Орал сүңгісі – сипаттамасы мен таралуы

Species of owl

The Ural owl (Strix uralensis) is a large nocturnal owl. It is a member of the true owl family, Strigidae. The Ural owl is a member of the genus Strix, that is also the origin of the family's name under Linnaean taxonomy. Both its common name and scientific name refer to the Ural Mountains of Russia where the type specimen was collected. However, this species has an extremely broad distribution that extends as far west as much of Scandinavia, montane eastern Europe, and, sporadically, central Europe, thence sweeping across the Palearctic broadly through Russia to as far east as Sakhalin and throughout Japan. The Ural owl may include up to 15 subspecies, but most likely the number may be slightly fewer if accounting for clinal variations. This forest owl is typical associated with the vast taiga forest in Eurosiberia, although it ranges to other forest types, including mixed forests and temperate deciduous forest. The Ural owl is something of a dietary generalist like many members of the Strix genus, but it is usually locally reliant on small mammals, especially small rodents such as voles. In terms of its reproductive habits, Ural owls tend to vigorously protect a set territory on which they have historically nested on a variety of natural nest sites, including tree cavities and stumps and nests originally built by other birds but now, in many parts of the range are adapted to nest boxes made by biologists and conservationists. Breeding success is often strongly correlated with prey populations. The Ural owl is considered to be a stable bird species overall, with a conservation status per the IUCN as a least concern species.

Like most Strix species, it has a broad, rounded head with a correspondingly round facial disc, barring a tiny V shaped indentation. The Ural owl has, for an owl, an exceptionally long tail that bears a wedge shaped tip. In colour, it tends to be a plain pale greyish brown to whitish overall (with more detailed description of their variation under subspecies), with a slightly darker grey brown to brown back and mantle with contrasting whitish markings. The underparts are pale cream ochre to grey brown and are boldly (though sometimes more subtly) overlaid with dark brown streaking, without crossbars. Many variations are known in overall plumage colour both at the subspecies level and the individual level. However, the Ural owl usually appears as a rather pale grey brown owl, usually lacking in the warmer, richer colour tones of many other Strix owls, with distinct streaking below. Wingspan can vary in the species from Weight is variable through the European part of the range. Males have been known to weigh from and females have been known to weigh from Voous estimated the typical weight of males and females at and , respectively. Despite having no published weights for adults, Père David's owl (Strix davidi) seems to also be of a similar size to the Ural owl as well. Among standard measurements, in both sexes, wing chord can measure from across the range and tail length can from Among extant owls, only the great grey owl is certain to have a longer tail. Though less frequently measured, the tarsus may range from and, in northern Europe, the total bill length measured from The foot span can regularly reach around in full grown owls. Peak singing times in Finland during springtime are 10 pm 12 am and more intensely at 1 3 am, which differed from the peak times for nest visits. The female has a similar but hoarser and slightly higher pitched song, giving it a more "barking" quality. In total, Swedish biologist reported that about nine different calls were uttered by Ural owls. Despite the range of calls, the species is generally very quiet for a large owl and may not vocalize even at peak times for perhaps up to nearly 2 days. In combination with their large ears, the well developed facial disc shows the importance of sound to hunting to this and other owl who hunt in boreal zones. While the Ural owl was found to be aurally overdeveloped compared to other Strix such as the barred owl (Strix varia) it was found to be underdeveloped in comparison to owls more confined to true boreal type habitats, like the great grey owl and the boreal owl (Aegolius funereus).

The Ural owl is a fairly distinctive looking bird but can be confused for other owls, especially with others in the Strix genus. The extralimital North American barred owl appears quite similar, the main feature differentiating the two being the Ural owl does not have concentric lines on its facial plate. The tawny owl is much smaller with a conspicuously shorter tail and a relatively larger head. The tawny species, which occurs variously in grey, brown and red morphs, has underparts with dark shaft streaks and crossbars, as opposed to the heavy but straight streaking of the Ural owl.

The Ural owl was named by Peter Simon Pallas in 1771 as Strix uralensis, due to the type specimen having been collected in the Ural mountains range. While the Urals fall around the middle of the species' distribution, some authors such as Karel Voous lamented that a more broadly appropriate than Ural owl was not derived for the English common name. The Ural owl is a member of the Strix genus, which are quite often referred to as wood owls. Four owls native to the neotropics are sometimes additionally included with the Strix genus but some authorities have also included these in a separate but related genus, Ciccaba. Strix owls have an extensive fossil record and have long been widely distributed. The genetic relationship of true owls is somewhat muddled and different genetic testings has variously indicated that Strix owls are related to disparate appearing genera like Pulsatrix, Bubo and Asio. The tawny owl is thought to be a close relative of the Ural owl. Authors have hypothesized that the origin of the species divide followed Pleistocene continental glaciations segregated a southwest or southern group in temperate forest (i. e. the tawny) from an eastern one inhabiting cold, boreal ranges (i. e. the Ural). The species pattern is mirrored in other bird species, i. e. the European green woodpecker (Picus viridus) from the more northern transcontinental grey headed woodpecker (Picus canus). After retreat of the continental ice masses, the ranges more recently penetrated each other. While the life history details of the tawny and Ural owls are largely corresponding, nonetheless the species have a number of morphological differences and are largely adapted to different climates, times of activity and habitats. However, fossils of a larger and differently proportioned Strix owl than a tawny owl, identified as Strix brevis, from Germany and Hungary from before the Pleistocene (i. e. Piacenzian) and as well as diagnosed Ural owl fossils from disparate southerly deposits in Sardinia from the Early Pleistocene and in Middle Pleistocene deposits in the Pannonian Basin as well as much later during the early Holocene from far to the west in Belgium, France and Switzerland suggest a more complicated evolutionary and distributional history. A hybrid was recorded in captivity between a male Ural and a female tawny owl, which managed to produce two offspring that were intermediate in size and had a more complex song that was also shared some characteristics with both species' vocalizations. Some species in America, such as namely the barred owl, are at times thought to be so closely related as well to the extreme that the Ural and barred and spotted owls (Strix occidentalis), have been considered to potentially be part of a species complex or even within the same species. However, there is no evidence nor likelihood that the Strix owls between America and Eurasia ever formed a continuous population given their adaptation to well forested areas as well as the fact that the barred owl is more ecologically similar to the more generalized tawny owl, despite being of intermediate size between tawny and Ural owls (closer in size to the latter), and that the tawny does not range anywhere close to the boundary between North America and Russia as does the Ural. Certainly the most ambiguous aspect of the relations of Ural owl is the Père David's owl which has both historically and currently been considered either an isolated subspecies of the Ural owl or a distinct species. It is thought that the Père David's is likely a glacial relict of the mountainous forest of western China where plant and animal life often remain reminiscent of pre glacial life. Recent study has indicated that the Père David's owl is valid species based on appearance, voice, and life history differences, though genetic studies have shown a somewhat muddled diversity between races of the Ural owls species complex. It has been recognized by The Clements Checklist of Birds of the World but BirdLife International and IUCN still classify it as a subspecies of the Ural owl.

At least as many as 15 subspecies have been recognized by some authorities though some feel that there may be as few eight valid subspecies. S. u. uralensis (Pallas, 1771) This is the nominate subspecies, thought to be found in the inland part of the Russian Far East, Siberia to Yakutia and Okhotsk Coast south to Middle Volga, southern Ural, Tyumen and Yalutorovsky. The wing chord of males is whilst that of females is A small sample of males weighed while one female weighed Some females of the subspecies though may weigh as little as and, unlike the Ural owl species overall, may show some level of compliance to Bergmann's rule. S. u. yenisseensis (Buturlin, 1915) This race is found in the Central Siberian Plateau to Transbaikal and northwestern Mongolia but they are mainly recorded as winter vagrants in the latter two areas. The wing chord of males is while in females it is Tail length is from This race is fairly similar to the nominate subspecies but is typically a little less whitish overall and typically overall much smaller than it as well as most European Ural owls. The distribution in Germany is particularly nebulous (and perhaps aided by reintroductions branching from the well known Bavarian population), with evidence of Ural owls apparently residing (and possibly nesting) considerably away from currently known haunts in Egge far to the west and mysteriously turning up rather to the north in Harz and Lüneburg Heath. In eastern Europe, the species is found in eastern Croatia, Bosnia and Herzegovina, western Serbia, montane west central Bulgaria, montane central Romania, much of Slovakia, southwestern Ukraine, southern and eastern Lithuania, northern Belarus, eastern Latvia and much of Estonia. The species' distribution is continuous to the Russian Far East to as far as Okhotsk Coast and Magadan, Khabarovsk Krai and Sakhalin. The Ural owl is also distributed through all five of the main islands of Japan (i. e. only absent from Okinawa/Ryukyu Islands to the south).

Ural owls tend to occur in mature but not too dense primary forest, which can variously be in coniferous, mixed or deciduous areas. Normally, they prefer to be close to an opening. These are often compromised by forest bogs with wet ground underfoot is overgrown by a mixture of spruce, alder and/or birch or by damp heathland with scattered trees. Forest predominant in beech were also seemingly preferred by the reintroduced Ural owls in Bavarian Forest, again with old growth preferred with plentiful sun exposure. Bavarian owls occurred in areas that were also often rich in large mammals since their preference for access to parts of the forest with broken trees and openings often coincided. Further north in Latvia, forests inhabited were usually far older than was prevalent in the regional environment, usually with a preference for forest areas with trees at least 80 years old. Finnish populations apparently most often occur in spruce dominated forest, usually having discreetly segregated forest preferences apart from sympatric species of owls except for the boreal owl, which also preferred spruce areas but occurred more regularly when the dominant Ural owls are scarce. In the taiga of western Finland, it was found that biodiversity was consistently higher in the vicinity of Ural owl nests than outside these vicinities, rendering the Ural owl as perhaps a “keystone species” for the local ecosystem. Riverine forests with birch and poplar are often utilized in the taiga as well as spruce or fir forests (montane taiga) in the Ussuri river area. Changes in nesting habits due to the erection of nest boxes has almost allowed Ural owls to nest unusually close to human habitations in the western part of the range, especially in Finland. At least one Ural owl was recorded to habituate the city of Ljubljana in Slovenia but there was no evidence it was able to breed or establish a territory given the limited nature of woodlands in the vicinity.

The Ural owl is often considered nocturnal with peaks of activity at dusk and just before dawn. However, taken as a whole and since it mainly lives the taiga zone where very long summer days are the norm against extensive dark during the winter, Ural owls are not infrequently fully active during daylight hours during the warmer months, while brooding young. Presumably during winter, they are mostly active during the night. Thus, the species may be more correctly classified as cathemeral as is much of their main prey. The wide range of activity times, and partial adaption to daytime activity, is further indicated by the relatively small eyes that the species possesses. Territories are generally maintained with songs, most often uttered by the male of the resident pair. This is quite the norm for owls in almost every part of the world. As for movements, as opposed to the sedentary adults, immatures may wander distances of up to about An occasional individual may wander straggle even further and remain for some time in a wintering area. Siberian population shows somewhat southward movements in severe winters, as the number of prey animals plummets and the owls themselves face risk of freezing. In a compilation study of the diet in three European study areas and four different years found that the mean prey body mass taken per nest was estimated to vary from with an average estimated at In Slovakia, in addition to glades and meadows near tall forests, Ural owls have been somewhat acclimated to hunting in open areas that are human sourced, including areas of forest fragmentation and even agricultural areas and small towns and villages if they are adjacent to mature forest patches. However, in Scandinavia, Ural owls were reported to hunt more like goshawks rather than the more still hunting tawny owls, with a perch hunting method wherein they fly in brief spurts from perch to perch, with the flights meant to be inconspicuous until prey is detected. Ural owls are not known to attack prey from active flight, instead nearly always dropping down on it directly from its perch. In Japan, experimental studies of semi captive Ural owls were undertaken to observe how the owls select which areas to hunt in and which prey to select. When experimentally exposed to patches where prey was present and patches where prey was not present, Ural owls would forage in both but would seem to learn which patches were more likely to have food and subsequently forage more extensively around them. When the same biologists observed the foraging patterns on field mice and also voles, they similarly learned and showed a preference for the patches that held larger species over smaller ones. On evidence, though prey selection is largely opportunistic, rodents at risk of starvation in the Japanese studies were more likely to risk foraging in relatively open spots of the ground, so therefore would be preferentially selected by the Ural owls. Based on the Japanese studies, Ural owls seem to be able to improve their resource utilization patterns as they accumulate experience within their environment. Different studies in Japan showed that the Ural owls are capable of hunting prey that is hiding in shallow snow or near the snow's surface during winter but voles hiding in the subnivean zone, ephemeral tunnels made under deep snow by the voles, are largely inaccessible to these owls. Surplus food may be stored at the nest or at nearby depots.

Voles, small to medium sized rodents with characteristically short tails, are often considered the most significant portion of the diet in almost every part of the distribution. Generally, in several parts to the west of their range, the Ural owl is associated with two vole prey species in particular, field voles (Microtus agrestis) and bank voles (Myodes glareolus). These voles tend to be solitary and fairly widely dispersed but habituate to favorable habitats for the Ural owls, such as the opener margins of extensive forested areas, and can quite numerous when vole populations peak. Per study in Finland, Ural owls took field and bank voles that averaged larger than the average weight of those captured in the field by biologist, i. e. the weight of those caught by owls was estimated at for field voles vs for bank voles, while those caught by biologists averaged for fields vs for banks. 56% of the field voles those caught by Ural owls were reproductively active, while 44% of bank voles were active as such. More socially inclined and concentrated voles such as common voles (Microtus arvalis) tend to occur in more extensive open areas so forest dwelling owls such as the Ural tend hunt them relatively scarcely, but only relative to many other predators. The largest known dietary study to date occurred in Finland, with 5995 prey items examined across several study years. According to this data, a much larger vole was preferred in the diet where available, the European water vole (Arvicola amphibius). With an estimated mean weight of , the water vole constituted an estimated 22.15% of the prey by number and 52.2% of the biomass, against 19.5% by number and 18% of the biomass being made up by field voles. The average estimated prey weight overall within the study was estimated at Another, albeit smaller, central Finnish study showed field voles leading by number over water voles, 42.7% against 33.9%, among 1739 prey items respectively, but with the two species constituting 17.4% and 69.1% of the prey biomass. Southern Finnish studies showed sharp shifts in the import of vole prey due to their population cycles. In southern Finland, of 3351 prey items in a peak vole year, 58.43% by number and 42.8% by biomass of the prey was made of by field voles, followed by bank vole at 12.41% by number (but only 5.73% by biomass) and water voles at 22.24% by biomass (but only 10.1% by number). In the same study area during a poor vole year, amongst 860 prey items, voles trailed other prey such as birds and shrews by number, but water voles were taken more or less in the same numbers here as in the peak vole years. Similar dietary habits were found for Ural owls in Sweden, in 2309 prey items, water voles made up 33.1% of prey by number and 60% of the biomass, field voles composed 30.8% by number and 14.5% of the biomass and bank voles made up 11.8% of the prey by number and 3.3% of the biomass. Camera traps recording captured 187 prey items for Ural owls in 5 nests in Värmland County, Sweden found that voles were secondary in delivery rates to common shrew (Sorex araneus) and various birds with the small size of such prey requiring frequent deliveries although this was offset with fair numbers of young hares apparently available to these owls. As the Ural owl ranges south, prey populations tend to become slightly less cyclical but also apparent access to large prey such as water vole appears to be reduced. In the relatively northerly Latvia, of 2615 prey items, voles constituted just over half the diet and the prey base was relatively diverse. For Latvian owls, the main prey species were bank vole (at 18.09% by number, 9.2% by biomass), field vole (17.13% by number, 13.85% by biomass) thence European mole (Talpa europaea) (9.83% by number, 12.3% biomass), the latter at a mature mass of about ). In the Beskids of southwestern Poland, the mean prey mass of 1039 prey items was a quite low with the main prey species being the bank vole, making up an average of 27.7% of prey by number and 25% of the biomass (average estimated weight ), common voles constituting on average 24.9% of the prey by number and 25.8% of biomass (average estimated weight ), yellow necked mouse (Apodemus flavicollis) on average 15.73% of prey number and 17.4% of biomass (average estimated weight ) and European pine vole (Microtus subterraneus) at an average of 8.9% of the prey numbers and 5.8% biomass (average estimated weight ). Outside of voles and field mice, other prey appears to be largely negligible in the Polish Beskids. In Slovakia, amongst 2134 prey items, the main prey species were the yellow necked mouse (21.8%), common vole (18.3%), bank vole (14.3%), striped field mouse (Apodemus agrarius) (4.9%) and European pine vole (4.7%). Diets of the Ural owls towards the southeast part of the Europe range have mainly been recorded in Slovenia. The broadest study found that of 1268 prey items, 45.9% of the diet was voles, particularly the bank vole (38.1% by number, 26.24% by biomass), with another 34.2% made up of by Apodemus species (as well as 28.2% of the biomass) and a large portion of dormice, especially the large edible dormouse (Glis glis), at 6% by number and 25.5% by biomass. More locally in a smaller block within Slovenia, up to 58.8% by number and 94.4% by biomass in the Ural owl's diet is compromised by the edible dormouse, whose adult body mass can vary from
Further east and out of Europe, the general reliance on small rodents for Ural owls is fairly consistent. In one of the most westerly studies, from Mordovia, Russia, of 426 prey items the main prey species were common voles (41.8%), bank voles (31.4%), tundra voles (Microtus oeconomus) (5.9%) and Ural field mouse (Apodemus uralensis) (3.1%). At five study sites in the Ural mountains region, among 870 prey items, 75.2% were mammals. 29.54% of the diet in the Urals were bank vole, 16.55% were common vole, 5.52% were wood mouse (Apodemus sylvaticus) and 4.83% were unidentified Myodes voles. Further east, the general reliance on Myodes, also known collectively as red backed voles, outside of the far ranging bank vole seems to increase somewhat. Much further east in the Pacific coastal Primorsky Krai, 1163 total prey items were examined. Here rodents of similar character, though largely of different species, were largely taken by Ural owls, such as the northern red backed vole (Myodes rutilus) (39.2% by number), reed vole (Microtus fortis) (24.24%), Apodemus sp. (9.7%), Korean field mouse (Apodemus peninsulae) (3.52%). In the isles of Japan, the smallish local races of Ural owls seem to assume the dietary generalist Strix owl ecological niche to some extent, in a similar way the tawny owl does to the west, however the primary portions of its diet are still assumed by many of the same prey genera taken elsewhere. In the Yatsugatake Mountains, 1026 small mammals were identified at 17 Ural owl nest of which Apodemus species compromised 71%, followed by voles, at 24%, and Japanese shrew mole (Urotrichus talpoides), at 5%. Shrews of nearly 20 species are taken more or less throughout the Ural owl's range. Although not significant typically in the prey mass for the owls, the taking of shrews may allow the owls to stave off hunger. The smallest mammal and vertebrate prey known to be taken by Ural owls is the Eurasian least shrew (Sorex minutissimus), which has a median adult body mass of about Among these are a few species of squirrel, most of which weigh more than as adults, in Europe exclusively the far ranging red squirrel (Sciurus vulgaris), as well as rats, especially the brown rat (Rattus norvegicus) which made up nearly 20% of the diet in a Hokkaido study. One large mammalian prey widely associated with Ural owls are hares, though they seldom occur in substantial numbers in the diet, they appear to be opportunistically taken in most parts of the range. As much as nearly 25% of their biomass may be hares and hares are the largest known prey to be taken by Ural owls. Japanese hares (Lepus brachyurus) may also be taken in Japan as well.

The second most important prey group behind mammals (albeit considerably behind) is birds. Birds are also the most diverse prey group in the Ural owl's diet, with well over 100 avian prey species recorded. The hunting of birds by the Ural owl seems almost entirely based on opportunity as there is little evidence that they track down birds of any particular type, just merely upon the chance of encounter or detection. Other than pigeons and doves, non passerine bird prey are usually taken relatively infrequently, although some prey families such as gamebirds and woodpeckers are also quite widely taken. An unusual preference for relatively large bird prey was reported in study from the Urals where the most frequently identified avian prey species were the hazel grouse (Bonasa bonasia) and the hooded crow (Corvus cornix). Outside of aforementioned families other infrequently taken bird prey has included cuckoos, nightjars, sandpipers, terns, rollers and hoopoes. In the small Swedish study from Värmland County, an exceptional 12.2% of delivered prey was common frogs (Rana temporaria). In Primorsky Krai, Ural owls were further recorded as preying upon Daurian crayfish (Cambaroides dauricus). The diets were largely similar between tawny and Ural owls as well in the Bavarian Forest of Germany but the tawny species took proportionately fewer field voles and more insects, and was estimated to take prey weighing on average 43% less than that taken by Ural owls. In Slovenia, Ural owls actually responded more consistently to recorded calls of tawny owls (40% of call exposures causing a vocal or physical response) than to recordings of calls of their own species (34% of call exposures eliciting a response). However, cases of interspecific killing between the species are fairly infrequent, and recent study indicates that the tawny owl's relatively checkered distribution in northerly areas such as Fennoscandia is not likely due to this competition but rather due to the regional habitat type favoring the Ural owl. The tawny owl is not as well suited to taiga habitats as is the Ural species and locally are less suited to alternate nest sites (i. e. nesting in areas lacking tree cavities or nest boxes, whereas the Ural can locally also use old bird nests and tree stumps). Warming average temperatures in Fennoscandia have appeared to effect many owl species negatively due to the limiting nature on vole cycles, but the tawny owl, being confined to the south, has had the most decreased effect locally due to the lowering vole numbers (and despite their general ability to adapt to different prey) while the Ural owl, in central Finland at least, is not yet showing as drastic a negative effect due to this. Similarly, the tawny owl and Ural owl are largely segregated by altitudinal range and habitat in eastern Europe (i. e. the Carpathian mountains) and Poland, with little evidence that this is due to interspecific competition or predation but rather the suitably of the montane habitats. Here the tawny owl tends to occur at lower elevations while the Ural owl occupies the foothill forests at higher elevations. Generally, despite higher densities of the Ural in some mountainous parts of central and eastern Europe, the tawny owl is far more numerous in all countries of that region than the Ural owl. In Slovakia, 13.3% of Ural owl territories overlapped with those of tawny owls, a relatively low overlap given the overall environment. Despite the Ural owl's presumed dominance, in Slovenia, a tawny owl was observed to fiercely attack a Ural owl until it left the vicinity, though it is not clear whether this was a territorial encounter or antipredator mobbing. More locally, in Finland, the Ural owl took proportionately more European water voles, overall birds and amphibians than did the eagle owls but took far fewer gamebirds. Being smaller than the great grey owl and Eurasian eagle owl, it is projected that the Ural owl can live off of less food overall than them. It is estimated that over a 6 month period, a Ural owl needs about of food while a great grey owl needs about and an eagle owl needs about A similar relationship has been detected between the Ural owl and the Eurasian pygmy owl (Glaucidium passerinum), a species less than half the size of a boreal owl. Other predators known to prey upon Ural owls have included golden eagles (Aquila chrysaetos), eastern imperial eagle (Aquila heliaca), mountain hawk eagle (Nisaetus nipalensis) and Eurasian lynx (Lynx lynx) as well as diurnal raptors that are only slightly larger, including the northern goshawk and lesser spotted eagle (Clanga pomarina). In most cases mentioned above, the age of the Ural owl taken by the predators are not usually specified (although any of the first three large eagles are certainly capable of striking down Ural owls potentially of any age). In some cases, goshawks have been known to kill parent Ural owls apparently entirely out of competition (despite different main food sources) and lay their eggs on a nest still containing the owls' eggs. In Primorsky Krai, Asian badgers (Meles leucurus) and raccoon dogs (Nyctereutes procyonoides) are mentioned as potential or likely predators of Ural owls nests as well. Although predation events upon Ural owls are widely reported, the relative number of incidents of such are very low and singular. South of the Arctic, it can be considered to rival the great grey owl as the owl species that is second least vulnerable to predation, behind the apex predator eagle owls. In addition, Ural owls are known to have successfully have chased off actively nesting goshawks as well as European honey buzzards (Pernis apivorus), common buzzards (Buteo buteo) and black kites (Milvus migrans) in order to claim the nests for themselves. Despite their potential predation on smaller mesopredators, when nest boxes for European pied flycatchers (Ficedula hypoleuca) were experimentally placed in the area of Ural owl nests, productivity lowered, and it is possibly because mesopredators were often attracted to the corresponding food base of the owls. On the contrary, experimental ground nests put out by researchers with random poultry eggs in central Finland were shown to be incidentally protected by the fierce presence of Ural Owls. In the Finnish ground placed almost directly under the Ural nest none at all were preyed upon, while in those placed away, 8.3% were predated, and those within experienced an average predation rate of 58.3%. At a great distance, at all ground nests were predated.

The Ural owl generally pairs for life and maintains a territory for several years. Mate retention in Fennoscandia was found to have averaged 98–100% in males and 90 95% in females, making it amongst the most monogamous birds of prey of any order (or at least well studied bird of prey species). Territories of Ural owls are on average about 3 times larger than those of tawny owls. In Sweden, about 3000 pairs of Urals are found in an area. In 2016, it was estimated that Slovenia holds 400 700 pairs. Survey of the species in Silesian Beskids was done, where the population may represent a recent population expansion. With as many as three breeding attempts, Density was estimated at 0.6 0.9 pairs per , 3 10 times lower than other nearby ranges in eastern Europe like the Low Beskids and Bieszczady Mountains. A low density population was found for Pieniny National Park, Poland with 0.9 1.3 per The average density in the Polish Kraków Częstochowa Upland was 1 pair per In the northern part of Moravia, Czech Republic, 3 5 pairs were recorded around the turn of the 21st century, an almost certain population increase. A population increase noted in the Roztocze area of the Ukraine, despite the forest being mixed rather than the subspecies' preferred beech dominant, now up to 1.7 pairs per Where nest boxes were put up for Ural owls in Samara Oblast showed the owls taking up residence in boxes at an average distance of ; against which the average distance of all installed boxes was .

Potential nesting sites include large natural holes in trees, cavities left by large branch that have broken off, hollow trunks where canopies have been broken off (or "chimney stacks"), fissures or holes in cliffs or between rocks and holes in buildings. Nest can be in the vicinity of small towns, as was recorded in southern Sakhalin, so long as appropriate habitat and prey access is available in the region. In one case in Norway, a Ural owl utilized a hole in a common aspen (Populus tremula) in the same tree where common mergansers (Mergus merganser) were using a different hole. In several parts of their range they may make use of nest boxes, with the trend of nest box placement beginning and being perhaps most persistently used in Fennoscandia. Incidental benefit has been shown for several beetle species and sometimes other insects that have come nest in the substrate of Ural owl nest boxes, even in areas where the invertebrates are rare or endangered. Of 250 nests recorded over nearly a century in Finland, stumps accounted for most (34.3%), followed by bird nests (28.5%), nest boxes (23.1%), tree holes (11.35%) and lower numbers on ground or on rock face or building. 53% of Finnish stumps were in spruce and 38% in aspens, from high with an average of Stumps were preferred in the northern and central part of Finland. 67% of Finnish cavity nests were broken off branches of birches, though black woodpecker (Dryocopus martius) holes that had rotted and expanded were also sometimes used, with the cavity nests height from Cavities were preferred in the southern part of Finland. Nest boxes increased in importance after 1960 and, by 1969, 50% of recorded nest usage in all Finland was in nest boxes. In Slovenia, 56.2% of recorded nests were in tree holes, with about a further 20% on stumps, at over the ground (on an average ). Less often Slovenian owls nests in old bird of prey nests (16 19%). Even in peak vole years some parts may be unable to breed due to lack of acceptable nest sites. However, in Hedmark, Norway, the placing of 80 nest boxes did not increase the country's Ural owl population, with only 4 of the boxes used. The lack of success for Norwegian populations is thus not seemingly due to a lack of nesting sites but is theorized to be more so correlated with a poor prey population for them. Prior studies, in central and eastern Norway, somewhat more westerly into Norway than previously thought but not an extensive range, with the clutch size being smaller, at a mean of 2.85, within Scandinavia compared to 2.93 in Sweden, 3 in southern Finland and 3.92 in northern Finland.

The clutch size is typically 3 4 (rarely from as few as 1 to as many as 6), with the eggs being pure white and quite rounded. Mean clutch size in Slovenia is about 3.3. Clutch size in a small sample from Nizhny Novgorod Russia was found to average 3.6. The clutch size average in nest boxes of Samara Oblast was 2.4. The eggs are laid directly to bottom of nesting surface in roughly 2 day intervals. Incubation lasts for 28 to 35 days and averages about 6 days longer than the incubation period of the tawny owl. The hatchlings break at concurrent time lapses as the eggs are laid (about 2 days), the females staying by until fledging. The same typical age (3–4 years) was detected in central Sweden, despite the females often being on territory within their first year. On the contrary, a Finnish study found that for Ural owls of both sexes, it was estimated that the mean starting age for breeding is 2.9 years, with an average breeding life expectancy of 3.3 years. Furthermore, females that started breeding at 2 or 3 were shown in Finland to have higher reproductive “fitness” than females who started breeding at 4 or older. Females laid eggs in Finland an average of 2.7 times in their life and produced an average of 6.7 fledglings over their reproductive lifetime (with the most productive females producing up to 33 fledglings). Brooding activity peaks, with typically 9 14 daily visits, in Finnish studies in the late evening during spring and summer while tending to young, with a weaker peak activity time in the early morning, both timed to peak prey activity times. Due to her attacks, the predation rate on Ural owl is often exceptionally low.

Broods with more than three chicks sometimes experience siblicide per study in southern Finland, but instances of siblicide are rare otherwise. Hatchability in south Finland averages 87% across all years. Breeding success in southern Finland was also driven by the mother Ural owl's age, with 3 5 year old females being less productive than those that were 6 to 9 years old, and that older females, of more than 10 years old, tended to lay larger and more rounded eggs. Males were mildly more numerous in Finland among fledged young (56%) but survivorship of the two genders were essentially equal and body mass in both sexes averaged about 6% more in good vole years. Studies of 274 Finnish adult females found that 18% of them produced about half of the fledglings. Findings showed that parent Ural owls, particularly the adult female, are able to adjust their breeding cycle to maximize survivorship of their young well given the experience accrued during their relatively long lifespan, and are relatively successful at mitigating issues such as parasitism and infestations in nest boxes if they are being used. Post dispersal young from Vienna Woods in Austria were radio tracked and showed a mean dispersal distance of from release site and were shown to experience about a 23% mortality rate. In Estonia, managed forest almost invariably have fewer Ural owls than undisturbed forest has because of reduction of snags and other natural cavities to use. However, the general trends are positive for most European Ural owl populations. Several population increase and expansions have been detected in central and eastern Europe for Ural owls in recent history, in sync with other owls considered boreal species (i. e. great grey, boreal, Eurasian pygmy). Previous records indicated staple populations in the 1980s for Ural owls in the western Carpathian mountains (estimated at 1000 pairs) and northern Belarus (at 50 100 pairs). By the 1990s, the number had grown to 1000 1500 pairs in the western Carpathians and to 220 1350 pairs in northern Belarus. By 2005, the numbers were up to 3500 pairs in Carpathians and a drastic increase to 2700 4300 pairs in Belarus. In the Czech Republic, partially due to deliberate reintroductions, the numbers went from 1 5 pairs in 1985–89 to 25 40 pairs by 2001–2003. In selected plots of southeastern Poland, Belarus and Latvia, densities went from 1 2 pairs per to 10 pairs per In these three countries, northern population now much higher density than southern ones, i. e. 5–8.1 pairs per in north to 3.1 3.6 pairs per in the south. A range expansion of Ural owls was detected in western Ukraine (in the general region of Roztochya Biosphere Reserve and Yavorivskyi National Park). in 2005 07 up to 1.7 2 pair per whereas in the past (i. e. to the 1990s) the species was a rare vagrant to this area. This density of this Ukrainian population is higher than seemingly most in Scandinavia and Belarus but lower than in southwestern Poland and Slovenia; while whether this represents a population increase or merely a population shift is unknown nor its relation to forestry. In some parts of Slovakia, such as Slanské vrchy, Vihorlat and the Ondavská Highlands the density of pairs may be up to a pair per square kilometer, perhaps the highest known specieswide. In every regard but number of nestlings that were ringed (in which it also trails the Eurasian pygmy), it has been observed the Ural is the 2nd commonest detected breeding owl after the boreal owl in Finland with 2545 territories found, 1786 nests observed and 4722 nestlings ringed. An increase of the population was found in the Moscow region where tall stands remained despite the rather developed environment nearby. Occasionally, Ural owls are vulnerable to flying into manmade objects. In most parts of the range, they are less vulnerable than many other large birds of prey (in part because of their preference for remote forests) but certainly a few are likely to be claimed as such. Many such mortalities are due to wire collisions and electrocutions, which are likely increase especially as populations expand and move into areas closer to human habitations. Other collision kills, such as with glass buildings and, widely, with various automobiles, may too potentially be on the increase. Though historically subject to some degree of persecution, Ural owls were spared from the worst of it perhaps by nesting in remote forests and possibly by being generally less predatory to small domestic fowl, game animals and the like than large raptorial birds like Eurasian eagle owls, golden eagles and northern goshawks, all of which were badly persecuted and thusly reduced. Like other wild birds, Ural owls may be vulnerable to some degree of mortality due to diseases and infections but these are unlikely to compromise overall populations. 71.4% of 14 wild Ural owls in Japan had blood parasites while a smaller but still present number of Acanthocephala and roundworms were detected in known European data. Many Japanese Ural owls were also found to be vulnerable to biting lice.

Species reintroductions have been undertaken in some different parts of Europe. By far the best documented Ural owl reintroduction was in the Bohemian forest, which ranges between the countries and regions of Bavaria in Germany, the Czech Republic and upper Austria. Previously the species was extinct here by 1926 (by 1910 on the Austrian side). Established of captive breeding stock occurred between 1972 and 2005 (with origins from 7 different countries and a mixture of the two main European subspecies). For this breeding program, 212 young Ural owls were originally released. During the study, experimental introductions were made to tawny owl nests, although this potentially exposed them to risk of hybridization. Otherwise, parentage consisted of relatively newly established Ural owls. Both tawny and Ural owls were shown to be able to successfully raise the young Ural broods. Food was also offered to pairs at nearby release pens and 60 nest boxes erected to compensate for lack of nest sites, especially in areas of secondary forest. 33 Ural owls were recovered dead, while an additional 4 were weakened or injured to the state of being unable to continue to live in the wild. Most of the mortality was due to electrocution or were hit by cars but a few were illegally shot. The first wild breeding of a Ural pair in the Bohemian forest occurred in 1985 but the first successful breeding was not until 1989 (with the pair having producing 4 offspring). Between 1981 and 2005 a total of 49 broods were recorded, 31 of which were successful with 59 young produced (avg 1.3 per all attempts, 1.9 per successful pair). No fewer than 6 pairs (possibly 5 10 breeding pairs) were established by the end of study, with the carrying capacity within the forest estimated at 10 pairs. For a self sustaining breeding population, it was felt that at least 30 pairs are necessary in the general area within connected corridors to the Bohemian forest. Therefore, 87 birds were introduced into nearby Sumava National Park between 1995 and 2006, an estimated 2 3 breeding pairs have established there now. A still uncertain pilot program in Mühlviertel, Austria may or may not have produced a pair as well. In 2001, among two reintroduction attempts in Austria, both failed. All told from the entire Bavarian reintroduction, it was said that the owls producing a total of 204 offspring between 1972 and 2014, although many of these may not have survived. More successful than the Austrian part of the Bavarian forest reintroductions was the reintroduction elsewhere in Austria, namely the Vienna Woods. In this project, 67 young owls were released between 2009 and 2013. A nesting box network of 127 boxes were set out to be utilized and one of Europe's largest stands of beech trees was present. In the Vienna Woods, the survival rate was high at about 70.5%. By 2011–2012, 10 pairs attempted to nest, establishing home ranges averaging about and produced 3.1 fledglings per successful pair.