Tawny owl bird. Tawny Owl. Lifestyle and habitat of the tawny owl bird Appearance and distribution
Order – Owls (Strigiformes)
Family – Owls (Strigidae)
Genus – Tawny Owl (Strix)
Great Gray Owl(Strix nebulosa)
The great gray owl is a protected species (CITES Convention). It is protected by local and regional legislation of those countries in which the species lives. In Russia, this owl is included in the Red Books of many regions and republics.
Appearance:
The plumage of adult and young birds is generally light brown, smoky gray, with numerous streaks. The back is gray or buffy and has longitudinal brown spots. The crown and back of the head have an ocher tint and a dark brown longitudinal and transverse pattern. The same pattern is noticeable on the shoulder and coverts of the wings, where, in addition to it, the light outer webs of the feathers sometimes form clear transverse bands. The chest, belly and sides are light gray, with sparse irregular brown spotting, sometimes forming intermittent longitudinal rows. The flight feathers are dark brown, with light transverse stripes, especially developed on the inner webs. The facial disc is whitish, with sharp dark brown concentric circles. The inner and partially lower edges of the facial disc are framed by almost white feathers, which create a pattern in the form of two crescents touching the backs. The throat is black-brown, in the form of a wedge (“beard”). The iris of the eyes of sexually mature individuals is bright lemon-yellow, less often orange-yellow. The beak is light, yellowish. The claws are blackish.
Newly hatched chicks are almost entirely covered with thick, light, almost white down. The skin on the body is pinkish-brown, on the paws it is pale yellowish, the claws are dark steel, the beak is brownish-gray, pinkish at the base, the iris of the eyes is brownish-violet.
Weight of an adult bird: 660-1900 g, body length reaches 80 cm, wingspan - 1.5 m. Females are much larger than males.
Area:
Taiga inhabitant and inhabitant of mountain forests. It can be found all over the Kola Peninsula to the mountainous areas of Primorye. The northern border of the habitat is marked by tall forests and continues south to the Baltic countries, Germany, and the center of European Russia. Taiga climate of Siberia, forests of Transbaikalia, harsh conditions This owl also likes Sakhalin. However, it can settle further south, for example, in Mongolia. And in winter it sometimes flies into the central zone. Another continent where you can find this owl is North America.
If a great gray owl chooses taiga plantations, it must be with high humidity - swampy ones, as well as alternating with open areas - burnt areas and wastelands.
Nutrition:
The food of great gray owls is standard for most owls - small rodents. But sometimes the owl comes across squirrels or small birds, and sometimes a larger animal, for example, a chipmunk, sable, rabbit, weasel or hare, becomes its victim. Amphibians, snakes, and sometimes even fish do not escape the claws of a feathered predator.
It hunts early in the morning or in the evening, but can also hunt at night and even during the day, especially in winter. It hunts most often from ambush, sitting in a tree and carefully observing, and most importantly, listening to what is happening in the nearest clearing, swamp or clearing. For the great gray owl to hunt, it is necessary to have open, forest-free areas. The main “weapons” when hunting are excellent hearing and claws. An owl can detect the presence of prey by hearing, even if it is not on the surface, but at a depth of up to 30 cm under the snow or underground. Then she flies from the branch and grabs her prey with lightning speed with her claws.
Reproduction:
Great gray owls have permanent pairs and form for life.
Mating games among gray owls begin in the spring and are marked by loud, unique trills of the males. Courtship is expressed in mutual feeding and cleaning of plumage, however, most often the male brings food and treats the female. Then the male chooses a territory and notifies the female about it. She examines several areas before settling on the most suitable one. Usually they use other people's nests - buzzards, goshawks or ravens, located high in the trees. Unlike other owls, great gray owls renovate and improve an old alien nest. They use pine needles, deer hair, moss and pieces of bark as fresh bedding.
There are 2 to 4 white eggs in the clutch. The female incubates, sits on the eggs very firmly, and her wings and tail are raised high, so that the bird resembles a brooding hen. Incubation begins with the first egg and lasts 28-30 days.
The male hunts most of the time and feeds first only the female, and then the chicks. The hatched chicks are covered in white down and, unlike other owls, develop rather slowly. At first, the female tears up the prey she brought and feeds the chicks, and then they learn to do this themselves, and then the female also begins to hunt. Adult gray owls at the nest are very aggressive, they boldly attack and strike with their claws, trying to hit even humans and bears on the head.
The chicks leave the nest at the age of 3-4 weeks and begin to learn to fly. They fledge completely after 8 weeks, but remain at the nest for several months. Their parents continue to feed and protect them.
Our pets:
It is very difficult to distinguish between male and female Great Gray Owls, which is why our parents are simply named Laura and Lorik. These two owls looked closely at each other for a very long time before starting a family. And we didn’t observe the notorious trills, because... this couple is very “shy”. But they are very attentive and loving parents. Laura and Lorik have raised more than one brood and our Great Gray Owls have graced more than one zoo.
Interesting fact:
Great Gray Owl Can Regulate Temperature own body, loosening or, conversely, compressing the dense plumage.
There are cases of cannibalism among Great Gray Owl chicks. Chicks that are older and stronger are capable of eating their younger and weaker brothers due to lack of food.
The great gray owl is a large, large-headed gray owl with numerous dark and light spots. Of all the forest owls, it is second in size only to the eagle owl. In addition to the difference in size, it differs from the great owl in relatively small yellow eyes, clear concentric circles on the facial disc, and the presence of a dense black spot ("beard") under the beak. In general, the great owl is somewhat larger, more big-headed and darker. The female is larger (more dense) than the male, and has the same color. Juveniles in the second plumage are generally darker and browner than adults, have dark spots on the facial disc, and yellow eyes. Elements of this plumage persist until autumn, and in the latest chicks - until November. In the first adult outfit they look like adults. Contact characteristics for identifying young ones in the first winter: tail feathers are narrow (45-55, rarely - 60 mm, in adults - 55-70) and with pointed tips (rounded in adults), on the tips - with a narrow white edge, which in the spring it can completely wear out, especially on the central tails (in adults the tops of the tails are gray). In first-year birds, the flight feathers are worn approximately equally; in the spring, their gradual change begins, and from that time on they vary in wear. Weight of males 600-1100, females - 700-1900 g, length 63-70, wing of males 43.0-46.6, females - 44.1-46.7, wingspan 130-158 cm.
Voice.
The current calls of the male are similar in the nature of the sound to the calls of the great owl; they are dull, low, hooting sounds, but the structure of the song is different. It consists of about a dozen monosyllabic cries: "gu-gu-gu...", which at the beginning of the song are pronounced at intervals of about 0.5-1 seconds, then gradually fade away and become more frequent, and can almost merge at the end. At the height of the chatting, the intervals between songs can be only 5-10 seconds. The cry of a female is heard less often; it is also a low sound, but more prolonged: "guuu". When disturbed, muffled screams are uttered at the nest "huf", "heev", hiss, click their beaks, emit a plaintive undulating "uyyyyyyyyyyyyyyyy". Hungry fledglings shout hoarsely: "psiit" or "ziip". At roll call the young people shout sharply "uuuick".
Spreading.
Forests of northern and temperate latitudes of Eurasia and America. In the Ural-West Siberian region - from the northern forest-steppe to the northern taiga. In general, they are quite rare, especially west of the Urals. In the Trans-Urals and Western Siberia they are more common and in some places relatively common. Sometimes they fly into the tundra and forest-steppe. They live in the nesting area all year round.
Lifestyle.
The most favorite habitats of the great gray owl are the old taiga with swamps, meadows, burnt areas, and clearings. Nesting density and the fact of nesting strongly depend on the number of rodents. Mating cries males in the south of the range are heard already in March, in the north - in April, i.e., in fact, still in winter. They sing at dusk, at night, and often during the day.
For nesting, they use relatively open and firmly constructed nests of buzzards, goshawks and other birds of prey; they nest on high “breaks” of old trees, if there is a deepening. There are 3-7 white eggs in a clutch, usually 4-5, their dimensions are 48-60 x 39-47 mm. The female incubates, starting with the first egg and almost continuously. One egg is incubated for about 28 days. The male is located close to the nest, flying away only for prey. After hatching, the chicks are covered in white down, grayish on top, the second downy plumage is gray-brown, with an unclear transverse pattern, a dark, almost black “mask” is characteristic. The female does not fly far from the nest, even for food, and is inseparable from the small chicks. Adults are very aggressive towards predators at the nest, attacking and hitting everyone, including bears and humans, on the head and back with their claws. The chicks leave the nest at about 4 weeks of age, climbing and flying around nearby trees.
Despite their large size, gray owls catch almost exclusively small rodents; in times of famine they also hunt other animals, birds up to the size of hazel grouse, and frogs. They hunt from a perch or in a search flight. They are active mainly at dusk and at night, but sometimes during the day. When there is an abundance and availability of prey, they live sedentary, but when there is no food, they wander, flying into cities and beyond the boundaries of the nesting area.
Gray owl like rare view, listed in the Red Book Sverdlovsk region and Saldinsky region.
When describing the bird species of the Saldinsky region, the book “Birds of the Urals, the Urals and Western Siberia” was taken as a basis. Reference guide. Author V.K. Ryabitsev - Ekaterinburg. Ural University Publishing House 2001
General characteristics and field characteristics
Of all the owls, the great gray owl is the largest. Its wingspan is slightly less than 1.5 m. The impression of considerable size is enhanced by the relatively large length and width of the wings, the relatively large tail and the exceptional looseness of the plumage. In this regard, given the generally brown coloration of this bird, at dusk it is not difficult to confuse it even with such owls as the eagle owl and the fish owl, although the latter are undoubtedly larger, more powerful and more than twice as heavy.
In addition to its large size, in the field the great gray owl is distinguished by its obvious large head. Through binoculars you can also see an exceptionally perfect facial disc, mottled with dark brown concentric stripes, which is not observed in our other owls. In addition, light areas are clearly visible on its facial disc - crescents radiating from its center, and a dark wedge of feathers under the beak, which gives this bird its name. Unlike all other species of owls, the irises of the great gray owl's eyes are light yellow. These eyes, in combination with the facial disc, give the owl not a “wise” look, but rather a “stupidly surprised” look.
The flight is easy, the flapping of the wings is leisurely, as if lazy. Despite its large size, the bird flies confidently in the forest, since with its wings partially open it flies high speed capable of rushing between trunks, avoiding collision with them. However, the great gray owl is characterized by a slow, maneuverable, often gliding flight from one perch to another or a similar search drift over the ground itself. During such a flight, even in thick twilight, light spots are noticeable on the underside of the wing at the very bend of the wrist, as if glowing in the dark. There is even an opinion (Wahlstedt, 1969) that these spots have a signaling value for recognizing each other by members of the species.
This owl is active mainly at dusk, although it often hunts during the day. Lives in forests taiga type, often on the border with extensive raised moss bogs, near deciduous pigweeds, old burnt areas and clearings.
Description
Coloring. The final plumage of adult birds is generally light brown, smoky gray, with numerous streaks. The latter are formed due to both lighter and darker colors of individual feathers and their parts. The dorsal side appears grayish or buffy and has longitudinal brown spots. The crown and back of the head have an ocher tint and a dark brown longitudinal and transverse pattern. The same pattern is noticeable on the shoulder and coverts of the wings, where, in addition to it, the light outer webs of the feathers sometimes form clear transverse bands. The chest, belly and sides are light gray, with sparse irregular brown spotting, sometimes forming intermittent longitudinal rows. The flight feathers are dark brown, with light transverse stripes, especially developed on the inner webs. The tail ones are brown, with light whitish streaks, creating an irregular, “marbled” pattern. The facial disc is whitish, with sharp dark brown concentric circles. The inner and partially lower edges of the disc are framed by almost white feathers, which create a pattern in the form of two crescents touching their backs. The mandible (throat) is black and brown, in the form of a wedge (“beard”).
The iris of the eyes in mature individuals is bright lemon-yellow, less often orange-yellow. The beak is light, yellowish. The claws are blackish.
Newly hatched chicks are almost entirely covered with thick, light, almost white down. Its color has a noticeable gray tint, mainly on the back. The skin on the body is pinkish-brown, on the paws it is pale yellowish, the claws are dark steel, the beak is brownish-gray, pinkish at the base, the iris of the eyes is brownish-violet.
The mesoptile on the upper and lower sides of the body is more or less the same - brownish, with a light transverse pattern, forming a characteristic frequent stripe, especially noticeable on the chest and sides. In this plumage, the future facial disc, apart from a small dark spot between the beak and the eye, is light gray. Subsequently, this area, even in half-fledged chicks, is covered with dark brown feathers, forming a kind of mask, the contrast of which increases due to the significantly lighter feathers on its periphery. The flight and tail feathers that appear simultaneously with the mask are practically indistinguishable in color from those in the final plumage.
The juvenile plumage, which is preserved in fledglings throughout almost the entire first year of life, is generally similar in color to the final plumage. However, with some skill, it is still possible to distinguish an old bird from a young one: the color of the plumage of first-year birds is generally darker and more saturated. During the first year, the iris of the eyes changes from brownish to light yellow. At the same time, the beak lightens, acquiring a transparent horny yellowness, the claws darken, becoming almost black.
Structure and dimensions
The great gray owl is a highly specialized myophage, which is reflected in its structure. Compared to other members of the genus, it has a slender body and a lightweight skeletal structure. Despite its large size, it has relatively weak legs, the feathered toes of which have long, but thin and slightly curved claws. This paw is excellent for catching small, mobile rodents on the ground or in the snow, but is less suitable for grasping and holding large prey, as well as birds.
The great gray owl is one of the great-headed owls of Eurasia. However, its eyes are extremely small - only 12-13 mm in diameter. This can be explained by a shift in the bird’s activity to daytime hours, which is ultimately associated with adaptation to living in northern latitudes. The great gray owl has excellent vision even in the blinding glare of the snow on a clear March day, and there are observations that in such conditions it notices a vole in the snow 200 m away.
The specificity of hunting (using mainly hearing) led to the maximum possible development of the facial disc, to the asymmetry of the auditory apparatus, which in this case involves not only the soft tissues of the auditory part of the head, but also the temporal part of the skull (Norberg, 1977). The flight of this owl is light, maneuverable and completely silent. This is achieved not only by the exceptional softness of the plumage, the relatively large size of the load-bearing surfaces, but also by the low load on them. Thus, in terms of the length and width of the wing, the gray owl among our owls is slightly inferior only to the common and fish owls. At the same time, the weight load on its wing is at least 2 times less and amounts to only 0.35 g/cm2 (Briill, 1964).
The wings are long and blunt (wing formula: IV-V-VI-III-II-I; not counting the rudimentary flight wing), their length in males (n = 38) is 405-477 mm (on average 440), in females (n = 83) - 438–483 mm (average 460). The tail length of males is 290-330 mm. The tail has a rounded shape - the central tail tails are 50 mm longer than the outer ones. Weight of males (n = 36) - 660-1110 g (average 878); females (n = 46) - 977-1900 g (average 1182) (Dementyev, 1936; Mikkola, 1983). In unfavorable years in terms of feeding, as observations in Sweden have shown (Hoglund, Lansgren, 1968), weight can decrease significantly, in some cases by 40%.
Female Great Gray Owls are significantly larger than males. This is also clearly noticeable during field observations, when birds meet in pairs, for example, at a nest. However, observing them separately, it is still difficult to determine the sex.
Shedding
Like other owls, there is a sequential change of plumage: downy - mesoptile - first annual (final in color, but combined in composition) - second annual or final, etc. In the first annual plumage, flight feathers, tail feathers and great coverts remain from the previous one wing (Dementyev, 1951). In subsequent molts, all feathers are replaced. In this case, the change of flight feathers occurs from the inner edge of each set of feathers to the outer.
The molting of adult individuals proceeds quite intensively - in May, for example, throughout the entire North-West of Russia, birds are still just preparing for it, and in October you can already meet individuals who have completely completed it. In the Krasnoyarsk Territory (Kislenko, Naumov, 1972), the height of molting in adult individuals occurs in July - the first ten days of September, when all the large and small feathers change intensively. Birds molt at similar times in the Primorsky Territory of the Far East.
Thus, the molting of great gray owls occurs mainly after the completion of nesting, during the period of raising the brood, and practically ends by the time of its disintegration.
Subspecies taxonomy
The variability is insignificant and manifests itself mainly in the degree of saturation of the plumage color. There are two subspecies: - Eurasian and nominative North American S. n. nebulosa (2). The latter is distinguished by a relatively dark overall color with a predominance of brown-brown and bright ocher tones. In the East Europe and North Birds belonging to the Eurasian subspecies live everywhere in Asia.
1.Strix nebulosa lapponica
Strix lapponica Thunberg, 1798, Kondl. Venensk. Acad., nya Handl., 19, p. 184, Lapland, Sweden.
Relatively light color of plumage with a predominance of brown tone. The dark pattern on the underside of the body is less blurred and has more contrast. It is generally accepted that this form distributed throughout the taiga zone, from the western to eastern borders.
There are indications (Dementyev, 1936) that some individuals from the island. Sakhalin, as well as from Anadyr, are identical in plumage color to the American S. n. nebulosa. At one time, S.A. Buturlin (1928) even identified them as a special subspecies - S. n. sakhalinensis. In any case, the striking similarity of these birds to American birds suggests their penetration from continent to continent in our days.
Spreading
Nesting area. This species inhabits the boreal zone of the Northern Hemisphere circumpolarly. In the East Europe and North Asia can be found from Belarus to the upper reaches of Anadyr, the Okhotsk coast and Sakhalin. The northern border is determined by finds on the Kola Peninsula, the Kanin Peninsula (near the Arctic Circle), on the river. Ob (64°), in the bass. R. Taz (65°), on Khatanga (72°), in the basin. R. Yana (69°) and Sredne-Kolymsk. North of the designated line, the great gray owl appears only during non-breeding time, making irregular migrations. In the south it reaches Lithuania (now apparently absent here), Ukrainian Polesie, further to the east the southern border runs along the Smolensk, northern parts of the Moscow, Ryazan and Nizhny Novgorod regions, Tatarstan, Bashkiria, Tyumen, north-east. Altai, Tuva (along the southern slopes of the Sayans), the Amur region (Amur-Zeya plateau and the Amgun river), the Jewish Autonomous Region and Middle Primorye (Bikin river; Pukinsky, 1977). In Primorye the border descends to at least 46°N. In some years, the tawny owl can probably be found further south, up to state border Russia. On Sakhalin, gray owls are distributed up to the middle part of this island (Fig. 17).
Figure 17.
The southern limit of distribution east of the Urals is determined by the following finds. In Bashkortostan, until 1983, no evidence of nesting was known (Ilyichev, Fomin, 1988), later it was proven by finds of nests in the Bashkir west. N. M. Loskutova (1985) and in the northeast of the republic (Shepel, Lapushkin, 1995). To the south, in the Volga-Kama region, the great gray owl is rare and appears only in winter: isolated flights of birds are known for the Penza region, Tatarstan and Mari-El (Kulaeva, 1977). In the Smolensk region. Great gray owl already by the beginning of the 20th century. preserved mainly only in the north, in more forested areas (Grave, 1926). Nesting at the end of the 19th century was established by P.P. Sushkin (1917), later no information was received about the species. For the Tver region. V.I. Zinoviev et al. (1990) provide only two finds of nesting owls of this species for the period from 1965 to 1990. Later observations (Nikolaev, 1995) established that birds are found almost throughout the entire region, most regularly in the areas of large forest-swamp areas of Valdai and adjacent lowlands. The nesting site was identified on the border of the Tver and Moscow regions. within the Zavidovo state complex. Based on summer sightings, nesting of the great gray owl is expected in the Central Forest West. (Avdanin, 1985).
In the Yaroslavl region. the current status of the species is unclear; earlier (Kuznetsov, 1947) this owl was classified as a rare breeding species. In the Moscow region, until 1992, 5 finds of Great Gray Owl were known in the autumn-winter period (Ptushenko, Inozemtsev, 1968); later, in 1992-1993, birds were found during nesting time in the northeast and northwest of the region, and in 1994 nesting was established (Volkov, Konovalova, 1994; Nikolaev, 1995; Volkov, 2000). In general, this owl is extremely rare in the Moscow region. In the Vladimir region. until the mid-1990s. also, only vagrant encounters were known (Kroshkin, 1959; Ptushenko, Inozemtsev, 1968; Volkov, Konovalova, 1994). Now the nesting of the species has been reliably proven for the Petushinsky district, where, apparently, a group lives, which in its distribution also covers neighboring areas of the Moscow region. (Volkov et al., 1998). In the Ryazan region. Nesting was first recorded in 2001 in Oksky West. (Ivanchev, Nazarov, 2003). In the Nizhny Novgorod region. The first discovery of a nest has been known since 1992 (Bakka, 1998). As a nesting species, this owl is here and in the neighboring Ivanovo region. (Gerasimov et al., 2000; Buslaev, in press) is rare, somewhat more common in the autumn-winter period during seasonal migrations.
Outside East Europe and North Asia, in the Old World, the great gray owl is found in the North. Norway, Sweden, Finland (63-64° N) and possibly Poland. In the New World, this owl inhabits the North. America - from the Center. Alaska to Western Quebec. Here the distribution boundary rises northward approximately to the Arctic Circle. In the south it passes somewhere around 50°N. (Stepanyan, 1975) (Fig. 18).
Figure 18.
a - nesting area. Subspecies: 1 - S. n. lapponica, 2 - S. n. nebulosa.
Wintering
As such, they are known only in birds from the American continent, which more or less regularly move south for the winter. Moreover, their wintering zone begins immediately beyond the southern limit of the nesting range and occupies a space from approximately 50 to 30° N latitude. On the territory of the East. Europe and North In Asia, flights outside the main breeding range are exceptional, irregular in timing and, apparently, in essence are close to classic migrations, to which many highly specialized species are prone. However, this issue has been poorly studied in relation to the great gray owl.
Migrations
The degree of sedentism or mobility of the great gray owl requires special study. The need for this is explained by the fact that, along with the nesting of this owl in new locations, there are well-known facts (both in Europe and in Asia) of long-term use by a pair of both a specific nesting site and the same nest. In the Leningrad region, for example, having occupied a far from optimal biotope in a suburban area, one of the couples stayed there for at least five years in a row. Similar data are available for nearby territories - the Arkhangelsk region. (Parovshchikov, Sevastyanov, 1960), the Komi Republic (Sevastyanov, 1968), Finland and Sweden (Merikallio, 1958; Mikkola, 1983), as well as Siberia (Kislenko, Naumov, 1972) and the Far East (our observations).
Let us add to this that there are known cases when, due to a lack of food, in some year, individual territorial pairs did not take part in reproduction, but did not leave their nesting area. All this indicates that at least older individuals of this species are prone to settled life. All in. In America, 18 nesting attempts of 9 pairs of great gray owls were tracked using radio telemetry (Bull and Henjum, 1990). 39% of them nested in the same nests that they used in the previous season, another 39% - no further than 1 km from the previous nest. Only 22% of pairs moved more than 1 km from the old nest. The average distance between old and new nests of the same pair of owls during successive nesting attempts was 1.3 km, with a range from 0.2 to 4.5 km.
At the same time, one cannot ignore the numerous facts of the appearance of birds in places where they were reliably absent before. Sometimes people immediately participate in such colonization big number individuals. This leads to a sharp increase in the local population, especially noticeable in places where the species was previously rare for a long time. This was observed, for example, in the 1970s. almost throughout the entire North-West of Russia (Malchevsky, Pukinsky, 1983). Most likely, this phenomenon is a consequence of the directional dispersion of one-year-old individuals, which initially strive to get to the areas richest in food and concentrate there. In practice, this is expressed in significant movements of birds, as a result of which the young move away hundreds of kilometers from their birthplaces, which has been proven by ringing for birds in Finland (Korpimaki, 1986). The most active development of new spaces occurs in October-November. Shortly before this, in August-September, the natural dispersion of young animals occurs, beginning after the collapse of the broods (Malchevsky, Pukinsky, 1983).
The size of the occupied area can be quite large, up to 3.2 km across. It is also known that in years of abundant food, the size of the site decreases sharply (Pitelka et al., 1955; Lockie, 1955; Blondel, 1967). In the Far East, in the Basin. Bikin, in 1969, during the mass breeding of rodents, 4 pairs of great gray owls lived on larch mari with an area of only 1.5-2.0 km2. The hunting routes of these birds constantly intersected; owls often lay in wait for victims 100-150 m from one another, not paying attention to the actions of their neighbors, and all of them successfully completed breeding. According to data from tracking birds tagged with radio transmitters, males' ranges ranged in size from 1.3 to 6.5 km2, with an average of 4.5 km2 (Bull and Henjum, 1990).
Habitat
In the vast range of the species, the biotopes occupied by individual pairs are quite diverse. However, in all cases, the great gray owl remains a true taiga bird, although in comparison, for example, with the long-tailed owl, it gravitates to lower-density, light-colored stands. In the European part of its range, it prefers to settle in overmature mixed forests (spruce, pine, birch, aspen) near the edges. It often settles in forests of the urem type, enclosing swampy clearings or raised moss bogs. Here the great gray owl settles not only in the zone of the forest edges, but also on large forest islands.
On the Kola Peninsula, Karelia and Arkhangelsk region. (for example, in the Onega region), the favorite biotope is often old pine forests: swampy vakhtosphagnum pine forests with a significant admixture of birch and isolated spruce trees, ripening pine-lingonberry forests, as well as similar in composition, but clearly sparse hill forests, broken by rocky outcrops. Mountain coniferous taiga In general, this species is used both on the Kola Peninsula and in Altai, in the East. Siberia and other areas. In the Komi Republic (Sevastyanov, 1968), this owl most readily occupies birch-spruce-fir forests with an abundance of wood sorrel in the ground cover. In the Krasnoyarsk Territory (Kislenko, Naumov, 1972) and in Yakutia (Vorobiev, 1963), as in most other regions of Siberia, the gray owl prefers to settle in light larch forests. It also inhabits similar biotopes in the extreme southeast of its distribution in the Ussuri region. Here this owl usually nests in light, single-tiered stands of the “northern type”, birch-larch forests growing around larch fields sandwiched by mountains, or on swampy burnt areas. On Sakhalin it inhabits spruce-fir and larch forests (Nechaev, 1991).
Number
In general, the area has enough common bird. However, in most densely populated areas of Europe it is certainly rare. Thus, in the Belarusian forests, the gray owl was more or less common at the end of the century before last (Taczanowski, 1873; Menzbier, 1882) and even at the beginning of this century (Shnitnikova, 1913) was considered “not particularly rare.” But by the beginning of the 1960s. its nesting here is already being questioned (Fedyushin, Dolbik, 1967). IN Belovezhskaya Pushcha it was relatively regularly found at the nesting site only until the 1930s. (Stroutman, 1963).
The distribution of the great gray owl on the European territory of Russia is mosaic in nature and represents a series of areas where the birds are relatively common, while in the rest of the territory they have a low population density, and in large areas they are completely absent. In Nizhne-Svirsky west. (area 35 thousand hectares) in the east of the Leningrad region, according to M.V. Patrikeev (1991, 1998), the number of great gray owls is estimated at 12-15 pairs, locally the nesting density can reach 2.5 pairs per 1000 hectares. In 1990-1991 great gray owl population density in taiga forests Kandalaksha and Umbsky districts did not exceed 2.02 individuals per 1,000 km2 (Volkov, 2000). For Karelia, density estimates are available only for the Kivach and Kostomuksha nature reserves. According to the Red Book of Karelia (1995), in the first of them the density is 1-2 pairs per 100 km2, in the second it was slightly higher: on the same area of 10 km2 in 1988-1993, depending on the abundance of forest lemming, 1-3 pairs of birds nested. In the Komi Republic, the population density of the great gray owl in primary biotopes in years with high rodent numbers reaches 0.3 individuals per 1 km2, more often - 0.05-0.1 individuals per 1 km2 (Mikkola et al., 1997). In different areas of the Perm region. The nesting density of this tawny owl ranges from 0.3 to 0.5 pairs per 1,000 km2, for the region as a whole - 0.3 pairs per 1,000 km2 (Shepel, 1992). The total estimated number is estimated by this author at 40 pairs. For the Nizhny Novgorod region. S. and A. Bacchi (1998) estimate the Great Gray Owl population at approximately 10 pairs. 3-5 pairs can nest in the Moscow region (Volkov et al., 1998). The overall estimated population estimate of the great gray owl in the European territory of Russia is 600-700 pairs (Volkov, 2000), and there is a trend towards an increase in the number of the species. In Finland the population is estimated at approximately 1,000 pairs (Saurola, 1997), representing about 98% of the entire Western European population (Mikkola et al., 1997).
IN Central Siberia and in Yakutia, in biotopes suitable for habitation, this is one of the many owls. In the extreme southeast of the range, in Primorye, it nests sporadically.
Great gray owl numbers fluctuate noticeably throughout the world. They are usually associated with the periodicity of reproduction of rodents - the main victims of this highly specialized myophage. However, global fluctuations are also known for this species. So, from the late 1960s to the late 1970s. there was a steady increase in the population in Finland and Sweden (Mikkola, Sulkava, 1969; Mikkola, 1983). A similar picture occurred in the North-West of Russia (Malchevsky, Pukinsky, 1983). In the latter region until the end of the 1960s. this bird was generally considered one of the rarest, and starting from 1976-79. became more or less normal. Currently, the number of birds in these places has stabilized. The reasons for such fluctuations in numbers are not clear.
Reproduction
Daily activity, behavior
Of all the owls, the great gray owl is the most diurnal. Both in summer and winter, it can be found hunting even during the midday hours. However, daytime activity is most typical for this bird in winter months. Already in February, when the day lengthens, its activity shifts to morning and evening hours. In April-May, when “white nights” begin in northern latitudes, it is rare to see this owl during the day. From this time until autumn it is active primarily during twilight hours.
The time of bird activity is distributed somewhat differently in southern latitudes, for example, at 46° N. in the Ussuri region. Here the day is characterized by comparative constancy, and twilight is fleeting. Under these conditions, gray owls, having begun hunting in the predawn twilight, continue it after sunrise. Then, after a 4-5 hour rest at midday, hunting resumes long before sunset and practically stops in complete darkness.
The developed daily routine of great gray owls extends not only to hunting, but also to mating behavior. The same regime is followed by the chicks in the nest, which daytime usually stay awake while sleeping during the midnight hours. Almost the same can be said about the activity of the incubating bird, which leaves the clutch only at dusk and during the day, spending dark time in the "dream"
Great Gray Owls tend to live in pairs, with the latter possibly being permanent and persisting from year to year. This is also supported by the sex ratio in the population, which is apparently close to 1:1. The increased mortality during the nesting period of smaller males does not contradict stable monogamy, since it is compensated by relatively frequent cases of death of adult females, who lose all caution during the breeding season. However, in recent years in Fennoscandinavia, where the number of great gray owls has now increased sharply, cases of bigamy in this species have been reported, when two females fly into one nest at once, or the nests of the latter are located nearby, and they share a male (Mikkola, 1983).
Despite their large size, narrow specialization and seemingly unconditional food competition, individuals of the species in Eurasia are very tolerant of each other. In the Ussuri taiga, we knew of residential nests located approximately 200 m from one another. In Sweden, a case of two pairs nesting 100 m from each other was described (Hoglund, Lansgren, 1968). Naturally, in such a situation, couples inevitably come into contact, however, no one noted any noticeable conflicts. Moreover, in years with abundant food, in some areas one can observe something like a colonial settlement of these owls. Birds from the American continent have personal hunting grounds from which they expel other individuals of their species (Godfrey, 1967).
Great Gray Owls of the Old World are characterized by increased tolerance in their hunting grounds and towards potential food competitors - other species of owls and birds of prey. Thus, in the immediate vicinity of the nests, within a radius of up to 300 m, the great gray owl, short-eared and long-eared owls, the great owl, etc. can successfully breed offspring. Of the birds of prey, breeding and hunting near the nest of the great gray owl have been recorded by us for the great spotted eagle, buzzard, goshawk, marsh and piebald harriers, hobby hobbies and kestrels. In 1974, in Finland, this owl nested next to a peregrine falcon (Mikkola, 1983); An attack by a peregrine falcon on a great gray owl was noted, after which it began to fly around its nest.
Other birds, including passerines and small raptors, having discovered this owl during the day, although they “call out” to it, do not cause such a commotion as when meeting, for example, with a gray or long-tailed owl.
Nutrition
The great gray owl's diet consists mainly of rodents. In northern Europe these can be voles and lemmings, in Yakutia and the Far East - mainly voles and other rodents. Relatively often, shrews become prey. Less often, this owl manages to catch a chipmunk or a squirrel, and very rarely - birds. The average weight of prey is 25.5 g.
Nutrition comparison three types owls in Belarus (Tishechkin, 1997) showed that the gray owl is the most highly specialized in the choice of food objects. It has the narrowest food niche: if the tawny owl has 51 species of prey in its diet, the great owl has 29, then the great gray owl has only 13. At the same time, the width of the niche for the gray owl (n = 1,517) is 12.96, long-tailed (n = 613) - 5.48, bearded (n = 454) - 4.55. A comparison of diets showed that the long-tailed and great gray owls have a similar range of food items (0.667), while the overlap between the gray and great gray owls is significantly less - 0.448.
The main hunting style of the great gray owl is stalking prey from a perch. At the same time, detection of prey in almost all cases occurs by ear, and not by sight, although the lighting available at the time of hunting would seem to favor the latter. In this regard, the series of photographs of Ero Kamil, presented by Heimo Mikkola in the monograph “The Great Gray Owl” (Mikkola, 1981), is of great educational interest. In these photographs, which capture the hunt sequentially, you can clearly see how the owl, having jumped from its perch and orienting its facial disk to a certain point, smoothly glides over a snow-covered clearing. At the intended place, the bird slows down and, pointing its facial disc downward, apparently clarifies the location of the animal; then, half-folding its wings, it falls to the ground and, breaking through the layer of snow, plunging almost completely into it, grabs the invisible victim. When throwing, the fingers are spread wide apart, and at the last moment both paws are placed in front of the bird's head crashing into the snow. Immediately, having made a deep sweep, scattering snow dust around, the owl takes off with prey or - if the hunt was unsuccessful - without it.
Often, from one perch within a radius of 20-25 m, a great gray owl manages to catch 4-6 animals. If the place is chosen poorly, then, after staying here for 10–20 minutes, the bird moves in a leisurely flight to a new place, where it begins to actively listen, turning its head from side to side. While on a perch, keen on hunting, the Great Gray Owl, even in an open landscape, often allows a person to approach within 20–30 m, i.e. for a sure shot from a shotgun.
When the density of rodents is low, hunting from a perch usually alternates with a search flight. At the same time, the owl slowly flies around hunting grounds(clearings, moss swamps, burnt areas) at a height of 2.5-5 m. In this hunt, hearing is used mainly, although we know of a case when a bird probably visually noticed a shrew running on the crust 100 m away and turned into it side and caught it. More often, the search flight is interrupted by a sudden fall onto the victim from above. Moreover, as in the case of hunting from a perch, the victim does not have to be on the surface. Such a hunt, where hearing is the leading analyzer, is productive only in calm, absolutely windless weather. But under the most favorable circumstances, out of 10 attempts to grab the victim, almost half are unsuccessful.
Like other owls, the gray owl often hunts in the immediate vicinity of the nest, and only the lack of food here forces it to fly further away. Based on observations of males marked with radio transmitters, the birds periodically hunted at a distance of up to 6.5 km from the nest. The daily feed requirement of an adult bird is 150-160 g (Craighead, 1956; Mikkola, 1970b; Mikkola, Sulkava, 1970). According to the same authors, who studied more than 5,000 pellets (their sizes range from 60 to 100 mm in length and from 20 to 40 mm in width), collected from nests and perches in Fennoscandia, the diet of the great gray owl consists of voles 90% ( genera Microtus and Clethrionomys). An insignificant place in their diet is occupied by 6 species of shrews (4.3%), birds (mainly finch fledglings) make up about 1%, frogs - 0.5%, invertebrates - 0.06%. The ratio of different groups of objects may vary depending on the occurrence of preferred victims in nature. Very rarely, especially in lean years, young white hares may become prey for Great Gray Owls (2 cases). In the stomachs of birds caught in Yakutia, in addition to the numerous red-backed voles here, they found pikas (Ochotona hyperborea), forest lemmings, root voles, narrow-skulled voles (Microtus gregalis), water voles and shrews (Vorobiev, 1963). In the Ussuri taiga the most big catch This bird occasionally caught squirrels and chipmunks. Many hunters, and sometimes zoologists, claim that in winter this bird hunts ptarmigan almost everywhere. If this happens, it is extremely rare. Most likely, in this case, the gray owl is confused with some other owl, for example, an eagle owl or a long-tailed owl, or there is carrion feeding, which this owl resorts to in times of hunger.
Gray owls feed their chicks with the same food that they eat themselves.
Enemies, unfavorable factors
The great gray owl apparently does not have specialized enemies in nature. There have been cases of this owl being preyed upon by an eagle owl (Mikkola, 1983). All in. In America, out of 43 individuals marked with radio transmitters (Duncan, 1987), 13 were caught: 5 adults and 8 juveniles. In addition, cases of death of owls from Lynx canadensis(2) and Martes pennanti (3).
The disappearance of this bird from densely populated areas of Europe is the result of many years of direct destruction of adult individuals and their nests by humans. This was facilitated by the unusual innate gullibility of this large bird. It can also be pointed out that in Siberia and the Far East local residents they highly value its meat and hunt it (Vorobiev, 1954). Have negative meaning for species and large-scale clear-cutting.
Economic importance, protection
If we see benefits in owls feeding on rodents, then of all our owls the great gray owl is the most “healthy”. For six summer months According to observations in Finland (Mikkola, 1970), one pair destroys about 700 small rodents. However, the great gray owl, like other owls, cannot be called “beneficial” or “harmful.” These birds are playing important role in natural ecosystems. The Great Gray Owl is also important in aesthetic terms - it is one of the most beautiful, large and, at the same time, trusting owls of the northern taiga.
To preserve the species, it is necessary to promote its protection and strictly adhere to the ban on shooting. A positive result can be achieved by constructing artificial nests from branches in the forest edge area, near swamps and clearings. The great gray owl occupies such platforms quite willingly.
The Great Gray Owl is listed in the Red Books of Ukraine, Belarus, Estonia, and in Russia - in the Red Books of Moscow, Nizhny Novgorod, Tver, Arkhangelsk, Leningrad, Murmansk, Kirov, Perm, Sverdlovsk, Kurgan, Novosibirsk, Tomsk, Magadan, Sakhalin regions, Karelia , Komi Republic, Mari-El, Tatarstan, Udmurtia, Altai Republic, Buryatia, Koryak and Chukotka autonomous okrugs. A proposal has been made on the advisability of introducing the Great Gray Owl population European Russia to the Red Book of the Russian Federation (Volkov, 1998).
Appearance and behavior. A large owl is approximately the size of a chicken (body length 59–70 cm, wingspan 130–158 cm, weight 600–1,900 g), on average 15% larger, twice as large, approximately half as light, although comparable to him in overall length (the eagle owl is stockier and looks more “barrel-shaped”). The impression of a very large bird is enhanced by its loose plumage. The wings are very long, wide and blunt, the tail is quite long (protrudes noticeably beyond the ends of the folded wings), rounded. What stands out is a very large head, even for an owl, with a very well-defined facial disc; in profile, the “face” is almost completely flat, as if cut off, which is clearly visible in flight (in the eagle owl it is rounded). The flight is silent, light, the flapping of the wings is slow, measured (“stately” flight in the manner of a gray heron), often gliding on outstretched wings. Leads predominantly crepuscular and night look life, but is also active during the day.
Description. The general color tone is gray-brown or dark gray, grayer and darker than that of the great owl. The upper body is almost gray, there are numerous longitudinal brown streaks on the back, there are also light spots that line up in two light lines on the shoulder and wing. The top of the head is finely streaked longitudinally and transversely with dark lines. The chest and belly are somewhat lighter, with large longitudinal brown streaks. At close range, small transverse “branches” of these streaks are sometimes visible, especially on the chest (not present in the Great Gray Owl). The flight feathers are cross-striped, brown spots at the base of the primary flight feathers on the open wing above form a light brown field that contrasts with the rest of the darker surface of the wing, and this is sometimes noticeable in a flying bird (the great owl does not have such a feature). The tail is cross-striped with relatively thin dark stripes; in addition, unlike our other owls, the ends of the tail feathers are darkened and form a wide dark stripe at the end of the tail, which is noticeable both in a sitting and in a flying bird. The pattern of the facial disk of this owl is very characteristic: thin dark concentric circles are visible on a gray background, there is a black “beard” around the beak and under it, along the edges it has white spots and two white half-rings around the eyes above the beak. The eyes are yellow (unlike our other tawny owls), the beak is light. The expression on the “face” is not “kind” or “wise,” but rather “stupid-angry” or “wary-surprised.” The legs and fingers are feathered down to the claws.
The male and female do not differ in color; the female is noticeably larger. The chick hatches in white-gray thick down, which at the age of a week begins to give way to mesoptile. The mesoptile is dark brown (darker than the color of adults and the color of fledglings of other tawny owls), the underparts are covered with transverse dark thin stripes, the upper part is covered with transverse dark and light stripes and mottled spots. The facial disc is darker, forms a “mask” (not found in fledglings of other tawny owls), it becomes lighter with age, and concentric stripes begin to appear on it. The first adult plumage is mostly formed at 4–7 weeks of age, but remnants of the mesoptile on the head and elsewhere are visible until 2–3 months of age. In the first adult plumage, the young bird can hardly be distinguished from the adult: it is slightly darker, the flight feathers are worn equally in autumn and winter (in adults they are of different ages).
Voice. The male's current calls are a measured series of dull hooting calls of 8–12 syllables " oo-oo-oo-oo-oo-oo-oo-oo-oo" The series lasts about 6–7 seconds, the interval between sounds is about 0.5 seconds, towards the end of the series the sounds become lower, come out faster and quieter, as if they fade away. It resembles the mating of a long-eared owl, but all sounds are much lower and pronounced much faster, but not as fast as those of a short-eared owl. The song is usually heard no further than 400–800 m. Occasionally, females also scream similarly, but more rudely. There are other sounds, quite varied. The fledglings emit hoarse cries " psiip"or sharp" yik-yik-yik».
Distribution, status. Taiga zone of the Northern Hemisphere. In European Russia it is distributed from the mixed forest zone (from approximately 55° northern latitude) to the northern taiga. Overall quite normal look, but on southern border range and in densely populated areas is rare. The number fluctuates depending on the number of mouse-like rodents. In recent decades, numbers have increased in many areas, and their range has expanded to the south.
Lifestyle. Inhabits taiga-type forests, preferring sparse light-colored stands adjacent to swamps, burnt areas, and clearings. It nests mainly in old nests of birds of prey, which are located near the trunk in a sparse crown so as to provide good visibility and free approach. Occasionally nests in recesses at the ends of tall stumps. There are known cases of nesting on the roofs of abandoned buildings and on the ground. Doesn't build nests or make lining. There is evidence that the nests are always clean, since the female eats the pellets and droppings. The clutch consists of 3–5 (up to 9) white eggs. The female incubates the clutch, the chicks are fed by both partners. The chicks are of different ages, since incubation begins with the first egg. Near the nest they behave aggressively, especially the female, they can attack people and hit them with their claws.
The tawny owl closely watches the person.
Science and life // Illustrations
The chicks, hiding, never moved.
Take off!
Owls, tireless hunters, adorn our forests. It is a rare pleasure to watch the flight of these graceful predators, especially in winter, when there is a fantastic gray shadow glides against the backdrop of a snowy forest.
One of the largest owls is called bearded owl for a reason; you just have to look at its facial disc, decorated with an almost black “beard” under a powerful beak.
It is second in size only to the eagle owl and polar owl: wingspan is about one and a half meters. Body weight is also quite decent: in females, larger than males, it usually exceeds one kilogram. The long claws at the ends of the tawny owl's eight toes are sharpened, like a good awl. The outer fingers, like those of all owls, bend down to make it easier to grab prey. Once I had the opportunity to experience the power of its claws on my own skin, getting to know the tawny owl better.
It was near my home village, in the south of the Tyumen region, where birch forests interspersed with fields are very convenient for nesting birds of prey. One spring, returning from duck hunting, I noticed with my peripheral vision an unusual dark spot against the background of a bare aspen tree, and through binoculars I saw a great gray owl sitting on an old buzzard’s nest. As I approached, the bird flew away.
At the beginning of summer, armed with a camera, my partner and I came to the treasured aspen forest in the hope of photographing both the owl and the chicks. The owner was at home, looking menacingly out of the nest. Seeing us, she flew out and sat down nearby with a silent reproach. In order not to disturb the chicks too much, I chose a nearby tree as a shooting point and began to climb, remembering my childhood skills. The tawny owl sat modestly aside, and I let it out of sight for a while. But at a height of about seven meters, when it would have been unpleasant to fall, I almost let go of the branches from my hands from an unexpected strong blow to the side - this one-kilogram aircraft rammed me full speed with all his eight claws so lightning fast that I didn’t even have time to see him. A minute later - a new approach to the target and another blow to the same point, and again unexpectedly. With such respectable dimensions, the noiselessness of an owl’s flight is striking. When large bird absolutely silently flies nearby and at the same time only a light breeze is felt from the flapping of its wings, creating the feeling of a silent movie. This is how the plumage of owls is arranged: the edges of the flight feathers are cut into small teeth at the front and fluffed at the back. And all the plumage is soft, loose, to dampen the sound of air currents.
Now I no longer let the defender of the nest out of sight, and rightly so: another blow was looming in the face, and only at the last moment I managed to put my elbow in, which took the blow. Clearly satisfied with the effect produced, the tawny owl sat down behind me, loudly clicking its beak, and its whole appearance said: well, do you want more?
It is unlikely that the owl understood my explanation that I only intended to photograph the owlets and would not eat them, but after listening to my confused speech and deciding that I had had enough, she switched to my partner, who was standing below. The bird sat down in front of him and began clicking its beak. And I, taking advantage of the moment, safely descended to the ground and, having said goodbye to the brave defender, went to “lick my wounds.” They write that the gray owl even attacks a bear at the nest.
While the female incubates the clutch (the process takes 28 days), the male hunts to feed his girlfriend. Males are usually not as aggressive. If the male is not far from the nest, when a person approaches, he tries to remain unnoticed, clinging to the tree trunk and standing at attention. But if his wife screams for help, he will immediately rush into battle.
Tawny owls feed mainly on rodents. According to the observations of Finnish ornithologists, one bird eats about seven hundred mice and voles in six months.
After about a month, when the owlets leave the nest and begin to fly, the parents let their guard down. The owls look awkward Stuffed Toys and look down on their surroundings with curiosity.
Later I met owls many times in different time and found nests. And I realized that photographing them is not so difficult if you know their habits. Adult owls also often show curiosity in the fall, and if, having discovered an owl, you approach it slowly and not directly, but tangentially, as if walking past or picking mushrooms, the bird may let you in close quarters, giving the opportunity to photograph her. And if you stand longer, without making sudden movements and trying not to look in its direction, the owl itself may even fly closer to take a closer look at the photographer, funnyly rotating its head. And then the reward for patience will be not only the indescribable (sometimes even too acute!) impressions of meeting with the most beautiful bird, but also interesting shots that can be taken even with an ordinary inexpensive camera.