Short-eared Owl

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Short-eared Owl
Short-eared Owl (Asio flammeus)

Short-eared Owl ( Asio flammeus )

Systematics
Class : Birds (aves)
Order : Owls (Strigiformes)
Family : Real owls (Strigidae)
Genre : Ear Owls ( Asio )
Type : Short-eared Owl
Scientific name
Asio flammeus
( Pontoppidan , 1763)

The Short-eared ( Asio flammeus ) is a bird art from the genus of the ear owl ( Asio ) within the family of authentics owl (Strigidae). Their short feather ears are usually laid out and therefore not visible. The English name Short Eared Owl emphasizes this trait, while the German emphasizes the species' habitat preferences for wetlands and marshland .

With a body length of around 40 centimeters, the bird, which is almost the size of a crow, occurs almost worldwide in at least seven subspecies, making it one of the owl species with the largest range. Short-eared owls are one of the few species of the Strigidae that have managed to colonize islands far from the coast. It is the only species of owl in Hawaii.

The partly diurnal, mostly ground-brooding owl feeds mainly on small mammals, especially voles . In many areas, their populations have declined sharply in recent decades. In Central Europe it is a rare breeding bird with widely scattered breeding occurrences. Short-eared owls lead a largely vagabond, not very localized life, the more northern populations are migratory birds with migration distances of several thousand kilometers.

features

Appearance

Rather gray-brown colored owl of the nominate form from South West England
Short-eared Owl in flight

The plumage of the short-eared owl is quite variable. Typical are straw or pale reed-brown basic colors, there are also specimens in warm brown tones and gray individuals with a very light, almost white underside and leg fletching. Characteristic of the species are the black rimmed eyes with the sulfur yellow iris, the round head usually without visible feather ears and the clear longitudinal lines on the ventral side.

A typically colored short-eared owl of the nominate form is irregularly and coarsely reddish-brown flocked on the upper side on a reed-yellow or straw-colored background. In this pattern there are teardrop-shaped white markings that can be clearly visible on the back and shoulder. The arm covers are darker and often not drawn. The wings of the hand are colored similar to the upper side and are clearly banded, mostly triple dark brown. This banding continues on the arm wings , which are significantly lighter at the bases and often have a light reddish-brown, sometimes orange-brown hue; this feature and the dark arm covers are also noticeable in the seated bird. The tail, which has just been cut off and has multiple dark brown bands, is reddish brown. The swingarms and the control springs have a conspicuously white border on the top, the outer flags of the outer control springs are white. The neck and head are dashed reddish brown and irregular dark brown. The short, closely spaced feather ears are usually not perceptible at all or only as small stubs. Fully erect when excited, they protrude less than an inch from the head plumage. The underside is overall lighter yellowish cream in color, darkest in the throat region and becomes lighter towards the rump. It is clearly dark brown with vertical dotted lines, transverse drawings like the long-eared owl are missing. The legs and toes are densely feathered in the basic tone of the underside. The claws are dark horn-colored. The wings and tail are very light on the underside and particularly conspicuously banded across at the tips of the hand wings. A dark, crescent-shaped wrist point is striking . The face veil is broadly heart-shaped, with a dark-light border and drawn with dark rays on a light ground that is slightly darker towards the edge. The lower border is often pure white, especially in older birds. The eyes are surrounded by a striking and typical black mask, the iris is yellow. A bristle-like, light feather border partially surrounds the eyes and the beak and forms a striking X-mark.

The sexes do not differ in color; the first adult dress largely resembles the annual dress of this type.

Characteristic for the flight pattern of the species are the long, slender wings with the bright underside, often almost without drawing except for the tips. Short-eared owls fly with powerful, deeply drawn wing beats , glide like a whip in a slight V-position and often shake .

Biometric data

Short-eared owls largely correspond in size to the long- eared owl , but are more compact and much heavier than them. The reverse gender dimorphism is moderate in terms of weight, but normal in terms of height. The females are heavier and weigh an average of 420 grams, the males 350 grams. Weights below 280 grams are considered hunger weights for the nominate form . The body length of adult owls ranges from 34 to 42 centimeters, the wingspan is between 97 and 107 centimeters, the highest values ​​again being attributable to females.

Weight and size vary considerably between the various subspecies: individuals of the nominate form and the subspecies A. f, native to southern South America . suinda are the largest and heaviest, those of the island shape A. f. ponapensis of the Carolines the smallest and lightest.

Acoustic expressions

Short-eared owls have a range of sounds, calls, and instrumental sounds . The male's call to territory is a hollow, not very loud "Hu" or "Bu" that is strung up to 20 times. The call sequence, which rises slightly in pitch, is somewhat reminiscent of the hoopoe calls . The call is made both while flying and seated. The calls of the females have a hissing, hissing character and are difficult to transcribe. In conflict situations and when worried, a meowing, drawn out "Kiiijá" can be heard, in which the second syllable is clearly emphasized.

The clapping of wings of this species of owl is impressive, which is used both during courtship in swoops as well as in arguments with rivals. The flapping of the wings in rapid succession creates a crackling sound reminiscent of the flapping of a flag. Like other owls, short- eared owls hiss or snap their beak in conflict or defensive situations .

Mauser

From the fifth day of life growing Mesoptil to neutral Eidunen one. The growth of the large plumage begins around the 10th day of life. In the juvenile moult , which already sets in after 25–28 days, the mesoptile plumage and large parts of the arm covers are largely replaced. This moult is completed after about 30 days. The immature, around 2 months old owl is difficult to distinguish in its first adult dress from owls in old age. Sometimes mesoptile residues remain in the abdominal area for a longer time and also enable age determination by field ornithology. The annual moult of adult birds begins with the large plumage of the females, often during breeding. Starting with the first hand swing arm, the swing arms and the control springs are completely changed. The change of the small plumage begins a little later and ends in late summer or early autumn.

Similar species

If the observation conditions are sufficient, the short-eared owl can always be identified, but confusion could occur with flying birds. It is not possible to determine gender in a field ornithological manner without a situational reference.

The long-eared owl and the screeching owl ( Asio clamator ) can be used for confusion . Both owls have distinctive, always visible feather ears. The long-eared owl is slimmer, the face veil is narrower, the eyes are dark orange. The underside is not only dashed lengthways, but also slightly drawn across. Their wings are shorter and rounder and on the underside darker and usually more clearly banded. The tail has more numerous and narrower bands than that of the short-eared owl.

The screeching owl differs apart from the typical vocalizations by the wide, black rimmed face veil and the somewhat smaller size.

Distribution area

Distribution area of ​​the short-eared owl. Directions of pull were marked by blue arrows. Green arrows indicate island occurrences. Outside of the breeding season, the species can occur in large areas south of the known breeding areas.

The range of the short-eared owl is very large, among the owls it is only surpassed by that of the barn owl . In most areas the species is not represented across the board, but only occurs scattered, following the respective food supply, so that the breeding density of this species is subject to very large fluctuations. In a large-scale Finnish study between 1986 and 2004, between one and 132 nests were flown; In 2005 this number increased to 304 nests, only to drop back to 55 nests the following year.

In the Nearctic , the species colonizes North America south to about 35 degrees of latitude. The northernmost breeding areas are on Banks Island and Victoria Island . Short-eared owls breed on some of the Hawaiian islands, 4,000 kilometers from the mainland . Another occurrence in the Pacific is known from Pohnpei , an island of the Caroline Islands , and some Mariana Islands . In the Caribbean , the short-eared owl is a breeding bird of all the Greater Antilles Islands and some of the Lesser Antilles . In South America, the densest occurrences are in the southern half of the continent and extend there to Tierra del Fuego ; it breeds scattered and rarely in the northern part and in the Andean regions. The short-eared owl is also a breeding bird in the Falkland Islands and the Juan Fernández Islands . The long eared owls of the Galapagos Islands , which were long considered a subspecies , were separated as a separate species, the Galápagos eared owl ( Asio galapagoensis ).

In the Palearctic , the most westerly breeding populations are on Iceland , where it is the only species of owl, besides the occasional snowy owl. It occurs very scattered in Great Britain , it is found frequently in Ireland , broods have not yet been confirmed. Short-eared owls breed in western, south-western and central Europe very scattered and fluctuating in density. It is not certain whether there are breeding occurrences in the southern Balkans and in Turkey . The largely closed Palearctic distribution area includes large parts of Scandinavia , the Baltic States , Belarus and the Ukraine and extends eastward in a wide belt to the Pacific coast . The northern limit of the Palearctic distribution is 70 ° North, the inconsistent southern limit fluctuates around the 50th parallel. The southernmost occurrences are in the Central Asian steppes between the Caspian Sea and the Aral Sea .

In Germany, apart from the breeding areas in northern Germany and on some of the Frisian islands , in particular on Borkum , there are some known breeding sites south to the northern edge of the Alps, but only temporarily occupied. In southern Germany, the species brooded most frequently in the Swabian Donaumoos near Ulm , most recently in 1979. In Bavaria it is considered a very rare, irregular breeding guest. After 19 years without proof of breeding, three successfully breeding pairs were found in the Nördlinger Ries in the strong mouse year 2005 .

In Austria, in good vole years, the short-eared owl breeds in the Seewinkel of Lake Neusiedl with up to 20 breeding pairs, but does not breed there regularly either. The deposits in the Rhine delta in Vorarlberg are extinct. Neither historical nor current breeding records are available from Switzerland.

hikes

Migration route of an adult, probably female short-eared owl. She was telemetered near Nome in late June 2009 and was in northern Mexico in early November 2009. The straight-line distance is more than 6,000 kilometers, the flight kilometers covered up to this point more than 26,000.

The short-eared owl is similar to hawk a very vagile little localized owl. Only the island populations are naturally largely localized. Young birds, in particular, roam very far after becoming independent. A 1961 Borkum nest young ringed owl was killed in November of the same year in Portugal; after flying out she had covered a distance of over 2000 kilometers. All breeding birds from the northern breeding areas migrate to southern areas in winter, Scandinavian and Central European breeding birds also in western directions to the Atlantic coast or England. Hikes over several thousand kilometers are not uncommon. Owls that breed south of the 50th parallel often seem to be resident birds or only lead a small-scale nomadic life. Winter roosts for Palearctic birds are in the Mediterranean, some migrate as far as the Sahel region south of the Sahara. Eastern European and Asian short-eared owls often overwinter in the Black Sea region and the steppe areas of Central Asia. In winter they can reach southern India , southern China , Taiwan and Japan . The High Nordic Nearctic populations migrate south in winter. During this time of year the species can be found in suitable habitats throughout the southern USA and northern Mexico . Some populations from southern Patagonia are migrating north. The species has been found in Greenland , Madeira and the Azores . Occasionally short-eared owls land on ships far from the nearest coast.

Short-eared owls leave the breeding area very soon after the young birds have fled. However, the actual purposeful move doesn't start until September and peak in October. The species roams widely in winter quarters. In areas with a particularly abundant food supply, large societies of up to 200 individuals in exceptional cases can temporarily reside and then, like the long-eared owl, form larger sleeping communities.

In Central Europe there are inflows with subsequent breeding far away from regular breeding sites if two conditions are met at the same time. There must be weak rodent populations in the normal breeding areas in the north and east of Europe with a simultaneous mass occurrence of field vole and / or earth mice in inland Central Europe.

habitat

Breeding habitat of the short-eared owl in Seewinkel (Neusiedlersee - Austria)

Short-eared owls need open, largely treeless landscapes with partially low vegetation, which are interspersed in a mosaic-like manner with shrub, sedge , or reed bed sections and thus offer the species cover and the necessary breeding grounds. It is not necessarily dependent on wet habitats, but it finds suitable habitat structures especially in such areas, especially in Central Europe. In terms of their habitat requirements, it is very similar to different types of harrier , especially the corn and meadow harrier .

Short-eared owls breed mainly in the tundra , in sparse tree-lined heaths and moors , in silted areas, dune areas and salt marshes near the coast . It can occur in extensively used agricultural land, such as on wet pastures, especially hat pastures , on agricultural fallow land, in very sparse forests and afforestation as well as on large clearcuts in the middle of contiguous forest areas. Broods have been observed in grain fields, in Cuba in sugar cane plantations. In the Nearctic it breeds in the tundra region, in the south especially in the grass steppes of the Great Plains and in the Neotropic in the Pampas of Patagonia . In the Andean region, it rises up to the Páramo mountain steppes , where it reaches its highest breeding grounds at an altitude of around 4,000 meters. The few inland breeding areas are almost without exception in wetlands, often in peat bog areas overgrown with sedges .

Settlement density

In good vole years, short-eared owls can breed in close proximity to each other, but claim separate territories. In 1967 16 pairs brooded in the Donaumoos; the area sizes were between 9 and 22 hectares. In Alaska, territories with average sizes of 20 hectares were found, in Scotland 45 hectares. In general, the size of the area depends on the general availability of food and the quality of the hunting area. The hunting areas are often outside the hunting grounds, sometimes up to two kilometers away from them.

In the Western Palearctic, the field mouse is by far the most important prey animal

Food and subsistence

food

Short-eared owls feed themselves and their nestlings mainly on small mammals, especially voles . Among these, the field mouse ( Microtus arvalis ) is by far the most important prey animal in the Western Palearctic . Other species of vole, such as the earth vole ( Microtus agrestis ) and various species of lemmings , are also frequently hunted. In the Eastern Palearctic and in North America, Microtus species also dominate the food spectrum, in the Nearctic the meadow vole ( Microtus pennsylvanicus ) alongside lemmings. The deer vole ( Peromyscus maniculatus ), which also lives on the surface in winter and is not subnival like the vole species, can become an important part of the diet, especially when there is high snowfall . An extensive study from Massachusetts quantified food composition during and outside of the breeding season. During the breeding season, 83.5% mammals, 12% birds and 4.5% insects were found, outside the breeding season 95% mammals and 5% birds. The meadow vole has always been the most important prey animal. In places where voles do not occur, for example in Iceland, other small rodents form the basis of food, in Iceland this is the wood mouse ( Apodemus sylvaticus ). In addition to these main prey animals, the short-eared owl beats a large number of different small mammals, such as representatives of the real mice , such as the yellow-necked mouse ( Apodemus flavicollis ) or the brown rat ( Rattus norvegicus ), pocket rats , shrews and others up to the size of young hares. When the main prey animals, especially voles, become scarce, short-eared owls migrate. In the meantime, birds can form an important substitute food. In coastal areas they are regionally part of the main food. In addition to various small birds, limicoles , terns and small species of seagulls play the most important roles among the bird prey . Remnants of insects, amphibians and reptiles were found sporadically in the ridges. Food analyzes of South American populations were for South chile Abothrix olivaceus and the Norway rat as its main prey. Rodents of the Loxodontomys genus can also become important prey there, especially in agricultural regions. Short-eared owls of an Andean population in northwest Argentina made up over 80% of Calomys lepidus and Eligmodontia puerulus . Short-eared owls frequently hunt birds in the Hawaiian Islands. On Kaua'i , the species is the most important predator of the threatened Palmer thrush ( Myadestes palmeri ).

The daily food requirement of adult birds is 70-80 grams of prey weight, which corresponds to about two to three voles. In relation to this, young birds need larger amounts of food, especially at low ambient temperatures these are comparatively very large with up to seven lemmings per day.

Vaults

The vaults are usually found at the foot of the waiting room and under the day rest areas. They are dark gray, firm and compact. In larger series, average dimensions of 48 × 22 millimeters were found.

Hunting strategies

Short-eared Owl in flight

The most common hunting method used by the short-eared owl is flight search. It flies over its hunting area at a height of 0.5–3 meters, mostly against the wind, and returns to the starting point at the territorial boundaries in order to start a new search flight, slightly offset. The flight is slow, weihenartig- gaukelnd , restless and varied varying by glides, Rüttelphasen and height adjustments. The prey animals are localized both visually and acoustically. If a prey is located, the owl usually shakes briefly before dropping with pointed toes. Short-eared owls hunt less often from greater heights, often shaking them persistently. This hunting method seems to be used mainly when there are fewer small mammals. Especially in bad weather and when the snow cover is closed, the species also hunts from sitting. Prey animals that have escaped or were only injured in the first attack pursue short-eared owls running or with flutter jumps. They can locate their prey under a closed blanket of snow of up to 10 centimeters high and in the thick felt of the ground vegetation and beat it successfully. The prey is often already killed by the impact, otherwise by a neck or head bite, swallowed on the spot or transported in the claws (less often in the beak) to a feeding place or to the nest. The short-eared owl usually bites off the head and wings of birds, while in larger birds it often only eats the breast meat. When there is an excess of food, the short-eared owl deposits prey in the nest area. Sometimes the short-eared owl also hunts other birds such as hen harriers or kestrels for food.

The success of the hunt depends on the amount of prey and the local and climatic conditions. A North American study evaluated 628 hunting attempts of the short-eared owl and only 137 of these were definitely successful. A comparative study of the hunting behavior of the Hudson's harrier and the short-eared owl in a disused opencast mining area in Kentucky found a slightly higher success rate of the short-eared owl with almost identical hunting methods and the same prey species. However, in this study, too, successful attacks were at a rather low level at 11 and 7 percent, respectively.

behavior

Activity and comfort behavior

The activity pattern of the species corresponds roughly to that of the hawk owl . Its activity peaks are in the twilight hours, but it is also active during the day, especially during the courtship and breeding season. Short-eared owls spend most of the time lunchtime and the hours around midnight resting or engaged in comfort activities. In areas where short-eared owls are exposed to strong bullying pressure from seagulls and skuas , they reduce their daily activity very much or stop it altogether.

The short-eared owl spends its resting times dozing either in good cover on the ground or on a branch, usually pressed close to the trunk. On the ground, she can sit bent over on her heels or lie stretched out flat; on a branch she takes an upright position. In this camouflaging rest position, the face is narrow, the feather ears are erect. During the time of territorial demarcation and during the breeding season, she can often be seen in exposed waiting areas during the day.

Short- eared owl hates a buzzard

Short-eared owls spend a lot of time caring for their plumage. They bathe extensively in the sun, turning their face and chest towards the sun and letting their wings hang down. In this position they also expose themselves to the rain. Bathing in the sand or water baths have not yet been observed.

Social, territorial and enemy behavior

Short-eared owls live in pairs during the breeding season, but their social behavior is characterized by a mutual need for distance. They rest in separate units, social interactions have not been observed. Outside the breeding season, larger groups can come together in rich feeding areas and rest in close proximity to each other and hunt together, but not cooperatively. Sometimes these groups are associated with long-eared owls and Hudson harriers .

During the breeding season, the short-eared owl is strictly territorial. The area is marked acoustically by shouts and clapping of wings, optically by area flights and conspicuous sitting in exposed waiting areas. Intruders, both conspecifics and other owls, birds of prey or crows, fly towards short-eared owls and try to drive them away by flight maneuvers. Sometimes there are real fights against contact. Rival fights can be impressive, the main element of which is the soaring of the opponent with protruding claws. Sometimes they fall to the ground, clinging to each other, and chase each other there with screeching, meowing calls. If predatory mammals, grazing animals or humans come too close to the nest, short-eared owls either attack directly or try to divert them, like many ground-brooders, by enticing them and thus keeping them away from the nest. Birds of prey, especially harriers, seagulls and skuas attacks the species particularly emphatically.

Outside the breeding season, short-eared owls continue to hate birds of prey, crows, gulls and skuas intensely, but when enemies and humans approach, they usually rely on their camouflage and crouch in the thick vegetation.

Breeding biology

Courtship, pairing and nest

Short-eared Owl in Nederlandsche Vogelen 1770

Short-eared owls become sexually mature in the autumn of their first year of life. Most seem to breed for the first time in the following spring. As far as is known, they have a monogamous seasonal marriage.

The courtship can already begin in the winter quarters, but reaches its climax with the territorial delimitation in the breeding territory. The main element of courtship and territorial delimitation are the male's impressive flights, accompanied by frequent calls. It rises to considerable heights with remarkably slow, exaggeratedly sweeping wing beats, presenting the bright undersides of the wings. At the climax of this trajectory, which always remains above the territory, it tilts steeply downwards and claps its wings in rapid succession during this dive. More sexually motivated courtship elements are the slow demonstration flight in an extreme V-position and the rocking flight, in which the owl alternately tilts back and forth due to the asymmetrical flapping of its wings. The male pauses over an intended nesting site and spins to the ground. When the female also settles down with her wings clapping and calling for territory, the pairing is usually complete. Loot transfers lead to the first copulations, which always take place on the ground.

Short-eared owls are one of the few species of owl that regularly build nests, but the extent of the nest-building activities varies greatly from person to person. The nests can be simple, only lightly scraped or lowered hollows, but can also be compact constructions made from different materials from the surrounding area and designed with nesting material. Laying eggs on completely unadapted ground does occur, but is rare. The nest is always on the ground in dense vegetation, if possible on dry, sometimes slightly elevated ground. There are often control rooms in the immediate vicinity, from which the male can monitor the environment. Since short-eared owls always land in some area of ​​the nest, tunnel-like walkways often lead to the nest.

Clutch and brood

Egg, Museum Wiesbaden collection

In Europe and North America, oviposition begins in mid-March and peaks in April. Fresh clutches can be found until June and July. Short-eared owls start breeding in June at the earliest in northern regions. In exceptional cases, probably with an exceptionally good supply situation, there may be autumn or winter broods. From South America only a few data are available that suggest the South American spring and early summer as the main breeding season. Breeding short-eared owls were found in the Colombian Andean regions in September and in Patagonia in November.

Short-eared owls breed once a year, and twice in particularly good mouse years. Replacement clutches are likely to occur, but have not yet been proven with certainty, as the species usually leaves the breeding area after the clutch has been lost. In bad mouse years, the owls do not brood at all, or the clutches are very small.

A full clutch consists of 7–10, (4–14) matt-glossy, round to oblong oval, initially pure white eggs with an average size of 40.4 × 31.3 millimeters and a fresh weight of around 22 grams. They are laid every two days and only incubated by the female from the first egg. It seldom leaves the nest during the breeding season and in the early rearing phase and is supplied with food by the male. After an incubation period of 26–29 days, the chicks hatch according to the laying distance, so that chicks and nestlings in extremely different stages of development gather in a short-eared owl brood. Killing of the younger boys by both siblings and the female does not seem to be uncommon. It is uncertain whether depositing surplus prey in the nest environment will counteract this tendency to fratricide . In extreme cases, the oldest nestling leaves the nest when the last chick hatches. After about 12-18 days, the young owls that are not yet able to fly, but able to walk well, spread out in the dense vegetation around the nest. You will be looked after by both parents for some time after you have reached full flight ability for around 35 days. It is not known what role the parents play in the further development of the juvenile owls, a loose family connection was observed until they moved away in autumn.

Breeding success and life expectancy

The escape rate depends on the availability of food, the weather conditions and the predation pressure from various soil enemies such as foxes , wolves and martens as well as birds of prey, crows, gulls and skuas. 44 young hatched from 121 eggs in the Donaumoos, 33 of which left the nest. In Manitoba , 174 young owls flew out of 235 eggs. In contrast, in a study in Alaska, at least one young owl flown out was found in only 50% of the nests.

The previous maximum age of a short-eared owl in the wild was determined to be 20 years and 9 months. It was an owl ringed while nestling on Spiekeroog , which was found dead there again. However, the average life expectancy is much lower for this species. As a ground breeder and migratory bird, it is exposed to a variety of dangers.

Systematics

The short-eared owl is a member of the genus of eared owls ( Asio ), to which 8 species belong. It is very closely related to the African Cape eared owl ( Asio capensis ). Seven subspecies are recognized by König and Weick :

  • Asio flammeus flammeus ( Pontoppidan , 1763) : The nominate form is common in Europe, Asia and North America.
  • A. f. bogotensis Chapman , 1915 : This subspecies occurs in northern South America, on Trinidad and Tobago and in the Andes to northern Peru. The owls of this subspecies are smaller and darker than the nominate form.
  • A. f. suinda ( Vieillot , 1817) : Inhabits central and southern South America to Tierra del Fuego. It is largely similar in size and color to the nominate form. On the chest it has a reddish brown, Y-shaped drawing.
  • A. f. sanfordi ( Bangs , 1919) : Island race of the Falkland Islands. Slightly smaller and lighter than ssp. suinda .
  • A. f. sandwichensis ( Bloxam , 1817) : This small, yellowish-gray subspecies is found on some of the Hawaiian Islands.
  • A. f. ponapensis Mayr , 1933 : Rather small, mainly short-winged island breed from the Caroline Islands , especially Pohnpei .
  • A. f. domingensis ( Statius Müller , 1776) : This subspecies occurs on the Great and some of the Lesser Antilles .

The Handbook of the Birds of the World also states:

The Galápagos eared owl Asio galapagoensis ( Gould , 1837) is currently considered by the majority as an independent species.

Stock, stock development and causes of risk

The population of this nomadic and vagabond species is difficult to assess. According to the IUCN , the worldwide population of the species is not endangered, but detailed population information is missing for large areas. In Europe, after the massive slump in the second half of the 20th century, the population is largely stable, only in Great Britain, the Netherlands, Sweden and Belarus is it falling further. An extensive population-dynamic survey of ground-breeding birds in steppe areas of the Transwolga region resulted in stable findings for the short-eared owl. In North America, the short-eared owl population is declining in most regions; in some states, especially in the eastern United States, the species has become extinct in recent decades.

The total European population is estimated to be at least 58,000 breeding pairs. After the European part of Russia, the largest stocks of this species are in the Scandinavian countries.

In addition to many natural hazards, short-eared owls suffer particularly from the amelioration of wetlands. The sharp decline in stocks in Europe and North America in the second half of the 20th century can mainly be attributed to such measures. When short-eared owls move into agricultural areas such as hay meadows or grain fields, a large number of broods are destroyed during mowing or harvesting. If possible, in consultation with the local farmer, conservationists set up a protection zone with a radius of around 40 m or an area of ​​70 X 70 m around the breeding site, which is only mowed after the young owls fly out. The farmers receive compensation payments for this.

The species suffers major losses on its migrations and migrations through direct shooting as well as accidents on power lines, wind turbines or pasture fences.

In Germany the short-eared owl is considered to be critically endangered (Red List Cat. 1).

The species belongs to Appendix I of the EU Birds Directive (RL 79/409 / EEC).

literature

Individual evidence

The individual references refer to the cited literature. Some of the technical papers used are available as pdf.

  1. ↑ HBV Vol. 9. (1994) p. 423
  2. ↑ HBV Vol. 9. (1994) p. 426
  3. ↑ Mebs, Scherzinger, 2000, p. 270
  4. ↑ a b c d König, Weick, 2008, p. 485
  5. ↑ Mebs, Scherzinger, 2000, p. 278
  6. ↑ a b HBV Vol. 9 (1994) p. 426
  7. ↑ Aebischer (2008) p. 107
  8. ↑ König, Weick, 2008, pp. 202, 482, 484
  9. ↑ Pertti Saurola: Bad news and good news: population changes of Finnish owls during 1982-2007. In: ARDEA 97 (4): 469-482
  10. ↑ König, Weick, 2008, pp. 486–487
  11. ↑ Stock situation in Great Britain and Ireland. (PDF; 29 kB)
  12. ↑ Hölzinger (2001) p. 236
  13. ↑ Thomas Rödl, Bernd-Ulrich Rudolph, Ingrid Geiersberger, Kilian Weixler, Armin Görgen: Atlas of the breeding birds in Bavaria. Distribution 2005 to 2009 . Verlag Eugen Ulmer, Stuttgart 2012, p. 122
  14. ↑ seaturtle.org
  15. ↑ Mebs, Scherzinger, 2000, p. 284
  16. ↑ a b Wiggins, Holt, Leasure: Migration . 2006
  17. ↑ HBV Vol. 9. (1994) pp. 435-436
  18. ↑ HBV Vol. 9 (1994) p. 436
  19. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas, Volume 9. Columbiformes - Piciformes. Aula-Verlag, Wiesbaden 1980, p. 435
  20. ↑ Wiggins, Holt, Leasure: Habitat . 2006
  21. ↑ Hölzinger (2001) p. 241
  22. ↑ Hölzinger (2001) p. 242
  23. ↑ Mebs, Scherzinger, 2000, p. 272
  24. ↑ Wiggins, Holt, Leasure: Territoriality . 2006
  25. ↑ Wilson Bull., 105 (3), 1993, pp. 497-503 (PDF; English; 323 kB)
  26. ↑ Wilson Bull., 105 (3), 1993, pp 490-496. pdf, engl
  27. ↑ a b c Wiggins, Holt, Leasure: Food Habits . 2006
  28. ↑ HBV Vol. 9 (1994) pp 449 and 450
  29. ↑ Raptor Research 32 (2): 111-115 (1998) (PDF; English; 611 kB)
  30. ↑ Pablo Teta et al. : Loxodontomys micropus (Rodentia: Cricetidae) . In: Mammalian Species 837: 1-11
  31. ↑ Raptor Research 35 (1): 68-69 (2001) (PDF; English; 207 kB)
  32. ↑ HBV Vol. 9 (1994) p. 451
  33. ↑ HBV Vol. (1994) p. 445
  34. ^ Clark, RJ: A field study of the short-eared owl, Asio Flammeus (Pontoppidan), in North America . Ed .: Wildlife Monographs. 1975.
  35. ↑ HBV vol. 9. p. 444
  36. ↑ Mebs, Scherzinger. 2000, p. 279
  37. ↑ Mark Vukovich, Gary Ritchison: Foraging Behavior of Short-eared Owls and Northern Harriers on a Reclaimed Surface Mine in Kentucky . In: Southeastern Naturalist 7 (1): pp. 1-10; 2008
  38. ↑ Condor 62: 6 (1960) p. 486. (PDF; English; 149 kB)
  39. ↑ Mebs, Scherzinger, 2000, p. 274
  40. ↑ Mebs, Scherzinger, 2000, p. 276
  41. ^ Donald S. Heintzelman: Hawks and Owls of Eastern North America. Rutgers University Press, 2004, ISBN 0-8135-3350-3 , p. 66.
  42. ↑ Mebs, Scherzinger, 2000, pp. 280-281
  43. ↑ Hölzinger (2001) p. 244
  44. ↑ HBV Vol. 9. (1994) p. 441
  45. ↑ Wiggins, Holt, Leasure: Breeding . 2006
  46. ↑ Hölzinger (2001) p. 246
  47. ↑ a b Hölzinger (2001) p. 247
  48. ↑ The Auk 79 (1959) p. 222 f. (PDF; English; 575 kB)
  49. ↑ a b HBV Vol. 9. (1994) p. 442
  50. ↑ Wiggins, Holt, Leasure: Demography and Populations . 2006
  51. ↑ Euring sheet (Engl.)
  52. ↑ Handbook of the Birds ...
  53. ↑ data sheet Birdlife international (engl.)
  54. ↑ Data sheet Birdlife europe (PDF; Engl.)
  55. ^ ML Oparin: Recent Fauna of Ground-Nesting Birds in Transvolga Steppes and its Dynamics in the 20th Century . In: Biology Bulletin, 2008, Vol. 35, No. 4, pp. 422-427. © Pleiades Publishing, Inc., 2008. ISSN  1062-3590
  56. ↑ fs.fed.us (PDF file; 1.8 MB)
  57. ↑ Thorsten Krüger (2018): Short-eared Owls (Asio flammeus) as breeding birds in hay meadows: Endangerment and protection. Vogelwelt 139: 183-201.
  58. ↑ Christoph Grüneberg, Hans-Günther Bauer, Heiko Haupt, Ommo Hüppop, Torsten Ryslavy, Peter Südbeck: Red List of Germany's Breeding Birds , 5 version . In: German Council for Bird Protection (Hrsg.): Reports on bird protection . tape 52 , November 30, 2015.

Web links

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Wiktionary: Short-eared Owl  - explanations of meanings, word origins, synonyms, translations