Europe the Tawny Owl usually begins breeding in mid-March.

During courtship the male perches near the female and sways from side to side, then up and down, raising first one wing then the other and finally both together. His plumage is puffed out, making him appear almost round, then tightly compressed. Meanwhile he grunts softly, sometimes sidling a foot or so along the branch and back again. He may indulge in wing-clapping and when pursuing the female will utter screeches, mewings, groans and rattles. The female may puff out and quiver her feathers.

Tawny Owls will nest in a natural hole or a nest box in a tree, but occasionally nests have been found on ledges of old buildings and in chimneys. They will also use the old nest of a crow, Magpie, Sparrowhawk or Buzzard, and sometimes a squirrel's drey. They will also use a Raven or Buzzard nest on a cliff or simply a bare ledge. According to Donald Watson, ground nests are quite common in Galloway, in south -west Scotland.

Tawny Owls lay from two to six eggs, but sometimes only one. The eggs are almost round and pure white and are about 46.7 x 39mm (1.84 x 1.54"). Normally, they are laid at intervals of 48 hours, and are incubated for 28-29 days by the female alone. When the young have hatched, the male brings more food, either to the nest or to the female waiting nearby. Once the chicks are 6-7 days old the female may leave the nest only to hunt, otherwise remaining near the young. Fledging occurs after 28 to 37 days. Tawny Owls are dependent on their parents for food up to three months after leaving the nest. As the young owls gradually learn to fend for themselves they also establish territories.

Territory size depends on terrain and prey availability. Territories may range from 12 ha (30 acres) in closed woodland, through 65-75 ha (162.5-187.5 acres) when living in beechwood with little lesser vegetation, to 102 ha (255 acres) in Norway, where the prey density is far less than in England or Belgium. The Tawny Owl defends its territory vigorously against neighbours with 'song', with threatening behaviour or in flying skirmishes. Predatory mammals, too, such as cats, foxes and dogs, are driven from the vicinity of the nest. Occasionally a Tawny Owl female with nestlings may attack a human approaching the nest, even in daylight, and may even draw blood with its talons.

Mortality: The Tawny Owl reaches sexual maturity within a year and can, therefore, breed during the first year of its life. In central Europe, one ringed Tawny Owl lived 18 years and 7 months and in Britain one caged Tawny Owl survived 27 years. Many young Tawny Owls lose their lives when trying to secure a territory inside the parental one - they must either starve or move out. The most common fatalities connected with man are collisions with vehicles, trains or wires, and getting trapped in buildings.

Habitat: Tawny Owls usually breed in broadleaved woodland and forests and open parklands although occasionally they inhabit coniferous forests. Though woodland is their preferred habitat, they are adaptable and have even taken up residenc e in cities such as London and Berlin where there are large wooded parks and gardens.

Spectacled Owl

Description: Spectacled Owls are dark brown with a yellow-ocher belly, a white patch on the front of the neck and a dark brown belt across the breast. White "spectacles" around their yellow eyes give them their name. They are not strictly nocturnal.

Size: Length 43-46cm (17-18") Weight male 453-680g (16-24oz) female 680-906g (24-32oz)

Voice: a long rapid thumping call.

Hunting: Spectacled Owls eat bats, birds, mice, insects, crabs and frogs.

Breeding: They nest in tree hollows, where 1-2 eggs are laid. Chicks leave the nest before they can fly well.

Habitat: Tropical rainforest. They prefer to live near water.

White-faced Scops O wl

These Owls are also known simply as White-faced Owls.

Description:

Size:

Voice: An extended trilling sound, similar to that of the American Screech Owl, to which they are related. Apparently there is also a rarely heard cat-like cry.

Hunting: Like other small owls, the White-faced Scops Owl is generally insectivorous, although they may take small birds, rodents and other small mammals.

Breeding: They often nest in abandoned stick nests of small hawks and will also use tree hollows. They also use ground nest sites.

Mortality:

Habitat: Scrub and bush.

Barn Owl

Also known as the Delicate Owl, White Owl, or Screech Owl, these pale, nearly worldwide, birds are closely associated with man through their traditional use in the Old Wor ld of barn lofts and church steeples as nesting sites. There are few things as haunting as seeing the ghostly white form of a Barn Owl gliding through the night sky, its total silence broken only by its unearthly screech. The scientific name Tyto alba translates into "a species of white Owl." Description: The Upperparts are light grey with numerous fine dark lines and scattered pale spots on the feathers. There are buff markings on wings and on the back. The underparts are white with a few black spots, occasionally none. Feathering on the lower legs may be sparse. The heart-shaped facial disc is white with a brownish edge, with brown marks at the front of the eyes, which have a black iris. Its beak is off-white and the feet are yellowish-white to brownish. Males and females are similar in size and colour, females and juveniles are generally more densely spotted.

Size: Female: Length 34-40cm (13�-15�")
Wingspan 110cm (43")
Weight 570g (20oz)

Male: Length 32-38cm (12�-15")
Wingspan 107cm (42")
Weight 470g (15�oz)

Voice: The Barn Owl calls infrequently, the usual call being a drawn-out rasping screech. The courtship call of male at nest is a shrill repetitive twittering. Adults returning to a nest may give a low, frog-like croak. When surprised in its roosting hollow or nest, it makes hissing and rasping noises and snapping sounds that are often called bill snapping, but possibly made by clicking the tongue.

Hunting: Barn Owls specialise in hunting small ground mammals, and the vast majority of their food consists of small rodents. In Australia, the introduced House Mouse (Mus musculus) forms the staple diet. in the USA, voles (field mice) are the single most important food (65%) followed by shrews, deer mice and rats. Barn Owls breed rapidly in response to mouse plagues. Other prey may include baby rabbits, bats, frogs, lizards, birds and insects. Prey are usually located by quartering up and down likely looking land - particularly open grassland. They also use low perches such as fence posts to seek quarry. Barn Owls rely greatly on their silent flight and extremely acute hearing to locate prey. The sound of the Barn Owls wings are muffled by a velvety pile on the feather surface. In addition, the leading edges of the wing feathers have a fringe or fine comb which deadens the sound of the wing beats. The silent flight prevents the Owls victim from hearing its approach, and also aids the Owls own hearing. The ear openings are at slightly different levels on the head, and set at different angles. They are covered by a flexible ruff made up of short, densely webbed feathers which frames the face, turning it into a dish-like reflector for sound. This gives the Barn Owl very sensitive and directional hearing, with which it can locate prey even in total darkness.

Breeding: Barn Owls will breed any time during the year, depending on food supply. In a good year, a pair may breed twice. Rodent plagues cause Barn Owl numbers to increase dramatically. During courting, males may circle near the nest tree, giving short screeches and chattering calls. The majority of Australian Barn Owls nest in tree hollows up to 20 metres high. They will also nest in old buildings, caves and well shafts. 3 to 6 eggs are laid (occasionally up to 12) at 2 day intervals. The eggs are 38 to 46mm (1�-1.8") long and 30 to 35mm (1.2-1.4") wide and will be incubated for 30 to 34 days. Chicks are covered in white down and brooded for about 2 weeks, and are fledged in 50 to 55 days. After this, they will remain in the vacinity for a week or so to learn hunting skills and then rapidly disperse from the nest area. Young birds are able to breed at about 10 months.

Mortality: Barn Owls are short-lived birds. Most die in their first year of life, with the average life expectancy being 1 to 2 years. In North America the oldest known Barn Owl in the wild lived to be 11 years, 6 months; in Holland one lived to be 17 years, 10 months old.

Habitat: The Barn Owl is found in virtually all habitats but much more abundantly in open woodland, heaths and moors than forested country. They usually roost by day in tree hollows but have also been found in caves, wells, out-buildings or thick foliage.

Short-eared Owl

In Latin, the word "flammeus" means fiery, flaming, or the colour of fire. Local names for the Short-eared Owl include the Evening Owl, Marsh Owl Bog or Swamp Owl, Grass Owl, Meadow Owl, Mouse-hawk, and Flat-faced Owl.

Description: The Short-eared Owl is a medium-sized, diurnal and nocturnal Owl. When perched it leans forward, more hawklike than other Owls, and appears bulky rather than sleek. The plumage is buffy brown with dark streaks on the chest, belly, and back. Males tend to be lighter in colour than females. This colouring provides good camouflage, but if this fails, a Short-eared Owl will feign death to avoid detection. The wings and tail are strongly barred. The yellow eyes are circled with black and set in whitish or buffy-white facial disks, which are suffused with a ring of brown. The bill is black. The head appears round without ear tufts, but at very close range small ear tufts are visible. In flight, the dark "wrist" on the underwing is the key field mark.

Size: Lengths 33-43cm (13-17")
Wingspan female 107cm (42"), male 105cm (41") (averages)
Weight 206-475g (7-17oz)
Females are slightly larger than Males.

Voice: Short-eared Owls are generally quiet, owing to their diurnal nature and the wide open habitats where visual displays would are more effective than in forests. The male's territorial song is a pulsing "voo-hoo-hoo", resembling an old steam engine. This song is given mainly during flight displays and the female responds with a barking "kee-ow". When excited near the nest, both sexes squawk, bark, hiss and squeal.

Hunting: Short-eared Owls hunt mainly at night and during the morning and late afternoon. They fly over open areas, a few feet above ground, and pounce when prey is located. In dense vegetation they will hover over prey, often for extended periods when facing into the wind, before pouncing. They occasionally hunt from a perch or while standing on the ground. Short-eared Owls eat mainly small mammals, but sometimes take birds. Meadow voles (Microtus species) are the primary prey. Deer mice, shrews, ground squirrels, pocket gophers, pocket mice, moles, rats, bats, rabbits, and muskrats are also taken. Birds probably are more important when Short-eared Owls hunt in marshes and along coastal areas, where they can target shorebirds, terns, and small gulls and seabirds. In inland habitats they take mainly Horned Larks, meadowlarks, blackbirds, and pipits. A few insects such as roaches, grasshoppers, beetles, katydids, and caterpillars are also taken. Unlike most Owls, prey is normally carried in its talons.

Short-eared Owls and Northern Harriers often harass each other when hunting the same field, and harriers often steal food from the Owl. Short-eared Owls mob large day-flying birds like eagles, herons, hawks, Turkey Vultures, and bitterns, seemingly for amusement.

Breeding: Courtship and territorial behaviour is spectacular for an Owl. Males perform aerial displays by rising quickly with rhythmic and exaggerated wing beats, hovering, gliding down, and rising again, often 200 to 400 meters (650 to 1,300 feet) above ground. Wing claps, in bursts of 2 to 6 per second, are often made during this flight and some singing occurs. The flight can be ended with a spectacular descent where the male hold his wings aloft and shimmies rapidly to the ground. Two birds may engage in flight, locking talons, and fighting briefly. Often, a display where one bird flashes its light underwing towards another is used during territorial and courtship flights. The Short-eared Owl nests on the ground, unlike most other Owls. Nests are usually situated in the shelter of a grass mound, under a grass tuft, or among herbaceous ground cover. Nests are loosely constructed by the female, who scrapes a spot on the ground and then lines the scrape with grass stems, herb stalks, and feathers plucked from her breast. Clutch sizes range from 4 to 14 eggs (average 5 to 7), with large clutches laid during years of high food abundance. Clutch size increases from south to north. Eggs are laid every 1 to 2 days and incubation commences with the first. Incubation is done largely by the female, with the male bringing food to the nest and occasionally taking a turn incubating. Young grow very rapidly after hatching, and begin to wander from the nest as soon as 12 days, an adaptation for a ground-nesting species to reduce the amount of time they are vulnerable to predation. Young fledge at about 4 weeks.

The Short-eared Owl routinely lays replacement clutches, because of high predation rates. In southern areas, it may raise 2 broods in 1 year. Because reproductive success is relatively poor, the ability to lay large clutches helps populations recover after periodic declines.

The Short-eared Owl is highly migratory, and nomadic, except in southern parts of its range. Movements of up to 2,000 kilometres (1,200 miles) have been documented. This Owl has relatively small nesting territories and home ranges, varying from 15 to 200 hectares (35 to 500 acres), and may nest in loose colonies in excellent habitat. Because of its nomadic tendencies, mate and site fidelity are very low. Breeders tend to wander until they find areas with high densities of prey before settling to breed. In winter, large numbers of Owls will occur in areas with lots of food. Communal winter roosts of up to 200 birds are known, with these birds ranging over nearby areas to hunt. Resident Owls will defend winter foraging territories of about 6 hectares (15 acres), before expanding the territory size during the breeding season.

Mortality: Wild Short-eared Owls have reached almost 13 years of age. Natural enemies include many diurnal raptors such as the Bald Eagle, Northern Goshawk, Gyrfalcon, Red-tailed Hawk, and Snowy Owl. Because they nest on the ground, they are vulnerable to mammalian predators such as skunks, dogs, foxes, and coyotes, while Jaegers, gulls, ravens, and crows steal eggs and small chicks. Collisions with vehicles account for a large number of deaths. Also, They are attracted to the wide open fields of airports and so many are killed by collisions with aircraft.

Habitat: Short-eared Owls inhabit wide open spaces such as grasslands, prairie, agricultural fields, salt marshes, estuaries, mountain meadows, and alpine and Arctic tundra. Breeding habitat must have sufficient ground cover to conceal nests and nearby sources of small mammals for food. Communal roosts occur in oldgrowth fields, along thick hedgerows, in overgrown rubble in abandoned fields, or in clumps of dense conifers. These Owls tend to roost in trees only when snow covers the ground. During migration, Short-eared Owls will move through high mountain passes, flying at great heights.

Long-eared Owl

Other Names for Long-eared Owls are American Long-eared Owl, Brush Owl, Cat Owl, Pussy Owl, Lesser Horned Owl, Ceder Owl and Coulee Owl.

Description: Long-eared Owls are medium-sized, nocturnal, woodland Owls, with a broad distribution across North America, Eurasia and northern Africa. They appear slim and slouch forward when perched. They have prominent ear tufts that appear to sit in the middle of the head and are u sually held erect. Plumage is brown and buff, with heavy mottling and barring over most of the body. Male plumage tends to be lighter than females. The eyes are golden yellow, encircled by black feathers that are set in an orange-brown facial disk. The bill is black. The forehead and lores are mottled grey and white and there is a white chin patch. The legs and feet are heavily feathered.Juveniles are similar to adults but less heavily marked. The head tufts are shorter and less defined and facial disk darker. Body feathers are tipped with greyish white.

Long-eared Owls are buoyant fliers, appearing to glide noiselessly even when their wings are flapping. They are very maneuverable and can fly through fairly dense brush. They fly moth-like, often hovering and fluttering while looking for prey. When roosting, a Long-eared Owl will stretch its body to make itself appear like a tree branch.

Size: Female average Length: 37cm (14.6")
Wingspan: 100cm (39")
Weight: 282g (10oz)

Male average Length: 34cm (13.4")
Wingspan: 96cm (38")
Weight: 259g (9oz) Voice: The main advertisement call of the male is a low "hoo, hoo, hoo, hoo, .....", repeated 10 to 200 times, with one note very 2 to 3 seconds. The female responds with a raspy buzz call, and often duets with the male. Calling occurs almost always during nocturnal hours. When alarmed, Long-eared Owls bark "whek-WHEK-whek" or shriek like a cat. Both males and females hiss during exchange of prey or when alarmed.

Hunting: Long-eared Owls hunt mainly by ranging over open rangeland, clearings, and fallow fields. They rarely hunt in woodlands where they roost and nest. They hunt mainly from late dusk to just before dawn, flying low to the ground, (1 to 2 meters or 3 to 7 feet), with the head canted to one side listening for prey. When prey is spotted, the Owl pounces immediately, pinning the prey to the ground with its powerful talons. Smaller prey is usually swallowed immediately, or carried away in the bill. Larger prey is carried in the talons.

Long-eared Owls feed primarily on mammals. In most areas voles are the most common prey, but deer mice are the most important prey in other areas. In southwestern deserts, pocket mice and kangaroo rats are primary foods. Other mammal prey includes squirre l s, bats, chipmunks, gophers, shrews, moles, and cottontail rabbits. Birds are rarely taken, and even more rarely taken on the wing. Most bird prey are smaller species that occur on or near the ground. Bird prey includes meadowlarks, blackbirds, juncos, Horned Larks, doves, bluebirds, and thrashers. Larger birds such as grouse and screech-Owls are occasionally taken. These Owls rarely eat insects, frogs, and snakes. Pellets are fairly large, about 5.1 centimeters (2 inches) long and 1.9 centimeters (0.75 inches) thick. Pellets are oval or cylindrical, greyish, and compact with many bones, skulls, and teeth. They are regurgitated 3 to 4 hours after eating.

Breeding: Males occupy nesting territories first and may begin their territorial calling in winter. Nesting occurs mainly from mid March through May in North A merica. During courtship, males perform display flights around nests. Display flights involve erratic gliding and flapping through the trees with occasional single wing claps. Females respond by giving their nest call. The female selects a nest by hopping around it, while the male displays above. She then performs display flights as well, and flies repeatedly to the nest. Leading up to mating, the male approaches the female after calling and performing display flights, then waves his wings as he sidles up to her. Mutual preening and courtship feeding also occur. After pairing, adults roost close together, but the female tends to roost on the nest after it has been selected.

Long-eared Owls nest almost exclusively in old stick nests of crows, magpies, ravens, hawks, or herons. They nest rarely in rock crevices, tree cavities, or on open ground. They have been known to build poorly constructed stick nests, but this is also rare. Nests are almost always located in wooded sites, often screened by shrubbery, vines, or branches and are comm only 5 to 10 meters (16 to 33 feet) above ground.

Long-eared Owls have an impressive nest defense display - the female spreads her wings out widely facing the intruder, flares her flight feathers, and lowers her head. This display makes her appear 2 to 3 times as large as she really is. They also perform a distraction display near nests, where the Owl pretends to capture prey, or feign injury, and flop away from the nest on the ground making various noises. They will occasionally attack viciously, aiming the talons at the face and throat of the intruder.

Old nests are lined with bark strips, feathers, leaves, and moss before eggs are laid. Clutch sizes range from 3 to 8 eggs, with an average of 4 to 5 eggs. Clutch sizes tend to increase from south to north and from east to west. Eggs are laid irregularly every 1 to 5 days and incubation begins with the first egg laid, so that a clutch of 6 eggs may hatch over a period of 10 to 12 days. The female performs most of the incubation but the male may incubate for short intervals while the female hunts. The incubation period is 25 to 30 days. Nestlings begin to walk out of the nest onto nearby branches at about 3 weeks, but are not capable of flight until about 5 weeks. Young become independent from parents at about 2 months. Nesting success is strongly linked to food availability and predation. Long-eared Owls are single-brooded, however, if a cluch is lost, a replacement cluch is laid about three weeks later. Densities of breeding birds are relatively low, except when local food and nesting habitat availability allow loosely colonial nesting.

Mortality: Captive Long-eared Owls have been known to live for over 10 years. Many are killed by shooting and collision with vehicles. Natural enemies of adult birds include Great Horned and Barred Owls. Raccoons are major predators of eggs and nestlings.

Populations fluctuate regularly with prey abundance. Overall populations are thought to be declining in North America because of the loss of riparian nesting habitat through urban and agricultural development. Pesticide use may have secondary effects on Long-eared Owls. Useful habitat enhancements include retention of fallow fields, elimination of vast monocultures, decreased use of pesticides, and planting of conifer groves.

Habitat: Long-eared Owls inhabit open woodlands, forest edges, riparian strips along rivers, hedgerows, juniper thickets, woodlots, and wooded ravines and gulleys. Breeding habitat must include thickly wooded areas for nesting and roosting with nearby open spaces for hunting. During winter, they need dense conifer groves or brushy thickets to roost in. Roosting sites are usually in the heaviest forest cover available. They will also roost in hedgerows, or in caves and cracks in rock canyons.

Unlike most other Owls, during winter they may roost communally (7 to 50 Owls) in dense thickets and range over very large undefended foraging areas. Communal roost sites are often used year after year, probably by the same birds.

Great Grey Owl

The name "nebulosa" is derived from the Latin "Nebulosus", meaning misty or foggy. The Great Grey Owl has also been called Great Grey Ghost, Phantom of the north, Cinerous Owl, Spectral Owl, Lapland Owl, Spruce Owl, Bearded Owl and Sooty Owl.

Description: One of the World's largest Owls, the Great Grey Owl is dark grey overall interspersed with bars and flecks of light grey and white. When perched, they appear very bulky because of their dense, fluffy plumage, long wings extending past the body, a relatively long tail, and a large head. The size of the head, and the prominent facial disk make the yellow eyes appear small. A noticeable white "moustache" strip is under the facial disk, broken by a black "bow-tie". The feet are heavily feathered and remain hidden from view. The Great Grey Owl is a ponderous flier, does not often move more than short distances between perches and seldom glides. They fly close to the ground, usually less than 6 metres (20 feet) up, except when flying to a nest. The Great Grey Owl thermoregulates by roosting in dense cover. When hot, a Great Grey Owl will pant and droop its wings to expose an unfeathered area (apterid) under the wing.

Size: Length 61-84cm (24-33") average 72cm (28") for females, 69cm (27") for males

Wingspan: up to 152cm (60") average 142cm (56") for female, 140cm (55") for males

Weight: 790-1454g (28-51oz) average 1,390g (49oz) for females, 1,290g (45�oz) for males

Voice: The Great Grey Owl has a distinctive primary call which is a very soft, low-pitched hoot "whooo-ooo-ooo-ooo" with the notes emitted slowly over a 6 to 8 second period. Calls are repeated every 15 to 30 seconds. This call is used as a territorial declaration and can be heard up to 800m (� mile) away under good conditions. Territorial calling begins after dusk, peaks before midnight, then peaks again later. Males and females also give a single hoot when near the nest. Females give an excited "ooo-uh" when the male arrives with food. When excited near the nest adults growl, shriek, hoot, wail, and snap their bills. When threatened, a Great Grey Owl will snap its beak, spread its wings, and growl.

Hunting: The Great Grey Owl hunts mainly during early morning and late afternoon, especially during winter, but will also hunt during other daylight hours and at night. They are often seen perched on poles or fenceposts along roads. When hunting, a Great Grey Owl will use a perch to "sit and wait" or it may hunt through the forest a metre or so (a few feet) above the ground. When ground is covered with snow, a Great Grey Owl can hunt by hearing alone and often plunges into the snow to capture small rodents moving underneath as far as 30 centimetres (12 inches). Although a very large Owl, small rodents are their primary prey (80 to 90% of diet) with voles being the most important food in Alaska, Canada, and Oregon. Pocket gophers are the most important food in California. Other mammals taken include rats, mice, shrews, squirrels, rabbits, chipmunks, moles, and weasels. Birds are rarely captured, and include crows, small hawks, American Robin, ducks and grouse. Frogs, toads, snakes, and insects are taken very infrequently. Pellets are very large, about 7� to 10 cm (3-4") long and 2� to 5 cm(1-2") thick. They are dark greyish-black and compact.

Breeding: Courtship involves feeding and mutual preening between mates and begins in midwinter. The male typically approaches the female, holding food in its beak, which is passed with both birds closing their eyes. The male selects possible nest sites and attracts its mate with calls. Several sites are inspected before she chooses the nest site. The Great Grey Owl nests primarily in stick nests made by hawks, ravens, or crows, in the hollowed out top of large-diameter snags, or on the top of clumps of mistletoe, and in Europe sometimes on the forest floor. Northern Goshawks are very common providers of nest sites for Great Grey Owls. They also readily take to artificial platforms or nests placed in suitable habitat. Nests are usually in a forest, but with a large clearing or meadow located within 1.3km (0.8 miles). Unlike most other Owls, nests are usually tidied up and refurbished before use. Nest linings include conifer needles, deer hair, moss, and shredded bark. 2 to 5 (average 3) eggs are laid, each separated by 1 to 2 days. Incubation commences with the first egg laid and lasts 28 to 29 days. The female does all incubation and the male provides all food to the female and young. The female tears food into small pieces and feeds the young. Young leave the nest at 3 to 4 weeks and can climb well. Fledging occurs after about 8 weeks and young remain near the nest for several months, with the female caring for them.

Great Grey Owls are single-brooded but will readily lay replacement clutches if the first clutch or brood is lost. Males and females aggressively defend nests and have been known to drive off predators as large as black bears. Among other threats, ravens and Great Horned Owls prey on eggs and nestlings. The Great Grey Owl is semi-nomadic, with irregular site or mate fidelity between years. They tend to settle and nest in areas with high food resources and this may lead them to occupy the same nest for several years or move off to new areas. Nesting territories are defended from other Great Grey Owls, but foraging areas are widely overlapping. This leads to higher than expected densities, for a large bird of prey. In areas of good habitat this may be as high as 1 pair/58 hectares (5 pairs/square mile).

Mortality: They are long-lived birds, with captive owls living to 40 years of age. Mortality in the wild is often due to starvation. Natural enemies that prey on juveniles are Great Horned Owls, marten, and wolverines. Fatalities caused by humans include shootings, road kills, and electrocutions.

Habitat: The Great Grey Owl inhabits a range of forested habitats. In far north America, they frequent stunted coniferous forests along the edge of the Arctic treeline, through spruce and tamarack muskeg forests further south. In the Sierra Nevada Mountains they breed in mixed conifer and red fir forests. Nesting habitat usually includes copses or islands of aspens within pure stands of conifers. Most foraging is done in open areas such as swamps, bogs, and forest clearings where there are scattered trees and shrubs that can be used as perches. During migration they may be found in estuaries, mountain meadows, and along farm fields.

Owl Links

Information and images for this site gathered from the following places: The Owl Pages

Information on Owls

ORI Identification Guide

Owls

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