191-465: Aerie (a variant of eyrie ) is the bird nest of an eagle, falcon, hawk, or other bird of prey. Aerie may also refer to: Bird nest A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American robin or Eurasian blackbird , or
382-425: 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
573-516: A bird attacking a person near its nest is said to swoop the person. The Australian magpie is particularly well known for this behavior. Nests can become home to many other organisms including parasites and pathogens. The excreta of the fledglings also pose a problem. In most passerines, the adults actively dispose the fecal sacs of young at a distance or consume them. This is believed to help prevent ground predators from detecting nests. Young birds of prey however usually void their excreta beyond
764-512: A broken stump, or into a shallow depression on a branch—typically where an upward-pointing branch died and fell off, leaving a small scar or knot-hole. Brood parasites , such as the New World cowbirds , the honeyguides , and many of the Old World and Australasian cuckoos , lay their eggs in the active nests of other species. The simplest nest construction is the scrape , which
955-453: A combination of their beaks and feet to excavate burrow nests. The tunnel is started with the beak; the bird either probes at the ground to create a depression, or flies toward its chosen nest site on a cliff wall and hits it with its bill. The latter method is not without its dangers; there are reports of kingfishers being fatally injured in such attempts. Some birds remove tunnel material with their bills, while others use their bodies or shovel
1146-424: A cup nest, has at most only a shallow depression to house the eggs. The platform nest is a large structure, often many times the size of the (typically large) bird which has built it. Depending on the species, these nests can be on the ground or elevated. In the case of raptor nests, or eyries (also spelled aerie ), these are often used for many years, with new material added each breeding season. In some cases,
1337-405: 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
1528-407: A different type of mound nest. Using their beaks to pull material towards them, they fashion a cone-shaped pile of mud between 15–46 cm (6–18 in) tall, with a small depression in the top to house their single egg. The height of the nest varies with the substrate upon which it is built; those on clay sites are taller on average than those on dry or sandy sites. The height of the nest and
1719-465: 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
1910-442: 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
2101-440: A mere 2 cm (0.8 in) across and 2–3 cm (0.8–1.2 in) high. At the other extreme, some nest mounds built by the dusky scrubfowl measure more than 11 m (36 ft) in diameter and stand nearly 5 m (16 ft) tall. The study of birds' nests is known as caliology . Not all bird species build nests. Some species lay their eggs directly on the ground or rocky ledges, while brood parasites lay theirs in
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#17327765579692292-446: A number of studies have attempted to determine whether secondary cavity nesters preferentially choose cavities with entrance holes facing certain directions, the results remain inconclusive. While some species appear to preferentially choose holes with certain orientations, studies (to date) have not shown consistent differences in fledging rates between nests oriented in different directions. Cavity-dwelling species have to contend with
2483-530: 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
2674-533: 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
2865-407: 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,
3056-453: A sheltered microclimate and concentrated food sources for invertebrates. A global checklist lists eighteen invertebrate orders that occur in bird nests. Many birds may nest close to human habitations. In addition to nest boxes which are often used to encourage cavity nesting birds (see below), other species have been specially encouraged : for example nesting white storks have been protected and held in reverence in many cultures, and
3247-423: A small number are made of mud or saliva . Many passerines and a few non-passerines, including some hummingbirds and some swifts, build this type of nest. Small bird species in more than 20 passerine families, and a few non-passerines—including most hummingbirds, kinglets and crests in the genus Regulus , some tyrant flycatchers and several New World warblers —use considerable amounts of spider silk in
3438-590: 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
3629-618: 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
3820-491: 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
4011-450: 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
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#17327765579694202-609: 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 ,
4393-496: 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,
4584-657: 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
4775-532: A vertical chamber within the trunk. The size and shape of the chamber depends on species, and the entrance hole is typically only as large as is needed to allow access for the adult birds. While wood chips are removed during the excavation process, most species line the floor of the cavity with a fresh bed of them before laying their eggs. Trogons excavate their nests by chewing cavities into very soft dead wood; some species make completely enclosed chambers (accessed by upward-slanting entrance tunnels), while others—like
4966-399: 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,
5157-455: 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
5348-415: Is a mound built of stones, gathered one at a time by the pair, using their beaks. These stones, which may weigh as much as 450 g (about a pound) each, are dropped into the shallow water of a lake, making a cone -shaped pile which can measure as much as 4 m (43 sq ft) at the bottom and 1 m (11 sq ft) at the top, and 0.6 m (2.0 ft) in height. The total combined weight of
5539-467: 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,
5730-499: 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,
5921-419: Is also some evidence that fungal rot may make the wood on the underside of leaning trunks and branches easier to excavate. Most woodpeckers use a cavity for only a single year. The endangered red-cockaded woodpecker is an exception; it takes far longer—up to two years—to excavate its nest cavity, and may reuse it for more than two decades. The typical woodpecker nest has a short horizontal tunnel which leads to
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6112-403: 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 )
6303-532: 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,
6494-604: Is critical for the survival of the developing eggs, as there are no nests to keep them from rolling off the side of the cliff. Presumably because of the vulnerability of their unprotected eggs, parent birds of these auk species rarely leave them unattended. Nest location and architecture is strongly influenced by local topography and other abiotic factors. King penguins and emperor penguins also do not build nests; instead, they tuck their eggs and chicks between their feet and folds of skin on their lower bellies. They are thus able to move about while incubating, though in practice only
6685-505: 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
6876-489: 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
7067-657: 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
7258-453: 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
7449-431: Is merely a shallow depression in soil or vegetation. This nest type, which typically has a rim deep enough to keep the eggs from rolling away, is sometimes lined with bits of vegetation, small stones , shell fragments or feathers . These materials may help to camouflage the eggs or may provide some level of insulation; they may also help to keep the eggs in place, and prevent them from sinking into muddy or sandy soil if
7640-506: 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
7831-520: 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
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8022-468: 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
8213-423: 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
8404-476: Is pendant, suspended from a single point hanging from branch while many other birds incorporate more than one branch to support the nest. The sphere nest is a roundish structure; it is completely enclosed, except for a small opening which allows access. Most spherical nests are woven out of plant material. Spider webs are also frequently used, upon which other material such as lichens may be stuck for camouflage. The cape penduline tit incorporates false entrances,
8595-588: 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
8786-495: 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
8977-629: 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
9168-399: Is reduced by an additional 25%. The insulating factor of nest lining is apparently so critical to egg survival that some species, including Kentish plovers , will restore experimentally altered levels of insulation to their pre-adjustment levels (adding or subtracting material as necessary) within 24 hours. In warm climates, such as deserts and salt flats , heat rather than cold can kill
9359-411: 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
9550-456: 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
9741-467: 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
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#17327765579699932-1210: Is some evidence that increased vulnerability may lead some burrow-nesting species to form colonies, or to nest closer to rival pairs in areas of high predation than they might otherwise do. The cavity nest is a chamber, typically in living or dead wood, but sometimes in the trunks of tree ferns or large cacti , including saguaro . In tropical areas, cavities are sometimes excavated in arboreal insect nests. A relatively small number of species, including woodpeckers , trogons , some nuthatches and many barbets , can excavate their own cavities. Far more species—including parrots, tits , bluebirds , most hornbills , some kingfishers, some owls , some ducks and some flycatchers—use natural cavities, or those abandoned by species able to excavate them; they also sometimes usurp cavity nests from their excavating owners. Those species that excavate their own cavities are known as "primary cavity nesters", while those that use natural cavities or those excavated by other species are called "secondary cavity nesters". Both primary and secondary cavity nesters can be enticed to use nest boxes (also known as bird houses); these mimic natural cavities, and can be critical to
10123-500: 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
10314-517: 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,
10505-656: 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
10696-675: 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
10887-599: 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
11078-431: 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
11269-652: 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
11460-475: 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
11651-423: The burrowing parakeet can extend for more than three meters (nearly 10 ft). Some species, including the ground-nesting puffbirds , prefer flat or gently sloping land, digging their entrance tunnels into the ground at an angle. In a more extreme example, the D'Arnaud's barbet digs a vertical tunnel shaft more than a meter (39 in) deep, with its nest chamber excavated off to the side at some height above
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#173277655796911842-433: The convective cooling caused by cold winds, but shallow enough that they and the parent bird are not too exposed to the cooling influences of ground temperatures, particularly where the permafrost layer rises to mere centimeters below the nest. Studies have shown that an egg within a scrape nest loses heat 9% more slowly than an egg placed on the ground beside the nest; in such a nest lined with natural vegetation, heat loss
12033-443: The crab plover , miners and leaftossers are among the species which use burrow nests. Most burrow nesting species dig a horizontal tunnel into a vertical (or nearly vertical) dirt cliff, with a chamber at the tunnel's end to house the eggs. The length of the tunnel varies depending on the substrate and the species; sand martins make relatively short tunnels ranging from 50–90 cm (20–35 in), for example, while those of
12224-549: 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,
12415-412: 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
12606-527: The root buttresses of trees, and kagus lay theirs on a pile of dead leaves against a log, tree trunk or vegetation. Marbled godwits stomp a grassy area flat with their feet, then lay their eggs, while other grass-nesting waders bend vegetation over their nests so as to avoid detection from above. Many female ducks, particularly in the northern latitudes , line their shallow scrape nests with down feathers plucked from their own breasts, as well as with small amounts of vegetation. Among scrape-nesting birds,
12797-412: The sand in the place they have chosen to site their nest, while skimmers build their scrapes with their feet, kicking sand backwards while resting on their bellies and turning slowly in circles. The ostrich also scratches out its scrape with its feet, though it stands while doing so. Many tinamous lay their eggs on a shallow mat of dead leaves they have collected and placed under bushes or between
12988-523: 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
13179-543: The three-banded courser and Egyptian plover are unique in their habit of partially burying their eggs in the sand of their scrapes. Burying eggs as a form of incubation reaches its zenith with the Australasian megapodes . Several megapode species construct enormous mound nests made of soil, branches, sticks, twigs and leaves, and lay their eggs within the rotting mass. The heat generated by these mounds, which are in effect giant compost heaps , warms and incubates
13370-532: 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
13561-400: 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 )
13752-588: 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
13943-477: 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
14134-475: 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
14325-588: 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
14516-480: 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
14707-782: 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
14898-508: 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
15089-725: 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
15280-634: 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
15471-540: 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
15662-400: 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
15853-399: The area around the nest. Most species with this type of nest have precocial young, which quickly leave the nest upon hatching. In cool climates (such as in the high Arctic or at high elevations), the depth of a scrape nest can be critical to both the survival of developing eggs and the fitness of the parent bird incubating them. The scrape must be deep enough that eggs are protected from
16044-514: 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
16235-588: 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
16426-443: 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
16617-690: The bird directly. Birds have also evolved nest sanitation measures to reduce the effects of parasites and pathogens on nestlings. Some aquatic species such as grebes are very careful when approaching and leaving the nest so as not to reveal the location. Some species will use leaves to cover up the nest prior to leaving. Ground birds such as plovers may use broken wing or rodent run displays to distract predators from nests. Many species attack predators or apparent predators near their nests. Kingbirds attack other birds that come too close. In North America, northern mockingbirds , blue jays , and Arctic terns can peck hard enough to draw blood. In Australia,
16808-494: 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
16999-591: 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
17190-434: 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
17381-400: The breeding season, the male digs a pit into his mound and sticks his head in. If the mound's core temperature is a bit low, he adds fresh moist material to the mound, and stirs it in; if it is too high, he opens the top of the mound to allow some of the excess heat to escape. This regular monitoring also keeps the mound's material from becoming compacted, which would inhibit oxygen diffusion to
17572-445: The burrows of prairie dogs , ground squirrels , badgers or tortoises , China's endemic white-browed tits use the holes of ground-nesting rodents and common kingfishers occasionally nest in rabbit burrows. Burrow nests are particularly common among seabirds at high latitudes, as they provide protection against both cold temperatures and predators. Puffins , shearwaters , some megapodes, motmots , todies , most kingfishers ,
17763-403: The circular, often water-filled trench which surrounds it (the result of the removal of material for the nest) help to protect the egg from fluctuating water levels and excessive heat at ground level. In East Africa, for example, temperatures at the top of the nest mound average some 20 °C (36 °F) cooler than those of the surrounding ground. The base of the horned coot 's enormous nest
17954-521: 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
18145-564: 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
18336-418: 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
18527-400: The cold nights. During hot summer months, the malleefowl opens its nest mound only in the cool early morning hours, allowing excess heat to escape before recovering the mound completely. One recent study showed that the sex ratio of Australian brushturkey hatchlings correlated strongly with mound temperatures; females hatched from eggs incubated at higher mean temperatures. Flamingos make
18718-478: The construction of their nests. The lightweight material is strong and extremely flexible, allowing the nest to mold to the adult during incubation (reducing heat loss), then to stretch to accommodate the growing nestlings; as it is sticky, it also helps to bind the nest to the branch or leaf to which it is attached. Many swifts and some hummingbirds use thick, quick-drying saliva to anchor their nests. The chimney swift starts by dabbing two globs of saliva onto
18909-835: 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
19100-648: 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
19291-416: 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
19482-449: The danger of predators accessing their nest, catching them and their young inside and unable to get out. They have a variety of methods for decreasing the likelihood of this happening. Red-cockaded woodpeckers peel bark around the entrance, and drill wells above and below the hole; since they nest in live trees, the resulting flow of resin forms a barrier that prevents snakes from reaching the nests. Red-breasted nuthatches smear sap around
19673-526: 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,
19864-553: The developing embryos. In such places, scrapes are shallower and tend to be lined with non-vegetative material (including shells, feathers, sticks and soil), which allows convective cooling to occur as air moves over the eggs. Some species, such as the lesser nighthawk and the red-tailed tropicbird , help reduce the nest's temperature by placing it in partial or full shade. Others, including some shorebirds, cast shade with their bodies as they stand over their eggs. Some shorebirds also soak their breast feathers with water and then sit on
20055-586: The dirt out with one or both feet. Female paradise-kingfishers are known to use their long tails to clear the loose soil. Some crepuscular petrels and prions are able to identify their own burrows within dense colonies by smell. Sand martins learn the location of their nest within a colony, and will accept any chick put into that nest until right before the young fledge. Not all burrow-nesting species incubate their young directly. Some megapode species bury their eggs in sandy pits dug where sunlight, subterranean volcanic activity, or decaying tree roots will warm
20246-506: 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
20437-401: 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
20628-406: 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,
20819-585: 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
21010-576: 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
21201-487: 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
21392-405: 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 )
21583-419: 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
21774-401: The eggs and make it more difficult for the chicks to emerge after hatching. The malleefowl , which lives in more open forest than do other megapodes, uses the sun to help warm its nest as well—opening the mound at midday during the cool spring and autumn months to expose the plentiful sand incorporated into the nest to the sun's warming rays, then using that warm sand to insulate the eggs during
21965-420: The eggs, providing moisture to enable evaporative cooling . Parent birds keep from overheating themselves by gular panting while they are incubating, frequently exchanging incubation duties, and standing in water when they are not incubating. The technique used to construct a scrape nest varies slightly depending on the species. Beach-nesting terns, for instance, fashion their nests by rocking their bodies on
22156-408: The eggs. The crab plover also uses a burrow nest, the warmth of which allows it to leave the eggs unattended for as long as 58 hours. Predation levels on some burrow-nesting species can be quite high; on Alaska 's Wooded Islands, for example, river otters munched their way through some 23 percent of the island's fork-tailed storm-petrel population during a single breeding season in 1977. There
22347-426: The eggs. The nest heat results from the respiration of thermophilic fungi and other microorganisms . The size of some of these mounds can be truly staggering; several of the largest—which contain more than 100 cubic metres (130 cu yd) of material, and probably weigh more than 50 tons (45,000 kg) —were initially thought to be Aboriginal middens. In most mound-building species, males do most or all of
22538-569: The elaborately woven hanging nest of the Montezuma oropendola or the village weaver —that is too restrictive a definition. For some species, a nest is simply a shallow depression made in sand; for others, it is the knot-hole left by a broken branch, a burrow dug into the ground, a chamber drilled into a tree, an enormous rotting pile of vegetation and earth, a shelf made of dried saliva or a mud dome with an entrance tunnel. The smallest bird nests are those of some hummingbirds , tiny cups which can be
22729-461: The emperor penguin regularly does so. Emperor penguins breed during the harshest months of the Antarctic winter, and their mobility allows them to form huge huddled masses which help them to withstand the extremely high winds and low temperatures of the season. Without the ability to share body heat (temperatures in the centre of tight groups can be as much as 10C above the ambient air temperature),
22920-569: 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
23111-460: The entrance hole to a narrow slit. A few birds are known to use the nests of insects within which they create a cavity in which they lay their eggs. These include the rufous woodpecker which nests in the arboreal nests of Crematogaster ants and the collared kingfisher which uses termite nests. The cup nest is smoothly hemispherical inside, with a deep depression to house the eggs. Most are made of pliable materials—including grasses—though
23302-434: The entrance holes to their nests, while white-breasted nuthatches rub foul-smelling insects around theirs. Eurasian nuthatches wall up part of their entrance holes with mud, decreasing the size and sometimes extending the tunnel part of the chamber. Most female hornbills seal themselves into their cavity nests, using a combination of mud (in some species brought by their mates), food remains and their own droppings to reduce
23493-417: 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
23684-471: 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
23875-450: The extravagantly plumed resplendent quetzal —construct more open niches. In most trogon species, both sexes help with nest construction. The process may take several months, and a single pair may start several excavations before finding a tree or stump with wood of the right consistency. Species which use natural cavities or old woodpecker nests sometimes line the cavity with soft material such as grass, moss, lichen, feathers or fur. Though
24066-435: 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
24257-424: 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
24448-607: 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
24639-410: 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
24830-478: 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
25021-442: 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,
25212-544: 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
25403-535: The ground and typically in the open, with little to hide them. The eggs of most ground-nesting birds (including those that use scrape nests) are cryptically coloured to help camouflage them when the adult is not covering them; the actual colour generally corresponds to the substrate on which they are laid. Brooding adults also tend to be well camouflaged, and may be difficult to flush from the nest. Most ground-nesting species have well-developed distraction displays , which are used to draw (or drive) potential predators from
25594-644: 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
25785-560: 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
25976-733: 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,
26167-405: 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
26358-469: 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
26549-737: 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
26740-452: 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
26931-569: 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
27122-585: 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
27313-514: 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
27504-499: 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
27695-500: The majority of nest-building species the female does most or all of the nest construction, in others both partners contribute; sometimes the male builds the nest and the hen lines it. In some polygynous species, however, the male does most or all of the nest building. The nest may also form a part of the courtship display such as in weaver birds . The ability to choose and maintain good nest sites and build high quality nests may be selected for by females in these species. In some species
27886-407: 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
28077-473: 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
28268-426: 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
28459-481: The mass of the incubating parent. This is known as an allometric relationship. Nest walls are constructed with an adequate quantity of nesting material so that the nest will be capable of supporting the contents of the nest. Nest thickness, nest mass and nest dimensions therefore correlate with the mass of the adult bird. The flow-on consequence of this is that nest insulation is also related to parent mass. The saucer or plate nest, though superficially similar to
28650-399: 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
28841-548: The mound's stones may approach 1.5 tons (1,400 kg). Once the mound has been completed, a sizable platform of aquatic vegetation is constructed on top. The entire structure is typically reused for many years. Soil plays a different role in the burrow nest; here, the eggs and young—and in most cases the incubating parent bird—are sheltered under the earth. Most burrow-nesting birds excavate their own burrows, but some use those excavated by other species and are known as secondary nesters; burrowing owls , for example, sometimes use
29032-404: 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,
29223-452: The nest construction and maintenance. Using his strong legs and feet, the male scrapes together material from the area around his chosen nest site, gradually building a conical or bell-shaped pile. This process can take five to seven hours a day for more than a month. While mounds are typically reused for multiple breeding seasons, new material must be added each year to generate the appropriate amount of heat. A female will begin to lay eggs in
29414-404: 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
29605-399: The nest is accidentally flooded. Ostriches, most tinamous , many ducks, most shorebirds , most terns , some falcons , pheasants , quail , partridges , bustards and sandgrouse are among the species that build scrape nests. Eggs and young in scrape nests, and the adults that brood them, are more exposed to predators and the elements than those in more sheltered nests; they are on
29796-467: The nest only when the mound's temperature has reached an optimal level. Both the temperature and the moisture content of the mound are critical to the survival and development of the eggs, so both are carefully regulated for the entire length of the breeding season (which may last for as long as eight months), principally by the male. Ornithologists believe that megapodes may use sensitive areas in their mouths to assess mound temperatures; each day during
29987-485: The nesting of peregrine falcons on tall modern or historical buildings has captured popular interest. Colonial breeders produce guano in and around their nesting sites, which is a valuable fertilizer from the Andean Pacific coast and other areas. 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
30178-450: The nests grow large enough to cause structural damage to the tree itself, particularly during bad storms where the weight of the nest can cause additional stress on wind-tossed branches. The pendent nest is an elongated sac woven of pliable materials such as grasses and plant fibers and suspended from a branch. Oropendolas , caciques , orioles , weavers and sunbirds are among the species that weave pendent nests. In weaver birds, this
30369-531: The nests of other birds, letting unwitting "foster parents" do the work of rearing the young. Although nests are primarily used for breeding, they may also be reused in the non-breeding season for roosting and some species build special dormitory nests or roost nests (or winter-nest ) that are used only for roosting. Most birds build a new nest each year, though some refurbish their old nests. The large eyries (or aeries ) of some eagles are platform nests that have been used and refurbished for several years. In
30560-439: 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
30751-657: 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
30942-425: The parent bird carefully making sure to close the actual entrance when leaving the nest. The entrances are lined with spider webs which help seal the openings. Many species of bird conceal their nests to protect them from predators. Some species may choose nest sites that are inaccessible or build the nest so as to deter predators. Bird nests can also act as habitats for other inquiline species which may not affect
31133-413: The penguins would expend far more energy trying to stay warm, and breeding attempts would probably fail. Some crevice-nesting species, including ashy storm-petrel , pigeon guillemot , Eurasian eagle-owl and Hume's tawny owl , lay their eggs in the relative shelter of a crevice in the rocks or a gap between boulders, but provide no additional nest material. Potoos lay their single egg directly atop
31324-424: 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
31515-485: 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
31706-660: 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
31897-714: 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,
32088-496: 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
32279-518: The rims of their nests. Blowflies of the genus Protocalliphora have specialized to become obligate nest parasites with the maggots feeding on the blood of nestlings. Some birds have been shown to choose aromatic green plant material for constructing nests that may have insecticidal properties, while others may use materials such as carnivore scat to repel smaller predators. Some urban birds, house sparrows and house finches in Mexico, have adopted
32470-486: 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
32661-400: The shaft's bottom; this arrangement helps to keep the nest from being flooded during heavy rain. Buff-breasted paradise-kingfishers dig their nests into the compacted mud of active termite mounds, either on the ground or in trees. Specific soil types may favour certain species and it is speculated that several species of bee-eater favor loess soils which are easy to penetrate. Birds use
32852-402: 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
33043-444: 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
33234-516: 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
33425-473: 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
33616-495: 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
33807-418: 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
33998-499: 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
34189-399: The survival of species in areas where natural cavities are lacking. Woodpeckers use their chisel-like bills to excavate their cavity nests, a process which takes, on average, about two weeks. Cavities are normally excavated on the downward-facing side of a branch, presumably to make it more difficult for predators to access the nest, and to reduce the chance that rain floods the nest. There
34380-425: 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
34571-452: 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
34762-743: The use of cigarette butts which contain nicotine and other toxic substances that repel ticks and other ectoparasites. Some birds use pieces of snake slough in their nests. It has been suggested that these may deter some nest predators such as squirrels. Though most birds nest individually, some species—including seabirds , penguins, flamingos, many herons , gulls , terns , weaver , some corvids and some sparrows —gather together in sizeable colonies. Birds that nest colonially may benefit from increased protection against predation. They may also be able to better use food supplies, by following more successful foragers to their foraging sites. In constructing nests, birds act as ecosystem engineers by providing
34953-558: The wall of a chimney or tree trunk. In flight, it breaks a small twig from a tree and presses it into the saliva, angling the twig downwards so that the central part of the nest is the lowest. It continues adding globs of saliva and twigs until it has made a crescent-shaped cup. Cup-shaped nest insulation has been found to be related to nest mass, nest wall thickness, nest depth, nest weave density/porosity, surface area, height above ground and elevation above sea level. More recently, nest insulation has been found to be related to
35144-471: 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
35335-483: 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
35526-405: The young from previous broods may also act as helpers for the adults. Not every bird species builds or uses a nest. Some auks , for instance—including common murre , thick-billed murre and razorbill —lay their eggs directly onto the narrow rocky ledges they use as breeding sites. The eggs of these species are dramatically pointed at one end, so that they roll in a circle when disturbed. This
35717-491: 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
35908-463: 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
36099-542: 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
36290-402: 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
36481-473: 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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