Eurasian Eagle-Owl

识别特征

The Eurasian eagle-owl is among the larger birds of prey, smaller than the golden eagle (Aquila chrysaetos), but larger than the snowy owl (Bubo scandiacus), despite some overlap in size with both of those species. It is sometimes referred to as the world's largest owl, although Blakiston's fish owl (B. blakistoni) is slightly heavier on average and the much lighter weight great grey owl (Strix nebulosa) is slightly longer on average. Heimo Mikkola reported the largest specimens of eagle-owl as having the same upper body mass, 4.6 kg (10 lb), as the largest Blakiston’s fish owl and attained a length around 3 cm (1.2 in) longer. In terms of average weight and wing size, the Blakiston’s is the slightly larger species seemingly, even averaging a bit larger in these aspects than the biggest eagle-owl races from Russia. Also, although 9 cm (3.5 in) shorter than the largest of the latter species, the Eurasian eagle-owl can weigh well more than twice as much as the largest great grey owl. The Eurasian eagle-owl typically has a wingspan of 131–188 cm (4 ft 4 in – 6 ft 2 in), with the largest specimens possibly attaining 2 m (6 ft 7 in). The total length of the species can vary from 56 to 75 cm (22 to 30 in). Females can weigh from 1.75 to 4.6 kg (3.9 to 10.1 lb), and males can weigh from 1.2 to 3.2 kg (2.6 to 7.1 lb). In comparison, the barn owl (Tyto alba), the world's most widely distributed owl species, weighs about 0.5 kg (1.1 lb) and the great horned owl (B. virginianus), which fills the eagle-owl's ecological niche in North America, weighs around 1.4 kg (3.1 lb).<p>Besides the female being larger, little external sexual dimorphism is seen in the Eurasian eagle-owl, although the ear tufts of males reportedly tend to be more upright than those of females. When an eagle-owl is seen on its own in the field, distinguishing the individual’s sex is generally not possible. Gender determination by size is possible by in-hand measurements. In some populations, the female typically may be slightly darker than the male. The plumage coloration across at least 13 accepted subspecies can be highly variable. The upper parts may be brown-black to tawny-buff to pale creamy gray, typically showing dense freckling on the forehead and crown, stripes on the nape, sides, and back of the neck, and dark splotches on the pale ground colour of the back, mantle, and scapulars. A narrow buff band, freckled with brown or buff, often runs up from the base of the bill, above the inner part of the eye, and along the inner edge of the black-brown ear tufts. The rump and upper tail-coverts are delicately patterned with dark vermiculations and fine, wavy barring, the extent of which varies with subspecies. The underwing coverts and undertail coverts are similar, but tend to be more strongly barred in brownish-black.<p>The primaries and secondaries are brown with broad, dark brown bars and dark brown tips, and grey or buff irregular lines. A complete moult takes place each year between July and December. The facial disc is tawny-buff, speckled with black-brown, so densely on the outer edge of the disc as to form a "frame" around the face. The chin and throat are white with a brownish central streak. The feathers of the upper breast generally have brownish-black centres and reddish-brown edges except for the central ones, which have white edges. The chin and throat may appear white continuing down the center of the upper breast. The lower breast and belly feathers are creamy-brown to tawny buff to off-white with a variable amount of fine dark wavy barring, on a tawny-buff ground colour. The legs and feet (which are feathered almost to the talons) are likewise marked on a buff ground colour but more faintly. The tail is tawny-buff, mottled dark grey-brown with about six black-brown bars. The bill and feet are black. The iris is most often orange but is fairly variable. In some European birds, the iris is a bright reddish, blood-orange colour but then in subspecies found in arid, desert-like habitats, the iris can range into an orange-yellow colour (most closely related species generally have yellowish irises, excluding the Indian eagle-owl).<p>Among standard measurements for the Eurasian eagle-owl, the wing chord measures 378 to 518 mm (14.9 to 20.4 in), the tail measures 229–310 mm (9.0–12.2 in) long, the tarsus measures 64.5–112 mm (2.54–4.41 in), and the total length of the bill is 38.9–59 mm (1.53–2.32 in). The wings are reportedly the smallest in proportion to the body weight of any European owl, when measured by the weight per area of wing size, was found to be 0.72 g/cm2. Thus, they have quite high wing loading. The great horned owl has even smaller wings (0.8 g/cm2) relative to its body size. The golden eagle has slightly lower wing loading proportionately (0.65 g/cm2), so the aerial abilities of the two species (beyond the eagle’s spectacular ability to stoop) may not be as disparate as expected. Some other owls, such as barn owls, short-eared owls (Asio flammeus), and even the related snowy owls have lower wing loading relative to their size, so are presumably able to fly faster, with more agility, and for more extended periods than the Eurasian eagle-owl. In the relatively small race B. b. hispanus, the middle claw, the largest talon, (as opposed to rear hallux-claw, which is the largest in accipitrids) was found to measure from 21.6 to 40.1 mm (0.85 to 1.58 in) in length. A 3.82 kg (8.4 lb) female examined in Britain (origins unspecified) had a middle claw measuring 57.9 mm (2.28 in), on par in length with a large female golden eagle hallux-claw. Generally, owls do not have talons as proportionately large as those of accipitrids, but have stronger, more robust feet relative to their size. Accipitrids use their talons to inflict organ damage and blood loss, whereas typical owls use their feet to constrict their prey to death, the talons serving only to hold the prey in place or provide incidental damage. The talons of the Eurasian eagle-owl are very large and not often exceeded in size by diurnal raptors. Unlike the great horned owls, the overall foot size and strength of the Eurasian eagle-owl is not known to have been tested, but the considerably smaller horned owl has one of the strongest grips ever measured in a bird.<p>The feathers of the ear tufts in Spanish birds (when not damaged) were found to measure from 63.3 to 86.6 mm (2.49 to 3.41 in). The ear openings (covered in feathers as in all birds) are relatively uncomplicated for an owl, but are also large, being larger on the right than on the left as in most owls, and proportionately larger than those of the great horned owl. In the female, the ear opening averages 31.7 mm (1.25 in) on the right and 27.4 mm (1.08 in) on the left, and in males, averages 26.8 mm (1.06 in) on the right and 24.4 mm (0.96 in) on the left. The depth of the facial disc and the size and complexity of the ear opening are directly correlated to the importance of sound in an owl’s hunting behaviour. Examples of owls with more complicated ear structures and deeper facial disc are barn owls, long-eared owls (Asio otus), and boreal owls (Aegolius funereus). Given the uncomplicated structure of their ear openings and relatively shallow, undefined facial discs, hunting by ear is secondary to hunting by sight in eagle-owls; this seems to be true for Bubo in general. More sound-based hunters such as the aforementioned species likely focus their hunting activity in more complete darkness. Also, owls with white throat patches such as the Eurasian eagle-owl are more likely to be active in low-light conditions in the hours before and after sunrise and sunset rather than the darkest times in the middle of the night. The boreal and barn owls, to extend these examples, lack obvious visual cues such as white throat patches (puffed up in displaying eagle-owls), again indicative of primary activity being in darker periods.<p>The great size, bulky, barrel-shaped build, erect ear tufts, and orange eyes render this as a distinctive species. Other than general morphology, the above features differ markedly from those of two of the next largest subarctic owl species in Europe and western Asia, which are the great grey owl and the greyish to chocolate-brown Ural owl (Strix uralensis), both of which have no ear tufts and have a distinctly rounded head, rather than the blocky shape of the eagle-owl’s head. The snowy owl is obviously distinctive from most eagle-owls, but during winter the palest Eurasian eagle-owl race (B. b. sibiricus) can appear off-white. Nevertheless, the latter is still distinctively an ear-tufted Eurasian eagle-owl and lacks the pure white background colour and variable blackish spotting of the slightly smaller species (which has relatively tiny, vestigial ear tufts that have only been observed to have flared on rare occasions).<p>The long-eared owl has a somewhat similar plumage to the eagle-owl, but is considerably smaller (an average female eagle-owl may be twice as long and 10 times heavier than an average long-eared owl). Long-eared owls in Eurasia have vertical striping like that of the Eurasian eagle-owl, while long-eared owls in North America show a more horizontal striping like that of great horned owls. Whether these are examples of mimicry either way is unclear but it is known that both Bubo owls are serious predators of long-eared owls. The same discrepancy in underside streaking has also been noted in the Eurasian and American representations of the grey owl. A few other related species overlap minimally in range in Asia, mainly in East Asia and the southern reaches of the Eurasian eagle-owl’s range. Three fish owls appear to overlap in range, the brown (Ketupa zeylonensis) in at least northern Pakistan, probably Kashmir, and discontinuously in southern Turkey, the tawny (K. flavipes) through much of eastern China, and Blakiston's fish owl in the Russian Far East, northeastern China, and Hokkaido. Fish owls are distinctively different looking, possessing more scraggy ear tufts that hang to the side rather than sit erect on top of the head, and generally have more uniform, brownish plumages without the contrasting darker streaking of an eagle-owl. The brown fish owl has no feathering on the tarsus or feet, and the tawny has feathering only on the upper portion of the tarsi, but the Blakiston’s is nearly as extensively feathered on the tarsi and feet as the eagle-owl. Tawny and brown fish owls are both slightly smaller than co-occurring Eurasian eagle-owls, and Blakiston’s fish owls are similar or slightly larger than co-occurring large northern eagle-owls. Fish owls, being tied to the edges of fresh water, where they hunt mainly fish and crabs, also have slightly differing, and more narrow, habitat preferences.<p>In the lower Himalayas of northern Pakistan and Jammu and Kashmir, along with the brown fish owl, the Eurasian eagle-owl at the limit of its distribution may co-exist with at least two to three other eagle-owls. One of these, the dusky eagle-owl (B. coromandus) is smaller, with more uniform tan-brownish plumage, untidy uniform light streaking rather than the Eurasian’s dark streaking below and an even less well-defined facial disc. The dusky is usually found in slightly more enclosed woodland areas than Eurasian eagle-owls. Another is possibly the spot-bellied eagle-owl (B. nipalensis), which is strikingly different looking, with stark brown plumage, rather than the warm hues typical of the Eurasian, bold spotting on a whitish background on the belly, and somewhat askew ear tufts that are bold white with light brown crossbars on the front. Both species may occur in some parts of the Himalayan foothills, but they are not currently verified to occur in the same area, in part because of the spot-bellied’s preference for dense, primary forest. Most similar, with basically the same habitat preferences and the only one verified to co-occur with the Eurasian eagle-owls of the race B. b. turcomanus in Kashmir is the Indian eagle-owl (B. bengalensis). The Indian species is smaller, with a bolder, blackish facial disc border, more rounded and relatively smaller wings, and partially unfeathered toes. Far to the west, the pharaoh eagle-owl (B. ascalaphus) also seemingly overlaps in range with the Eurasian, at least in Jordan. Although also relatively similar to the Eurasian eagle-owl, the pharaoh eagle-owl is distinguished by its smaller size, paler, more washed-out plumage, and the diminished size of its ear tufts.<p>The Eurasian eagle-owls’ feathers are lightweight and robust, but nevertheless need to be replaced periodically as they become worn. In the Eurasian eagle-owl, this happens in stages, and the first moult starts the year after hatching with some body feathers and wing coverts being replaced. The next year, the three central secondaries on each wing and three middle tail feathers are shed and regrow, and the following year, two or three primaries and their coverts are lost. In the final year of this postjuvenile moult, the remaining primaries are moulted and all the juvenile feathers will have been replaced. Another moult takes place during years 6-12 of the bird's life. This happens between June and October after the conclusion of the breeding season, and again it is a staged process with six to nine main flight feathers being replaced each year. Such a moulting pattern lasting several years is repeated throughout the bird's life.

分类信息

The Eurasian eagle-owl was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Strix bulbo. Although Linnaeus specified the "habitat" as "Europa" the type locality is restricted to Sweden. The Eurasian eagle-owl is now placed in the genus Bubo that was introduced by André Duméril in 1805.<p>The genus Bubo with 20 extant species includes most of the larger owl species in the world today. Based on an extensive fossil record and a central distribution of extant species on that continent, Bubo appears to have evolved into existence in Africa, although early radiations seem to branch from southern Asia, as well. Two genera belonging to the scops owls complex, the giant scops owls (Otus gurneyi) found in Asia and the Ptilopsis or the white-faced scops owl found in Africa, although firmly ensconced in the scops owl group, appear to share some characteristics with the eagle-owls. The Strix genus is also related to Bubo, and is considered a "sister complex", with Pulsatrix possibly being intermediate between the two. The Eurasian eagle-owl appears to represent an expansion of the genus Bubo into the Eurasian continent. A few of the other species of Bubo seem to have been derived from the Eurasian eagle-owl, making it a "paraspecies", or they at least share a relatively recent common ancestor.<p>The pharaoh eagle-owl, distributed in the Arabian Peninsula and sections of the Sahara Desert through North Africa where rocky outcrops are found, was until recently considered a subspecies of the Eurasian eagle-owl. The pharaoh eagle-owl apparently differs about 3.8% in mitochondrial DNA from the Eurasian eagle-owl, well past the minimum genetic difference to differentiate species of 1.5%. Smaller and paler than Eurasian eagle-owls, the pharaoh eagle-owl can also be considered a distinct species largely due to its higher-pitched and more descending call, and the observation that Eurasian eagle-owls formerly found in Morocco (B. b. hispanus) apparently did not breed with the co-existing pharaoh eagle-owls. On the contrary, the race still found together with the pharaoh eagle-owl in the wild (B. b. interpositus) in the central Middle East has been found to interbreed in the wild with the pharaoh eagle-owl, although genetical materials have indicated B. b. interpositus may itself be a distinct species from the Eurasian eagle-owl, as it differs from the nominate subspecies of the Eurasian eagle-owl by 2.8% in mitochondrial DNA. For three Asian Eurasian eagle-owl subspecies (B. b. ussuriensis, B. b. kiautschensis and B. b. hemachlana, respectively), it was found that they met the criterion for subspecies well, with a high haplotype diversity and in spite of a relatively recent common ancestor and low genetic diversity. The Indian eagle-owl (B. bengalensis) was also considered a subspecies of the Eurasian eagle-owl until recently, but its smaller size, distinct voice (more clipped and high-pitched than the Eurasian), and the fact that it is largely allopatric in distribution (filling out the Indian subcontinent) with other Eurasian eagle-owl races has led to it being considered a distinct species. The mitochondrial DNA of the Indian species also appears considerably distinct from the Eurasian species. The Cape eagle-owl (B. capensis) appears to represent a return of this genetic line back into the African continent, where it leads a lifestyle similar to Eurasian eagle-owls, albeit far to the south. Another offshoot of the northern Bubo group is the snowy owl. It appears to have separated from other Bubo species at least 4 million years ago.<p>The fourth and most famous derivation of the evolutionary line that includes the Eurasian eagle-owl is the great horned owl, which appears to have been the result of primitive eagle-owls spreading into North America. According to some authorities, the great horned owls and Eurasian eagle-owls are barely distinct as species, with a similar level of divergence in their plumages as the Eurasian and North American representations of the great grey owl or the long-eared owl. More outward physical differences exist between the great horned owl and the Eurasian eagle-owl than in those two examples, including a great size difference favoring the Eurasian species, the great horned owl’s horizontal rather than vertical underside barring, yellow rather than orange eyes, and a much stronger black bracket to the facial disc, not to mention a number of differences in their reproductive behaviour and distinctive voices. Furthermore, genetic research has revealed that the snowy owl is more closely related to the great horned owl than are Eurasian eagle-owls. The most closely related species beyond the pharaoh, Indian, and Cape eagle-owls to the Eurasian eagle-owl is the smaller, less powerful and African spotted eagle-owl (B. africanus), which was likely to have divided from the line before they radiated away from Africa. Somehow, genetic materials indicate the spotted eagle-owl appears to share a more recent ancestor with the Indian eagle-owl than with the Eurasian eagle-owl or even the sympatric Cape eagle-owl. Eurasian eagle-owls in captivity have produced apparently healthy hybrids with both the Indian eagle-owl and the great horned owl. The pharaoh, Indian, and Cape eagle-owls and the great horned owl are all broadly similar in size to each other, but all are considerably smaller than the Eurasian eagle-owl, which averages at least 15–30% larger in linear dimensions and 30–50% larger in body mass than these other related species, possibly as the eagle-owls adapted to warmer climates and smaller prey. Fossils from southern France have indicated that during the Middle Pleistocene, Eurasian eagle-owls (this paleosubspecies is given the name B. b. davidi) were larger than they are today, even larger were those found in Azerbaijan and in the Caucasus (either B. b. bignadensis or B. bignadensis), which were deemed to date to the Late Pleistocene. About 12 subspecies are recognized today.

学名

Bubo bubo

命名信息

(Linnaeus, 1758)

目

Strigiformes

科

Strigidae

属

Bubo

分布与栖息地

The Eurasian eagle-owl is one of the most widely distributed of all owl species, although it is far less wide-ranging than the barn owl, the short-eared owl (Asio flammeus) and long-eared owl and lacks the circumpolar range of boreal species such as great grey owl, boreal owl and northern hawk owl (Surnia ulula). This eagle-owl reaches its westernmost range in the Iberian Peninsula, both almost throughout Spain and more spottily in Portugal. From there, the Eurasian eagle-owl ranges widely in the south of France from Toulouse to Monaco and as far north into the central part of the country as in Allier. Farther north, they are found sporadically and discontinuously in Luxembourg, southern and western Belgium and scarcely into the Netherlands. It is infrequently found in southern and central United Kingdom. In Germany, the eagle-owl can be found in large but highly discontinuous areas, mostly in the south and central areas but is almost entirely absent in areas such as Brandenburg. Across from its south German range, this species range is nearly continuous into the Czech Republic, Slovakia, northern and eastern Hungary and very spottily into Poland. In the fairly montane countries of Switzerland and Austria, the eagle-owl can be found fairly broadly. In Italy, the Eurasian eagle-owl is found where the habitat is favorable in much of the northern, western and central portions down to as far south Melito di Porto Salvo. From Italy, this species sweeps quite broadly along the Mediterranean coast in Southeastern Europe from Slovenia mostly continuously to most of Greece and Bulgaria. In eastern Europe, the Eurasian eagle-owl is found essentially throughout from central Romania to Estonia. The species also occupies a majority of Finland and Scandinavia, where most broadly found in Norway, somewhat more spottily in Sweden and in Denmark it is found widely in Jutland (absent from the islands).<p>The Eurasian eagle-owl's range in Russia is truly massive, with the species apparently nearly unbound by habitat, with their distribution only excluding them from the true Arctic zone, i.e. their range stops around the tree line. If not the most densely populated species, they almost certainly stand as Russia's most widely distributed owl species. From Russia, they are found throughout Central Asia, residing continuously in each nation from Kazakhstan down to Afghanistan. In Asia Minor, they are found broadly in Georgia, Azerbaijan and somewhat so in western and southern Turkey but is quite sporadic in distribution overall in Turkey. A spotty range also exists in the Middle East in Syria, Iraq, Lebanon, Israel, Jordan and western Iran, the species being found broadly only in north and western Iran. In South Asia, the Eurasian eagle-owl is found mostly often in northern Pakistan, northern Nepal and Bhutan and more marginally into far northern India. This species resides throughout Mongolia, almost the entirety of China (mainly absent only from southern Yunnan and southern Guangxi). From China and eastern Russia, the Eurasian eagle-owl is found throughout Korea, Sakhalin, the Kuril Islands and rarely into Japan in northern Hokkaido. Besides the Kurils, the farthest eastern part of the range for this species is in Magadan in the Russian Far East. Eagle-owls are distributed somewhat sparsely, but can potentially inhabit a wide range of habitats, with a partiality for irregular topography. They have been found in habitats as diverse as northern coniferous forests to the edge of vast deserts. Essentially, Eurasian eagle-owls have been found living in almost every climatic and environmental condition on the Eurasian continent, excluding the greatest extremities, i.e. they are absent from humid rainforest in Southeast Asia, and the high Arctic tundra, both of which they are more or less replaced by other species of Bubo owls. They are often found in the largest numbers in areas where cliffs and ravines are surrounded by a scattering of trees and bushes. Grassland areas such as alpine meadows or desert-like steppe can also host them so long as they have the cover and protection of rocky areas. The preference of eagle-owls for places with irregular topography has been reported in most known studies. The obvious benefit of such nesting locations is that both nests and daytime roosts located in rocky areas and/or steep slopes would be less accessible to predators, including man. Also, they may be attracted to the vicinity of riparian or wetlands areas, because the soft soil of wet areas is conducive to burrowing by the small, terrestrial mammals normally preferred in the diet, such as voles and rabbits.<p>Due to their preference for rocky areas, the species is often found in mountainous areas, and can be found up to elevations of 2,100 m (6,900 ft) in the Alps, 4,500 m (14,800 ft) in the Himalayas, and 4,700 m (15,400 ft) in the adjacent Tibetan Plateau. They can also be found living at sea level and may nest amongst rocky sea cliffs. Despite their success in areas such as subarctic zones and mountains that are frigid for much of the year, warmer conditions seem to result in more successful breeding attempts per studies in the Eifel region of Germany. In a study from Spain, areas primarily consisting of woodlands (52% of study area being forested) were preferred with pine trees predominating the oaks in habitats used, as opposed to truly mixed pine-oak woodland. Pine and other coniferous stands are often preferred in great horned owls, as well, due to the constant density, which make overlooking the large birds more likely. In mountainous forest, they are not generally found in enclosed wooded areas, as is the tawny owl (Strix alucco), instead usually near forest edge. Only 2.7% of the habitat included in the territorial ranges for eagle-owls per the habitat study in Spain consisted of cultivated or agricultural land. Compared to golden eagles, though, they can visit cultivated land more regularly in hunting forays due to their nocturnal habits, which allow them to largely evade human activity. Other accounts make clear that farmland is only frequented where its less intensively farmed, holds more extensive treed and bushy areas, and often has limited to no irrigation; farmland areas with fallow or abandoned fields are more likely to holdmore prey, so are prone to less frequent human disturbance. In the Italian Alps, almost no pristine habitat remained, and eagle-owls nested locally in the vicinity of towns, villages, and ski resorts.<p>Although found in the largest numbers in areas sparsely populated by humans, farmland is sometimes inhabited, and they even have been observed living in park-like or other quiet settings within European cities. Since 2005, at least five pairs have nested in Helsinki. This is due in part to feral European rabbits (Oryctolagus cuniculus) having recently populated the Helsinki area, originally from pet rabbits released to the wild. The number is expected to increase due to the growth of the European rabbit population in Helsinki. European hares (Lepus europaeus), the often preferred prey species by biomass of the eagle-owls in their natural habitat, live only in rural areas of Finland, not in the city centre. In June 2007, an eagle-owl nicknamed 'Bubi' landed in the crowded Helsinki Olympic Stadium during the European Football Championship qualification match between Finland and Belgium. The match was interrupted for six minutes. After tiring of the match, following Jonathan Johansson's opening goal for Finland, the bird left the scene. Finland's national football team have had the nickname Huuhkajat (Finnish for "Eurasian eagle-owls") ever since. The owl was named "Helsinki Citizen of the Year" in December 2007. In 2020, a brood of three eagle-owl chicks was raised by their mother on a large, well-foliaged planter on an apartment window in the city centre of Geel, Belgium.

迁徙

Resident species

行为

The Eurasian eagle-owl is largely nocturnal in activity, as are most owl species, with its activity focused in the first few hours after sunset and the last few hours before sunrise. In the northern stretches of its range, partial diurnal behaviour has been recorded, including active hunting in broad daylight during the late afternoon. In such areas, full nightfall is essentially non-existent at the peak of summer, so eagle-owls must presumably hunt and actively brood at the nest during daylight. The Eurasian eagle-owl has a number of vocalizations that are used at different times. It will usually select obvious topographic features such as rocky pinnacles, stark ridges and mountain peaks to use as regular song posts. These are dotted along the outer edges of the eagle-owl's territory and they are visited often but only for a few minutes at a time.<p>Vocal activity is almost entirely confined to the colder months from late fall through winter, with vocal activity in October through December mainly having territorial purposes and from January to February being primarily oriented towards courtship and mating purposes. Vocalizations in a Spanish study begin no sooner than 29 minutes after sunset and end no later than 55 minutes before sunrise. The territorial song, which can be heard at great distance, is a deep resonant ooh-hu with emphasis on the first syllable for the male, and a more high-pitched and slightly more drawn-out uh-hu for the female. It is not uncommon for a pair to perform an antiphonal duet. The widely used name in Germany as well as some other sections of Europe for this species is uhu due to its song. At 250–350 Hz, the Eurasian eagle-owls territorial song or call is deeper, farther-carrying and is often considering "more impressive" than the territorial songs of the great horned owl or even that of the slightly larger Blakiston's fish owl, although the horned owl’s call averages slightly longer in duration and the Blakiston's call is typically deeper. Other calls include a rather faint, laughter-like OO-OO-oo and a harsh kveck-kveck. Intruding eagle-owls and other potential dangers may be met with a "terrifying", extremely loud hooo. Raucous barks not unlike those of ural owls or long-eared owls have been recorded but are deeper and more powerful than those species’ barks. Annoyance at close quarters is expressed by bill-clicking and cat-like spitting, and a defensive posture involves lowering the head, ruffling the back feathers, fanning the tail and spreading the wings.<p>The Eurasian eagle-owl rarely assumes the so-called "tall-thin position", which is when an owl adopts an upright stance with plumage closely compressed and may stand tightly beside a tree trunk. Among others, the long-eared owl is among the most often reported to sit with this pose. The great horned owl has been more regularly recorded using the tall-thin, if not as consistently as some Strix and Asio owls, and it is commonly thought to aid camouflage if encountering a threatening or novel animal or sound. The Eurasian eagle-owl is a broad-winged species and engages in a strong, direct flight, usually consisting of shallow wing beats and long, surprisingly fast glides. It has, unusually for an owl, also been known to soar on updrafts on rare occasions. The latter method of flight has led them to be mistaken for Buteos, which are smaller and quite differently proportioned. Usually when seen flying during the day, it is due to being disturbed or displaced from its roost by humans or mobbing animals, such as crows. Eurasian eagle-owls are highly sedentary, normally maintaining a single territory throughout their adult lives.<p>Eurasian eagle-owl are considered a completely non-migratory bird, as are all members of the Bubo genus excluding the snowy owl. Even those near the northern limits of their range, where winters are harsh and likely to bear little in food, the eagle-owl does not leave its native range. In 2020, a study presented evidence of a short distance distribution by adult eagle-owls in the fall subsequent to breeding, with 5 adults found to move over 20 km (12 mi) away from their nests. There are additionally claimed cases from Russia of Eurasian eagle-owls moving south for the winter, as the icebound, infamously harsh climate there may be too severe even for these hardy birds and their prey. Similarly, Eurasian eagle-owls living in the Tibetan highlands and Himalayas may in some anecdotal cases vacate their normal territories when winter hits and move south. In both of those examples, these are old, unverified reports and there is no evidence whatsoever of consistent, annual migration by Eurasian eagle-owls and the birds may eke out a living on their normal territories even in the sparsest times.

保护状况

种群趋势

declining