174-489: An owlet is a young owl. Owlet may also refer to: Owl Strigidae Tytonidae Ogygoptyngidae ( fossil ) Palaeoglaucidae ( fossil ) Protostrigidae ( fossil ) Sophiornithidae ( fossil ) Strigidae sensu Sibley & Ahlquist Owls are birds from the order Strigiformes ( / ˈ s t r ɪ dʒ ə f ɔːr m iː z / ), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance,
348-425: 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. The Eurasian eagle-owl rarely assumes
522-405: A day or two apart. Like all owls that nest in the open, the downy young are often a mottled grey with some white and buff, which provides camouflage. They open their eyes at 4 days of age. The chicks grow rapidly, being able to consume small prey whole after roughly 3 weeks. In Andalusia , the most noticeable development of the young before they leave the nest was the increase of body size, which
696-461: 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
870-399: A facial ruff, which creates an anterior-facing, concave wall that cups the sound into the ear structure. This facial ruff is poorly defined in some species, and prominent, nearly encircling the face, in other species. The facial disk also acts to direct sound into the ears, and a downward-facing, sharply triangular beak minimizes sound reflection away from the face. The shape of the facial disk
1044-453: A few centimetres of their eyes. Caught prey can be felt by owls with the use of filoplumes —hairlike feathers on the beak and feet that act as "feelers". Their far vision, particularly in low light, is exceptionally good. Owls can rotate their heads and necks as much as 270°. Owls have 14 neck vertebrae — humans have only seven — and their vertebral circulatory systems are adapted to allow them to rotate their heads without cutting off blood to
1218-503: A few species specialize in hunting fish . They are found in all regions of the Earth except the polar ice caps and some remote islands. A group of owls is called a "parliament". Owls possess large, forward-facing eyes and ear-holes, a hawk -like beak , a flat face, and usually a conspicuous circle of feathers, a facial disc , around each eye. The feathers making up this disc can be adjusted to sharply focus sounds from varying distances onto
1392-402: A large, broad head, binocular vision , binaural hearing , sharp talons , and feathers adapted for silent flight. Exceptions include the diurnal northern hawk-owl and the gregarious burrowing owl . Owls are divided into two families : the true (or typical) owl family, Strigidae, and the barn owl family, Tytonidae. Owls hunt mostly small mammals , insects , and other birds, although
1566-621: A male's sexual advances, smaller male owls that have the ability to escape unreceptive females are more likely to have been selected. If the character is stable, there can be different optimums for both sexes. Selection operates on both sexes at the same time; therefore it is necessary to explain not only why one of the sexes is relatively bigger, but also why the other sex is smaller. If owls are still evolving toward smaller bodies and longer wing chords, according to V. Geodakyan's Evolutionary Theory of Sex, males should be more advanced on these characters. Males are viewed as an evolutionary vanguard of
1740-442: A mean of about 1.2 to 1.7 despite evidence that increased human activity near the nest decreased owlet survivability. While sibling owls are close in the stage between leaving the nest and fully fledged, about 20 days after leaving the nest, the family unit seems to dissolve and the young disperse quickly and directly. All told, the dependence of young eagle-owls on their parents lasts for 20 to 24 weeks. Independence in central Europe
1914-530: A person climbs to an active nest, the adult female eagle-owl will do a distraction display , in which they feign an injury. This is an uncommon behavior in most owls and is most often associated with small birds trying to falsely draw the attention of potential predators away from their offspring. More commonly, the adults withdraw to a safe distance, as their nests are usually well-camouflaged. Occasionally if cornered both adults and nestlings will do an elaborate threat display, also rare in owls in general, in which
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#17328699528682088-558: A population, and sexual dimorphism on the character, as an evolutionary "distance" between the sexes. "Phylogenetic rule of sexual dimorphism" states that if there exists a sexual dimorphism on any character, then the evolution of this trait goes from the female form toward the male one. All owls are carnivorous birds of prey and live on diets of insects, small rodents and lagomorphs. Some owls are also specifically adapted to hunt fish. They are very adept in hunting in their respective environments. Since owls can be found in nearly all parts of
2262-527: A relatively small skull is that the eye of the owl has become tubular in shape. This shape is found in other so-called nocturnal eyes, such as the eyes of strepsirrhine primates and bathypelagic fishes . Since the eyes are fixed into these sclerotic tubes, they are unable to move the eyes in any direction. Instead of moving their eyes, owls swivel their heads to view their surroundings. Owls' heads are capable of swiveling through an angle of roughly 270°, easily enabling them to see behind them without relocating
2436-526: A series of reintroductions. Conversely to numerous threats and declines incurred by Eurasian eagle-owls, areas where human-dependent, non-native prey species such as brown rats ( Rattus norvegicus ) and rock doves ( Columba livia ) have flourished, have given the eagle-owls a primary food source and allowed them occupy regions where they were once marginalized or absent. The Eurasian eagle-owl at one time occurred naturally in Great Britain. Some, including
2610-407: A serious cause of mortality locally. Eagle-owls have been singled out historically as a threat to game species, thus to the economic well-being of landowners, game-keepers, and even governmental agencies, and as such, have been singled out for widespread persecution. Local extinctions of Eurasian eagle-owls have been primarily due to persecution. Examples of this include northern Germany in 1830,
2784-573: 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
2958-413: A strong advantage over prey alert to the slightest sound in the night. A silent, slow flight is not as necessary for diurnal and crepuscular owls given that prey can usually see an owl approaching. Owls' feathers are generally larger than the average birds' feathers, have fewer radiates, longer pennulum, and achieve smooth edges with different rachis structures. Serrated edges along the owl's remiges bring
3132-608: 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
3306-491: A third adult of undetermined sex helping a breeding pair care for the chicks. The response of Eurasian eagle-owls to humans approaching at the nest is quite variable. The species is often rather less aggressive than some other owls, including related species like the spot-bellied eagle-, great horned and snowy owls, many of the northern Strix species, and even some rather smaller owl species, which often fearlessly attack any person found to be nearing their nests. Occasionally, if
3480-450: 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
3654-592: A total population estimated to be between 100,000 and 500,000 individuals, the IUCN lists the bird's conservation status as being of least concern , although the trend is listed as decreasing. The vast majority of eagle-owls live in Continental Europe , Scandinavia , Russia (which is almost certainly where the peak numbers and diversity of race occurs), and Central Asia . Additional minor populations exist in Anatolia ,
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#17328699528683828-496: 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,
4002-652: A variably hued buff, streaked with darker colouring. The facial disc is not very defined. The orange eyes are distinctive. At least 12 subspecies of the Eurasian eagle-owl are described. Eurasian eagle-owls are found in many habitats; mostly mountainous and rocky areas, often near varied woodland edge and near shrubby areas with openings or wetlands . They also inhabit coniferous forests , steppes , and remote areas. Occasionally, they are found in farmland and in park -like settings in European and Asian cities and, very rarely, in busier urban areas. The eagle-owl
4176-521: A very different way (such as the terrestrial Sophiornithidae ). The Paleocene genera Berruornis and Ogygoptynx show that owls were already present as a distinct lineage some 60–57 million years ago (Mya), hence, possibly also some 5 million years earlier, at the extinction of the non-avian dinosaurs . This makes them one of the oldest known groups of non- Galloanserae landbirds. The supposed " Cretaceous owls" Bradycneme and Heptasteornis are apparently non- avialan maniraptors . During
4350-399: A very wide range across much of Europe and Asia, estimated to be about 32,000,000 km (12,000,000 sq mi). In Europe, the population is estimated at 19,000 to 38,000 breeding pairs, and in the whole world around 250,000 to 2,500,000 individual birds. The population trend is thought to be decreasing because of human activities, but with such a large range and large total population,
4524-450: 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
4698-414: Is a physical difference between males and females of a species. Female owls are typically larger than the males. The degree of size dimorphism varies across multiple populations and species, and is measured through various traits, such as wing span and body mass. One theory suggests that selection has led males to be smaller because it allows them to be efficient foragers . The ability to obtain more food
4872-463: Is a subject of controversy. Those eagle-owls reintroduced in the Eifel region appear to be able to breed successfully, and enjoy nesting success comparable with wild eagle-owls from elsewhere in Europe. Mortality levels in the Eifel region, though, appear to remain quite high due to anthropogenic factors. Also, concerns exist about a lack of genetic diversity of the species in this part of Germany. Apparently,
5046-446: Is able to determine the direction from which the sound is coming by the minute difference in time that it takes for the sound waves to penetrate the left and right ears. The owl turns its head until the sound reaches both ears at the same time, at which point it is directly facing the source of the sound. This time difference between ears is about 30 microseconds. Behind the ear openings are modified, dense feathers, densely packed to form
5220-399: Is adjustable at will to focus sounds more effectively. The prominences above a great horned owl's head are commonly mistaken as its ears. This is not the case; they are merely feather tufts. The ears are on the sides of the head in the usual location (in two different locations as described above). While the auditory and visual capabilities of the owl allow it to locate and pursue its prey,
5394-495: Is advantageous during breeding season. In some species, female owls stay at their nest with their eggs while it is the responsibility of the male to bring back food to the nest. If food is scarce, the male first feeds himself before feeding the female. Small birds, which are agile, are an important source of food for owls. Male burrowing owls have been observed to have longer wing chords than females, despite being smaller than females. Furthermore, owls have been observed to be roughly
Owlet - Misplaced Pages Continue
5568-494: 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,
5742-403: 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 )
5916-526: Is anytime hereafter; i.e. the period between the beginning of juvenile dispersal to egg laying; from September to early January. The same general date parameters were followed in southern France. In the Italian Alps, the mean egg-laying date was similarly February 27, but the young were more likely to be dependent later, as all fledglings were still being cared for by the end of August, and some even lingered under parental care until October. In northern climes,
6090-500: 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
6264-484: 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
6438-657: Is from September to November. The young leave their parents' care normally on their own, but are also sometimes chased away by their parents. The young Eurasian eagle-owls reach sexual maturity by the following year, but do not normally breed until they can establish a territory at around 2–3 years old. Until they are able to establish their own territories, young eagle-owls spend their lives as nomadic "floaters", and while they also call, select inconspicuous perch sites unlike breeding birds. Male floaters are especially wary about intrusion into an established territory to avoid potential conspecific aggression. The Eurasian eagle-owl has
6612-453: 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
6786-506: Is mostly a nocturnal predator . Predominantly, they hunt small mammals , such as rodents and rabbits , but also birds and larger mammals. Secondary prey include reptiles , amphibians , fish , large insects , and invertebrates . The species typically breeds on cliff ledges, in gullies , among rocks, and in other concealed locations. The nest is a scrape containing a clutch of 2–4 eggs typically, which are laid at intervals and hatch at different times. The female incubates
6960-513: 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
7134-468: 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). The long-eared owl has
Owlet - Misplaced Pages Continue
7308-423: Is often just called the eagle-owl in Europe and Asia. It is one of the largest species of owl . Females can grow to a total length of 75 cm (30 in), with a wingspan of 188 centimetres (6 feet 2 inches). Males are slightly smaller. This bird has distinctive ear tufts , with upper parts that are mottled with darker blackish colouring and tawny. The wings and tail are barred. The underparts are
7482-580: Is perhaps the most serious factor to be addressed in Spain, persecution continues to be a massive problem for Spanish eagle-owls. Of seven European nations where modern Eurasian eagle-owl mortality is well-studied, continual persecution is by far the largest problem in Spain, although also continues to be serious (often comprising at least half of studied mortality) in France. From France and Spain, nearly equal numbers of eagle-owls are poisoned (for which raptors might not be
7656-495: Is present, they will nest on the ground between rocks. Often, in more densely forested areas, they've been recorded nesting on the ground, often among roots of trees, under large bushes and under fallen tree trunks. Steep slopes with dense vegetation are preferred if nesting on the ground, although some ground nests are surprisingly exposed or in flat spots such as in open spots of the taiga , steppe , ledges of river banks and between wide tree trunks. All Eurasian eagle-owl nests in
7830-615: Is quite sporadic in distribution overall in Turkey. A spotty range also exists in the Middle East in Syria , Iraq , Lebanon , Israel , Palestine , 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
8004-411: Is similar or occasionally slightly greater than great horned owl: averaging 15 to 80 km (5.8 to 30.9 sq mi). Territories are established by the male eagle-owl, who selected the highest points in the territory from which to sing. The high prominence of singing perches allows their song to be heard at greater distances and lessens the need for potentially dangerous physical confrontations in
8178-456: 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
8352-467: 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
8526-500: 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
8700-513: Is the more common number. In at least one species, female owls do not mate with the same male for a lifetime. Female burrowing owls commonly travel and find other mates, while the male stays in his territory and mates with other females. Recent phylogenetic studies place owls within the clade Telluraves , most closely related to the Accipitrimorphae and the Coraciimorphae , although
8874-508: 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,
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#17328699528689048-427: Is used to tear the tissue and kill. The sharp lower edge of the upper bill works in coordination with the sharp upper edge of the lower bill to deliver this motion. The downward-facing beak allows the owl's field of vision to be clear, as well as directing sound into the ears without deflecting sound waves away from the face. The coloration of the owl's plumage plays a key role in its ability to sit still and blend into
9222-643: The Caucasus (either B. b. bignadensis or B. bignadensis ), which were deemed to date to the Late Pleistocene . About 12 subspecies are recognized today. 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
9396-666: The International Union for Conservation of Nature has rated the bird as being of least concern . Although roughly equal in adaptability and wideness of distribution, the great horned owl, with a total estimated population up to 5.3 million individuals, apparently has a total population that is roughly twice that of the Eurasian eagle-owl. Numerous factors, including a shorter history of systematic persecution, lesser sensitivity to human disturbance while nesting, somewhat greater ability to adapt to marginal habitats and widespread urbanization, and slightly smaller territories may play into
9570-597: The Paleogene , the Strigiformes radiated into ecological niches now mostly filled by other groups of birds. The owls as known today, though, evolved their characteristic morphology and adaptations during that time, too. By the early Neogene , the other lineages had been displaced by other bird orders, leaving only barn owls and typical owls. The latter at that time was usually a fairly generic type of (probably earless) owl similar to today's North American spotted owl or
9744-582: The RSPB , have claimed that it had disappeared about 10,000–9,000 years ago, after the last ice age , but fossil remains found in Meare Lake Village indicate the eagle-owl occurring as recently as roughly 2,000 years ago in the fossil record. The lack of presence of the Eurasian eagle-owl in British folklore or writings in recent millennium may indicate the lack of occurrence by this species there. The flooding of
9918-431: 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/cm . Thus, they have quite high wing loading . The great horned owl has even smaller wings (0.8 g/cm ) relative to its body size. The golden eagle has slightly lower wing loading proportionately (0.65 g/cm ), so
10092-648: 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. 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
10266-467: 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
10440-545: The massifs of France, and 1.82 to 1.89 in central Europe and the eastern Alps ; in Sweden and Finland, the mean clutch size is 1.56 and 1.87, respectively. While variation based on climate is not unusual for different wide-ranging palearctic species, the higher clutch size of western Mediterranean eagle-owls is also probably driven by the presence of lagomorphs in the diet, which provide high nutritional value than most other regular prey. The average clutch size, attributed as 2.7,
10614-412: 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
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#173286995286810788-518: 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
10962-656: The uropygial gland , informally the "preen" or "oil" gland, as most birds do, to spread oils across their plumage through preening. This makes them highly vulnerable to heavy rain when they are unable to hunt. Historically, they would switch to hunting indoors in wet weather, using barns and other agricultural buildings, but the decline in the numbers of these structures in the 20th and 21st centuries has reduced such opportunities. The lack of waterproofing means that barn owls are also susceptible to drowning, in drinking troughs and other structures with smooth sides. The Barn Owl Trust provides advice on how this can be mitigated, by
11136-525: 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
11310-400: 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 )
11484-574: 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
11658-472: 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. The fourth and most famous derivation of
11832-471: 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. 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
12006-498: The European tawny owl ; the diversity in size and ecology found in typical owls today developed only subsequently. Around the Paleogene-Neogene boundary (some 25 Mya), barn owls were the dominant group of owls in southern Europe and adjacent Asia at least; the distribution of fossil and present-day owl lineages indicates that their decline is contemporary with the evolution of the different major lineages of true owls, which for
12180-571: The German reintroductions have allowed eagle-owls to repopulate neighbouring parts of Europe, as the breeding populations now occurring in the Low Countries (the Netherlands, Belgium, and Luxembourg) are believed to be the result of influx from regions further to the east. Smaller reintroductions have been done elsewhere, and the current breeding population in Sweden is believed to be primarily the result of
12354-475: The Italian Alps, almost no pristine habitat remained, and eagle-owls nested locally in the vicinity of towns , villages , and ski resorts . 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
12528-748: 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
12702-508: The Netherlands sometimes in the late 19th century, Luxembourg in 1903, Belgium in 1943, and central and western Germany in the 1960s. In trying to determine causes of death for 1476 eagle-owls from Spain, most were unknown and undetermined types of trauma. The largest group that could be determined, 411 birds, was due to collisions, more than half of which were from electrocution, while 313 were due to persecution, and merely 85 were directly attributable to natural causes. Clearly, while pylon safety
12876-717: The Swiss Rhine Valley was variable, in radio-tagged, released individuals, most died as a result of starvation (48%) rather than human-based causes, but 93% of the wild, untagged individuals found dead were due to human activities, 46% due to electrocution, and 43% due to collision with vehicles or trains. Insulation of pylons is thought to result in a stabilisation of the local population due to floaters taking up residence in unoccupied territories that formerly held deceased eagle-owls. Eurasian eagle-owls from Finland were found mainly to die due to electrocution (39%) and collisions with vehicles (22%). Wind turbine collisions can also be
13050-629: 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. Eurasian eagle-owls are strictly territorial and will defend their territories from interloping eagle-owls year around, but territorial calling appears to peak around October to February. Territory size
13224-536: 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
13398-400: 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
13572-514: The areas where territories may meet. Nearly as important in territorial behaviour as vocalization is the white throat patch. When taxidermied specimens with flared white throats were placed around the perimeter of eagle-owl territories, male eagle-owls reacted quite strongly and often attacked the stuffed owl, reacting more mildly to a stuffed eagle-owl with a non-flared white throat. Females were less likely to be aggressive to mounted specimens and did not seem to vary in their response whether exposed to
13746-588: 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. 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
13920-443: 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
14094-489: 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. The Eurasian eagle-owl was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under
14268-591: The birds to the risk of collisions with deadly man-made objects (e.g. pylons) and a depletion of native prey numbers due to ongoing habitat degradation and urbanisation. In Spain, long-term governmental protection of the Eurasian eagle-owl seems to have no positive effect on reducing the persecution of eagle-owls. Therefore, Spanish conservationists have recommended to boost education and stewardship programs to protect eagle-owls from direct killing by local residents. Unanimously, biologists studying eagle-owl mortality and conservation factors have recommended to proceed with
14442-409: The brain . Specifically, the foramina in their vertebrae through which the vertebral arteries pass are about 10 times the diameter of the artery, instead of about the same size as the artery, as is the case in humans; the vertebral arteries enter the cervical vertebrae higher than in other birds, giving the vessels some slack, and the carotid arteries unite in a very large anastomosis or junction,
14616-434: The breeding season shifts somewhat later by as much as a month so that egg laying may be as late as late March or early April. Nonetheless, the Eurasian eagle-owl is one of the earliest nesting bird species in Europe or northern, temperate Asia. The first egg hatches after 31 to 36 days of incubation. The eggs hatch successively; although the average interval between egg-laying is 3 days, the young tend to hatch no more than
14790-508: 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
14964-552: 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
15138-418: 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
15312-835: The contrary, no evidence of any organization or individual intentionally releasing eagle-owls recently with the intent to establish a breeding population has been found. Many feel that the eagle-owl would be classified as an "alien" species. Due to its predatory abilities, many, especially those in the press, have expressed alarm of their effect on "native" species. From 1994 to 2007, 73 escaped eagle-owls were not registered as returned, while 50 escapees were recaptured. Several recorded breeding attempts have been studied, and most were unsuccessful, due in large part to incidental disturbance by humans and some due to direct persecution, with eggs having been smashed. As highly opportunistic predators, Eurasian eagle-owls hunt almost any appropriately sized prey they encounter. Most often, they take whatever prey
15486-632: 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
15660-416: 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
15834-522: 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. 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,
16008-450: The deciduous woodland it prefers for its habitat. Likewise, the mottled wood owl ( Strix ocellata ) displays shades of brown, tan, and black, making the owl nearly invisible in the surrounding trees, especially from behind. Usually, the only tell-tale sign of a perched owl is its vocalizations or its vividly colored eyes. Most owls are nocturnal , actively hunting their prey in darkness. Several types of owls are crepuscular —active during
16182-506: 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
16356-401: The eagle-owl is too large to utilize tree hollows, when other large species like the great grey owl have never been recorded nesting in one, the even more robust Blakiston's fish owl nests exclusively in cavernous hollows. The Eurasian eagle-owl often uses the same nest site year after year. In Engadin , Switzerland, the male eagle-owl alone hunts until the young are 4 to 5 weeks old and
16530-406: The eagle-owl was deemed extinct in the country as a breeding species by the 1960s, as a result of a long period of heavy persecution. The largest reintroduction there occurred from the 1970s to the 1990s in the Eifel region, near the border with Belgium and Luxembourg. The success of this measure, consisting in more than a thousand eagle-owls being reintroduced at an average cost of US$ 1,500 per bird,
16704-585: The eagle-owls of the fairly heavily wooded wildlands of Belarus , they more commonly utilize nests built by other birds than most eagle-owls, i.e. stork or accipitrid nests, but a majority of nests are still located on the ground. This is contrary to the indication that ground nests are selected only if rocky areas or other bird nests are unavailable, as many will utilize ground nests even where large bird nests seem to be accessible. Tree holes being used for nesting sites are even more rarely recorded than nests constructed by other birds. While it may be assumed that
16878-565: The eagle-owls raise their wings into a semi-circle and puff up their feathers, followed by a snapping of their bills. Apparently, eagle-owls of uncertain and probably exotic origin in Britain are likely to react aggressively to humans approaching the nest. Also, aggressive encounters involving eagle-owls around their nest, despite being historically uncommon, apparently have increased in recent decades in Scandinavia. The discrepancy of aggressiveness at
17052-482: 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
17226-405: The edges of fresh water, where they hunt mainly fish and crabs, also have slightly differing, and more narrow, habitat preferences. 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 )
17400-419: The eggs and broods the young. The male brings food for her and for the nestlings. Continuing parental care for the young is provided by both adults for about five months. In addition to being one of the largest living species of owl, the Eurasian eagle-owl is also one of the most widely distributed. With a total range in Europe and Asia of about 51.4 million km (19.8 million sq mi) and
17574-553: 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 . The Eurasian eagle-owl
17748-423: The environment, making it nearly invisible to prey. Owls tend to mimic the coloration and sometimes the texture patterns of their surroundings, the barn owl being an exception. The snowy owl ( Bubo scandiacus ) appears nearly bleach-white in color with a few flecks of black, mimicking their snowy surroundings perfectly, while the speckled brown plumage of the tawny owl ( Strix aluco ) allows it to lie in wait among
17922-417: 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
18096-464: The exact number of pairs and individuals is not definitely known. The World Owl Trust stated that they believe some eagle-owls occurring in North England and Scotland are naturally occurring, making the flight of roughly 350 to 400 km (220 to 250 mi) from the west coast of Norway to Shetland and the east coast of Scotland, as well as possibly from the coasts of the Netherlands and Belgium to
18270-1158: The exact placement within Telluraves is disputed. See below cladogram : Cathartiformes (New World vultures) [REDACTED] Accipitriformes ( hawks and relatives) [REDACTED] Strigiformes (owls) [REDACTED] Coliiformes (mouse birds) Leptosomiformes (cuckoo roller) Trogoniformes (trogons and quetzals) [REDACTED] Bucerotiformes ( hornbills and relatives) Coraciiformes ( kingfishers and relatives) [REDACTED] Piciformes ( woodpeckers and relatives) Cariamiformes (seriemas) [REDACTED] Falconiformes (falcons) [REDACTED] Psittaciformes (parrots) [REDACTED] Passeriformes (passerines) [REDACTED] Cladogram of Telluraves relationships based on Braun & Kimball (2021) Some 220 to 225 extant species of owls are known, subdivided into two families: 1. true owls or typical owls family ( Strigidae ) and 2. barn-owls family ( Tytonidae ). Some entirely extinct families have also been erected based on fossil remains; these differ much from modern owls in being less specialized or specialized in
18444-400: The family Strigidae has an inner toe that is distinctly shorter than the central one. These different morphologies allow efficiency in capturing prey specific to the different environments they inhabit. The beak of the owl is short, curved, and downward-facing, and typically hooked at the tip for gripping and tearing its prey. Once prey is captured, the scissor motion of the top and lower bill
18618-435: 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
18792-424: The female by flying to them and kneading out a small depression (if soil is present) and making staccato notes and clucking noises. Several potential sites may be presented, with the female selecting one. In Baden-Wurttenberg, Germany, the amount of male nest site visits were found to increase in time spent over the pre-laying breeding season from a mean of 29 minutes to 3 hours with frequent incubation like sitting by
18966-602: The female is brought food at the nest by her mate. A single clutch of white eggs is laid; each egg can measure from 56 to 73 mm (2.2 to 2.9 in) long by 44.2 to 53 mm (1.74 to 2.09 in) in width, and will usually weigh about 75 to 80 g (2.6 to 2.8 oz). In Central Europe , eggs average 59.8 mm × 49.5 mm (2.35 in × 1.95 in), and in Siberia , eggs average 59.4 mm × 50.1 mm (2.34 in × 1.97 in). Their eggs are only slightly larger than those of snowy owls and
19140-410: The female spends all her time brooding at the nest. After this point, the female gradually resumes hunting from both herself and the young and thus provides a greater range of food for the young. While it may seem contrary to the species’ highly territorial nature, there is one verified cases of polygamy in Germany, with a male apparently mating with two females, and cooperative brooding in Spain, with
19314-478: 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
19488-417: The flapping of the wing down to a nearly silent mechanism. The serrations are more likely reducing aerodynamic disturbances, rather than simply reducing noise. The surface of the flight feathers is covered with a velvety structure that absorbs the sound of the wing moving. These unique structures reduce noise frequencies above 2 kHz, making the sound level emitted drop below the typical hearing spectrum of
19662-442: The food supply to the chicks. Many nesting attempts produce two fledglings, indicating that siblicide is not as common as in other birds of prey, especially a few species of eagles . In Spain, males are thought to be the first egg laid to reduce the likelihood of sibling aggression due to the size difference, thus the younger female hatchling is less likely to be killed since it is similar in size to its older sibling. Apparently,
19836-529: 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. 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
20010-644: 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 hold more prey, so are prone to less frequent human disturbance. In
20184-560: 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
20358-713: The horned owls greater numbers in modern times. Eurasian eagle-owls are listed in Appendix II of the Convention on International Trade in Endangered Species (CITES) meaning international trade (including in parts and derivatives) is regulated. The Eurasian eagle-owl is one of the longest-living owls. It can live for up to 20 years in the wild. A 19-year-old was once considered the oldest ringed eagle-owl. Some studies posited that, in protected areas, lifespans ranging 15–20 years may not be uncommon. A record-breaking specimen,
20532-405: 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. The great size, bulky, barrel-shaped build, erect ear tufts, and orange eyes render this as
20706-445: The indigestible parts of their prey (such as bones, scales, and fur) in the form of pellets . These "owl pellets" are plentiful and easy to interpret, and are often sold by companies to schools for dissection by students as a lesson in biology and ecology. Owl eggs typically have a white color and an almost spherical shape, and range in number from a few to a dozen, depending on species and the particular season; for most, three or four
20880-416: The installation of floats. Eyesight is a particular characteristic of the owl that aids in nocturnal prey capture. Owls are part of a small group of birds that live nocturnally, but do not use echolocation to guide them in flight in low-light situations. Owls are known for their disproportionally large eyes in comparison to their skulls. An apparent consequence of the evolution of an absolutely large eye in
21054-465: The iris can range into an orange-yellow colour (most closely related species generally have yellowish irises, excluding the Indian eagle-owl ). 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
21228-728: The islands). 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
21402-452: The land bridge between Britain and continental Europe may have been responsible for their extirpation as they only disperse over limited distances, although early human persecution presumably played a role as well. Some reportages of eagle-owls in Britain have been revealed to actually be great horned owls or Indian eagle-owls, the latter a particularly popular owl in falconry circuits. Some breeding pairs do still occur in Britain, though
21576-471: The large-sized retinal image. Thus, the primary nocturnal function in the vision of the owl is due to its large posterior nodal distance; retinal image brightness is only maximized to the owl within secondary neural functions. These attributes of the owl cause its nocturnal eyesight to be far superior to that of its average prey. Owls exhibit specialized hearing functions and ear shapes that also aid in hunting. They are noted for asymmetrical ear placements on
21750-569: The largely forested Altai Krai region of Russia were found to be on the ground, usually at the base of pines . This species does not often use other bird’s nests as does the great horned owl, which often prefers nests built by other animals over any other nesting site. The Eurasian eagle-owl has been recorded in singular cases using nests built by common buzzards ( Buteo buteo ), golden eagle, greater spotted ( Clanga clanga ) and white-tailed eagles ( Haliaeetus albicilla ), common ravens ( Corvus corax ) and black storks ( Ciconia nigra ). Among
21924-442: The largest of any bird's, preventing blood supply from being cut off while they rotate their necks. Other anastomoses between the carotid and vertebral arteries support this effect. The smallest owl—weighing as little as 31 g ( 1 + 3 ⁄ 32 oz) and measuring some 13.5 cm ( 5 + 1 ⁄ 4 in)—is the elf owl ( Micrathene whitneyi ). Around the same diminutive length, although slightly heavier, are
22098-533: The largest owls, the great horned owl ( Bubo virginianus ), needs a force over 130 N to release prey in its talons. An owl's talons, like those of most birds of prey, can seem massive in comparison to the body size outside of flight. The Tasmanian masked owl has some of the proportionally longest talons of any bird of prey; they appear enormous in comparison to the body when fully extended to grasp prey. An owl's claws are sharp and curved. The family Tytonidae has inner and central toes of about equal length, while
22272-413: The leading edge of owls' remiges muffle an owl's wing beats, allowing an owl's flight to be practically silent. Some fish-eating owls, for which silence has no evolutionary advantage, lack this adaptation. An owl's sharp beak and powerful talons allow it to kill its prey before swallowing it whole (if it is not too big). Scientists studying the diets of owls are helped by their habit of regurgitating
22446-796: The lesser known long-whiskered owlet ( Xenoglaux loweryi ) and Tamaulipas pygmy owl ( Glaucidium sanchezi ). The largest owls are two similarly sized eagle owls ; the Eurasian eagle-owl ( Bubo bubo ) and Blakiston's fish owl ( Bubo blakistoni ). The largest females of these species are 71 cm (28 in) long, have a 190 cm (75 in) wing span, and weigh 4.2 kg ( 9 + 1 ⁄ 4 lb). Different species of owls produce different sounds; this distribution of calls aids owls in finding mates or announcing their presence to potential competitors, and also aids ornithologists and birders in locating these birds and distinguishing species. As noted above, their facial discs help owls to funnel
22620-585: The lives of eagle-owls. Electrocution was the greatest cause of mortality in 68% of 25 published studies, and accounted, on average, for 38.2% of the reported eagle-owl deaths. This was particularly true in the Italian Alps, where the number of dangerous, uninsulated pylons near nests was extremely high, but is highly problematic almost throughout the species’ European distribution. In one telemetry study, 55% of 27 dispersing young were electrocuted within 1 year of their release from captivity, while electrocution rates of wild-born young are even higher. Mortality in
22794-514: 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
22968-494: The main target), or shot intentionally. While the eagle-owl remains reasonably numerous in some parts of its habitat where nature is still relatively little disturbed by human activity, such as the sparsely populated regions of Russia and Scandinavia , concern has been expressed about the future of the Eurasian eagle-owl in Western and Central Europe. There, very few areas are not heavily modified by human civilisation, thus exposing
23142-407: The male great horned owl. Courtship in the Eurasian eagle-owl may involve bouts of "duetting", with the male sitting upright and the female bowing as she calls. There may be mutual bowing, billing and fondling before the female flies to a perch where coitus occurs, usually taking place several times over the course of a few minutes. The male selects breeding sites and advertises their potential to
23316-473: The male. Like all owls, Eurasian eagle-owls do not build nests or add material but nest on the surface or material already present. Eurasian eagle-owls normally nest on rocks or boulders, most often utilizing cliff ledges and steep slopes, as well as crevices, gullies , holes or caves . Rocky areas that also prove concealing woodlots as well as, for hunting purposes, that border river valleys and grassy scrubland may be especially attractive. If only low rubble
23490-426: 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
23664-399: The mean number of fledglings per nest was 1.67. In central Europe, the mean number of fledglings per nest was between 1.8 and 1.9. The mean fledgling rate in the Italian Alps was 1.89, thus being similar. In the Italian Alps, heavier rainfall during breeding decreased fledgling success because it inhibited the ability of the parents to hunt and potentially exposed nestlings to hypothermia. In
23838-866: The most part seems to have taken place in Eurasia. In the Americas, rather, an expansion of immigrant lineages of ancestral typical owls occurred. The supposed fossil herons "Ardea" perplexa (Middle Miocene of Sansan, France) and "Ardea" lignitum (Late Pliocene of Germany) were more probably owls; the latter was apparently close to the modern genus Bubo . Judging from this, the Late Miocene remains from France described as "Ardea" aureliensis should also be restudied. The Messelasturidae , some of which were initially believed to be basal Strigiformes, are now generally accepted to be diurnal birds of prey showing some convergent evolution toward owls. The taxa often united under Strigogyps were formerly placed in part with
24012-404: The nest between the Eurasian eagle-owl and its Nearctic counterpart may be correlated to variation in the extent of nest predation that the species endured during the evolutionary process. The eggs are normally laid at intervals of three days and are incubated only by the female. Laying generally begins in late winter but may be later in the year in colder habitats. During the incubation period,
24186-404: 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. Vocal activity
24360-486: The nest. Therefore, females may have a larger mass to allow them to go for a longer period of time without starving. For example, one hypothesized sexual role is that larger females are more capable of dismembering prey and feeding it to their young, hence female owls are larger than their male counterparts. A different theory suggests that the size difference between male and females is due to sexual selection: since large females can choose their mate and may violently reject
24534-439: The nominate subspecies of great horned owl, while similar in size to those of spot-bellied eagle-owls and Blakiston's fish owls. The Eurasian eagle-owl’s eggs are noticeably larger than those of Indian eagle-owl and pharaoh eagle-owls. Usually clutch size is one or two, rarely three or four, and exceptionally to six. The average number of eggs laid varies with latitude in Europe. Clutch size ranges from 2.02 to 2.14 in Spain and
24708-643: The northern Middle East , the montane upper part of South Asia , China , Korea and in Japan ; in addition, an estimated 12 to 40 pairs are thought to reside in the United Kingdom as of 2016 (where they are arguably non-native), a number which may be on the rise, and have successfully bred in the UK since at least 1996. Tame eagle-owls have occasionally been used in pest control because of their size to deter large birds such as gulls from nesting. The Eurasian eagle-owl
24882-457: The owl's usual prey and also within the owl's own best hearing range. This optimizes the owl's ability to silently fly to capture prey without the prey hearing the owl first as it flies, and to hear any noise the prey makes. It also allows the owl to monitor the sound output from its flight pattern. The disadvantage of such feather adaptations for barn owls is that their feathers are not waterproof. The adaptations mean that barn owls do not use
25056-478: The owls' asymmetrically placed ear cavities. Most birds of prey have eyes on the sides of their heads, but the stereoscopic nature of the owl's forward-facing eyes permits the greater sense of depth perception necessary for low-light hunting. Owls have binocular vision , but they must rotate their entire heads to change the focus of their view because, like most birds, their eyes are fixed in their sockets. Owls are farsighted and cannot clearly see anything nearer than
25230-507: The owls, specifically the Sophiornithidae; they appear to be Ameghinornithidae instead. For fossil species and paleosubspecies of extant taxa , see the genus and species articles. For a full list of extant and recently extinct owls, see the article List of owl species . Eurasian eagle-owl See text . The Eurasian eagle-owl ( Bubo bubo ) is a species of eagle-owl , a type of bird that resides in much of Eurasia . It
25404-424: The point at which the chicks venture out of the nest is driven by the location of the nest. In elevated nest sites, chicks usually wander out of the nest at 5 to as late as 7 weeks of age, but have been recorded leaving the nest if the nest is on the ground as early as 22 to 25 days old. The chicks can walk well at 5 weeks of age and by 7 weeks are taking short flights. Hunting and flying skills are not tested prior to
25578-485: The proper insulation of electric wires and pylons in areas where the species is present. As this measure is labour-intensive and therefore rather expensive, few efforts have actually been made to insulate pylons in areas with few fiscal resources devoted to conservation such as rural Spain. In Sweden, a mitigation project was launched to insulate transformers that are frequently damaged by eagle-owl electrocution. Large reintroduction programs were instituted in Germany after
25752-655: The reintroduced population of eagle-owls in Eifel , Germany, occupied territories produced an average of 1.17 fledglings, but not all occupying pairs attempted to breed, with about 23% of those attempting to breed being unsuccessful. In slightly earlier studies, possibly due to higher persecution rates, the mean number of young leaving the nest was often lower, such as 1.77 in Bavaria , Germany, 1.1 in lower Austria , and 0.6 in southern Sweden. An experimental supplemental feeding program to young eagle-owls on two small Norwegian islands were found to increase mean numbers of fledglings from
25926-714: 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,
26100-496: 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
26274-481: 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
26448-428: The same size as their prey. This has also been observed in other predatory birds, which suggests that owls with smaller bodies and long wing chords have been selected for because of the increased agility and speed that allows them to catch their prey. Another popular theory suggests that females have not been selected to be smaller like male owls because of their sexual roles. In many species, female owls may not leave
26622-441: The skull in some genera. Owls can have either internal or external ears, both of which are asymmetrical. Asymmetry has not been reported to extend to the middle or internal ear of the owl. Asymmetrical ear placement on the skull allows the owl to pinpoint the location of its prey. This is especially true for strictly nocturnal species such as the barn owls Tyto or Tengmalm's owl. With ears set at different places on its skull, an owl
26796-402: 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
26970-444: 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
27144-507: 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 . 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
27318-464: The sound of prey to their ears. In many species, these discs are placed asymmetrically, for better directional location. Owl plumage is generally cryptic , although several species have facial and head markings, including face masks, ear tufts , and brightly colored irises . These markings are generally more common in species inhabiting open habitats, and are thought to be used in signaling with other owls in low-light conditions. Sexual dimorphism
27492-473: The south. Although not migratory, eagle-owls can disperse some notable distances in young birds seeking a territory. Prior studies of eagle-owl distribution have indicated a strong reluctance to cross large bodies of water in the species. Many authorities state that the Eurasian eagle-owls occurring in Britain are individuals that have escaped from captivity. While, until the 19th century, wealthy collectors may have released unwanted eagle-owls, despite press to
27666-495: 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). Besides
27840-418: The specimens with or without the puffed up white patch. In January and February, the primary function for vocalization becomes for the purpose of courtship. More often than not, eagle-owls will pair for life but usually engage in courtship rituals annually, most likely to re-affirm pair bonds. When calling for the purposes of courtship, males tend to bow and hoot loudly but do so in a less contorted manner than
28014-495: 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
28188-447: The talons and beak of the owl do the final work. The owl kills its prey using these talons to crush the skull and knead the body. The crushing power of an owl's talons varies according to prey size and type, and by the size of the owl. The burrowing owl ( Athene cunicularia ), a small, partly insectivorous owl, has a release force of only 5 N. The larger barn owl ( Tyto alba ) needs a force of 30 N to release its prey, and one of
28362-425: 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. The feathers of
28536-421: The torso. This ability keeps bodily movement at a minimum, thus reduces the amount of sound the owl makes as it waits for its prey. Owls are regarded as having the most frontally placed eyes among all avian groups, which gives them some of the largest binocular fields of vision. Owls are farsighted and cannot focus on objects within a few centimetres of their eyes. These mechanisms are only able to function due to
28710-503: The twilight hours of dawn and dusk; one example is the pygmy owl ( Glaucidium ). A few owls are active during the day, also; examples are the burrowing owl ( Speotyto cunicularia ) and the short-eared owl ( Asio flammeus ). Much of the owls' hunting strategy depends on stealth and surprise. Owls have at least two adaptations that aid them in achieving stealth. First, the dull coloration of their feathers can render them almost invisible under certain conditions. Secondly, serrated edges on
28884-452: 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
29058-466: 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
29232-406: The world and across a multitude of ecosystems, their hunting skills and characteristics vary slightly from species to species, though most characteristics are shared among all species. Most owls share an innate ability to fly almost silently and also more slowly in comparison to other birds of prey. Most owls live a mainly nocturnal lifestyle and being able to fly without making any noise gives them
29406-483: The young eagle-owls leaving the nest. Young Eurasian eagle-owls leave the nest by 5–6 weeks of age and typically can be flying weakly (a few metres) by about 7–8 weeks of age. Normally, they are cared for at least another month. By the end of the month, the young eagle-owls are quite assured fliers. A few cases have been confirmed of adult eagle-owls in Spain feeding and caring for postfledgling juvenile eagle-owls that were not their own. A study from southern France found
29580-486: 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
29754-463: Was banded in the wild and later encountered at the age of 27 years and 9 months. Like many other bird species, they can live much longer in captivity, where they don't endure difficult natural conditions. They may have survived up to 68 years in zoo collections. Healthy adults normally have no natural predators, thus are considered apex predators . The leading causes of death are man-made: electrocution, traffic accidents, and shooting frequently claim
29928-533: 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. 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
30102-402: Was the highest growth rate of any studied owl and faster than either snowy or great horned owls. Body mass increased fourteen times over from 5 days old to 60 days old in this study. The male continues to bring prey, leaving it on or around the nest, and the female feeds the nestlings, tearing up the food into suitably sized pieces. The female resumes hunting after about 3 weeks, which increases
30276-473: Was the lowest of any European owl per one study. One species was attributed with an even lower clutch size in North America, the great grey owl with a mean of 2.6, but the mean clutch size was much higher for the same species in Europe, at 4.05. In Spain, incubation is from mid-January to mid-March, hatching and early nestling period is from late March to early April, fledging and postfledging dependence can range from mid-April to August, and territorial/courtship
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