jay

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jay
Eurasian Jay (Garrulus glandarius)

Eurasian Jay ( Garrulus glandarius )

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Corvoidea
Family : Corvids (Corvidae)
Genre : Garrulus
Type : jay
Scientific name
Garrulus glandarius
( Linnaeus , 1758)

The Jays ( Garrulus glandarius ) is a songbird from the family of corvids (Corvidae).

It is distributed over Europe, parts of North Africa and the Middle East as well as in a broad belt through Asia and there southward to Indochina. It breeds in light, structured forests of all kinds, but in Central Europe prefers mixed and deciduous forests. Its food spectrum is very diverse, with animal food predominating in the summer half-year and vegetable food in the winter half-year. Before winter, extensive stocks of acorns and other nut fruits are created.

South and West European jays are mostly resident birds , Central, East and North European partial migrants , whereby only a few northern populations completely clear their breeding areas in winter. In some years there are extensive evasions of northern and eastern European populations.

description

Appearance

The feathers in the area of ​​the wing , hand covers and large arm covers have a blue-black banded outer flag.
Jay head
The white rump is particularly noticeable in the flying bird.
View of the jay's belly and spread wings
Jay taking a bath

With a body length of 32 to 35 cm, the jay is one of the medium-sized corvids, its wingspan is around 53 cm and its weight is around 170 grams. The strong beak is gray-black to black. The feet are gray-brown to brown flesh-colored with yellowish or whitish soles. The iris is bluish-gray with a reddish inner and outer ring and fine mottling.

The sexes do not differ in the plumage color. The head is more or less conspicuously drawn depending on the subspecies. The nominate form G. g. glandarius , which occurs in Central, Eastern and Northern Europe, shows white areas on the forehead and vertex, the narrow, elongated feathers of which are black-striped and which can be set up as a hood when excited. The region around the eye is also white with black dashes, often with the exception of the anterior ear covers. Also noticeable is a clearly separated, black stripe of beard, which is about the size of the beak. The chin and throat are white. The back of the ear covers, the sides of the neck and the nape are reddish beige to matt fox-colored. This coloration continues on the back, shoulders and underside, where it tends to turn greyish-brown on the back and a little lighter on the underside. The middle of the abdomen and the underside of the tail are white , like the back and rump . The latter feature is often clearly noticeable, especially in flight, and contrasts with the black-brown color of the control feathers . Their base is gray with a gray-blue transverse banding, which, however, is covered by the upper tail covers. The tail ends with a relatively straight edge.

The round, broad wings are striking and characteristic. The beige-pink color of the upper side is continued on the marginal coverts and the central arm coverts. Hand blankets, wings and large arm blankets are black on the inside flag and have black straps on the outside flag on a sky-blue background. This colorful plumage, which forms a bright blue field below the shoulder of the sitting bird, is a particularly characteristic species feature. The hand wings are dark brown with a light border, which increasingly carries a blue-black cross banding towards the inner hand wings. The arm wings are black-brown with a white outer flag towards the spring base. When the wing is folded, these form a white field and can also be clearly seen in flight. Sometimes there is a mostly invisible blue-black banding in the white areas. In addition to the brown-black umbrella feathers, several arm wings show a maroon color with a broad, black end border.

The youth dress is similar to the dress of adult birds, but is a little darker overall, the underside more reddish. The black stripes on the hood are less strong and the black and blue banding on the wings is less fine-grained. The beak is brown-gray, the feet pale brownish flesh-colored to gray-brown. The color of the iris is light brown-gray to gray-blue.

voice

The alarm call is a loud, rough and characteristic rattle ( audio sample ? / I ). The more common call is dchää-dchää and sometimes a buzzard-like , pure piüü can be heard. The singing is quietly babbling. The jay is able to imitate the voices of other birds or sounds. Audio file / audio sample

behavior

The diurnal jay usually behaves very inconspicuously during the breeding season, but is noticeable due to its pronounced, loud warning behavior. Outside of the breeding season, you can often see it in small, scattered groups, pulling or looking for food. The flight of the species is very characteristic and conspicuous. It looks slightly awkward due to the irregular flapping of its wings and in which the conspicuous coloring comes into its own. Usually only short distances are flown over and the cover of forest edges and bushes cleverly exploited, with other birds in a flock usually following at a considerable distance. In the forest, the bird flies very skillfully and agile even in closed stands. On the ground and in the branches, it usually moves hopping, often with the tail spread open for a short time.

distribution

Brood distribution of the jay

The jay is native to large parts of the Palearctic and Oriental . It colonizes all of Europe, where there are only gaps in distribution in the north of the British Isles and Scandinavia, as well as on the Iberian Peninsula . In the Mediterranean , it also populates the Atlas region in North Africa, the eastern edge of the Mediterranean to the north of Israel and Asia Minor. There is a larger gap in the middle here. To the east, it spreads to the Crimea , the Caucasus region and the mountainous regions of Iran and Iraq . North of the Black Sea , the distribution extends through the deciduous forest zone and the southern taiga to Sakhalin , Korea and Japan and extends in an East Asian arm that includes large parts of China, south to Indochina and west to the Himalayas .

hikes

Eurasian jay in winter

The jay is a partial migrant whose migration behavior is quite complex and to Evasionen tendency that sometimes only local or regional, in a few years but also very spectacular, large-scale proportions may have.

The southern and western European populations are predominantly standing or mooring birds . The birds of Central, Eastern and Northern Europe are partial migrants, with birds from the region of the boreal coniferous forests largely leaving their breeding areas in winter. The species shows characteristics of a real migratory bird with a largely fixed migration phenology and the mostly uniform migration direction to the southwest . In many parts of Europe - presumably due to this disposition and as evidenced by ring finds - individual birds regularly move away in a south-westerly direction, but this is hardly registered due to the overlapping of other migratory movements. The distance covered is usually less than 100 km. Otherwise, there is often a local dispersion move in autumn, partly triggered by weather conditions , in which, however, usually no uniform direction of movement can be determined.

In the case of larger evasions, the predominant direction of migration is usually southwest-west. The reason for these migratory movements is evidently not due to a lack of food, because they also occur in years with a rich supply of food. Instead, follow larger Evasionen firstly on year with particularly good breeding success and correlate secondly to the mast cycle of various nut fruit -bearing trees like stalk and sessile oak and partly of European beech . In some years all of these species may experience reduced fruit set, making it difficult for the jay to build winter supplies. Apparently the evasions are particularly pronounced in these years. The frequency of the years in which large-scale evasions were recorded is not a regular one. In northern Central Europe they fell in the years 1882, 1898, 1916, 1932, 1933, 1936, 1947, 1955, 1964, 1972, 1977 and 1983. In 1964, for example, 35,000 migratory birds were counted in Danzig within a month, the largest Swarm consisted of 1682 copies.

The Eurasian jay avoids larger open areas and especially water surfaces when it moves. It usually flies around these and follows coastlines and shorelines or the edges of large forest areas, which can sometimes lead to significant distractions from the direction of migration.

The autumn migration - both with the usual migration or dispersal, as well as with evasions - in Central Europe usually begins in the second decade of September, exceptionally as early as the beginning of September or the end of August, reaches its peak in the second half of September and is usually completed in mid-October. The return home usually takes place in March and is often much less pronounced than the departure. Evasion birds often migrate later in April and May, and migrating birds were sometimes found in June.

Geographic variation

Eurasian jay, subspecies G. g. albipectus
The subspecies G. g. atricapillus in Israel
The subspecies G. g. japonicus
Representation of the subspecies G. g. leucotis

The jay shows a very pronounced geographic variation. Almost 70 subspecies are sometimes described, 34 of which are listed here that are largely recognized. These can be divided into eight subspecies groups. They are either geographically isolated or linked by intermediate populations. Within the subspecies groups, the variation in characteristic features is mostly clinically pronounced.

glandarius group

This subspecies group, to which the nominate form belongs, colonizes Europe to the Urals and south to the Mediterranean region. It is reddish gray-brown in color and shows a dashed skull.

  • G. g. glandarius (Linnaeus, 1758) - Northern and Central Europe eastwards to the Urals
  • G. g. hibernicus Witherby & EJO Hartert , 1911 - Ireland
  • G. g. rufitergum E. JO Hartert , 1903 - Central and southern Scotland, England, Wales and north-western France
  • G. g. fasciatus ( AE Brehm , 1857) - Iberian Peninsula
  • G. g. albipectus O. Kleinschmidt , 1920 - Italy, Sicily and the Dalmatian coast
  • G. g. ferdinandi Keve-Kleiner , 1943 - Eastern Bulgaria and adjacent areas in northern Thrace
  • G. g. graecus Keve-Kleiner , 1939 - Western Balkans and mainland Greece
  • G. g. cretorum R. Meinertzhagen , 1920 - Crete
  • G. g. corsicanus Laubmann , 1912 - Corsica
  • G. g. ichnusae O. Kleinschmidt , 1903 - Sardinia
  • G. g. glaszneri Madarász , 1902 - Cyprus

cervicalis group

This group is common in northwestern Africa. The top is two-tone: the top of the head and partly also the neck are red-brown, wine-red or black, with the top of the head being broadly dashed. In contrast, the back is gray.

atricapillus group

This group inhabits the eastern Mediterranean and Asia Minor, as well as parts of the Caucasus region and the Crimea. The subspecies show a black skull with an elongated hood and an extended white forehead. The neck and back are uniformly colored. On the European side of the Bosporus there is a mixed population with the subspecies G. g. graecus .

hyrcanus group

This group includes only the subspecies of the same name, which colonizes the northern flank of the Elburs Mountains and is characterized by a hybrid population with the subspecies G. g. krynicki is connected. The forehead and bonnet are black, but the latter shows feathers with reddish edges.

brandtii group

This group inhabits northern Russia to northern Japan and is recognizable by a fox-red or red-brown head with a dashed upper head. The rest of the upper side is grayer than that of the glandarius group. There are mixed populations with the latter as well as with the Asian bispecularis group.

bispecularis group

This group is widespread from the Himalayas to China. The top of the head is not dashed, the head and back are uniformly colored. The white mirror on the arm wings has been replaced by a blue, black and white sparrow mark.

  • G. g. bispecularis Vigors , 1831 - Western Himalayas eastward to western Nepal
  • G. g. sinensis Swinhoe , 1871 - Central South, South and East of China and Northern Myanmar
  • G. g. interstinctus E. JO Hartert , 1918 - eastern Himalayas, southern Assam and southeastern Xizang
  • G. g. oatesi Sharpe , 1896 - Northwestern Myanmar
  • G. g. haringtoni Rippon , 1905 - Western Myanmar
  • G. g. taivanus Gould , 1863 - Taiwan

leucotis group

Only the eponymous subspecies is in this group. It is characterized by a black hood and a double blue-black-white wing mirror.

  • G. g. leucotis Hume , 1874 - Central and Eastern Myanmar, Southern China (Southern Yunnan ), Thailand, and Central and Southern Indochina

japonicus group

This subspecies group colonizes Japan with the exception of Hokkaidō. She wears a black rein, which is connected with a wide black stripe of beard. The crown of the head and bonnet are black with feathers edged with broad white. The outer flags of the outer arm wings are very extensive white.

habitat

The jay colonizes deciduous , mixed and coniferous forests in Central Europe during the breeding season . It is preferred in sparse stands with a rich lower layer of trees or a high layer of shrubbery , or in richly structured forests in which different age groups, clearings, seals or fields alternate over small areas. In monotonous forest forms such as spruce or pine forests, but also for example beech hall forests, it occurs in low density, only in peripheral areas or in the area of ​​clearings and fields.

In corresponding forest-like habitats, it also breeds near settlements, for example in parks, extensive gardens or in cemeteries. In the open landscape, the jay is rarely found during the breeding season. When the fruit ripens after the breeding season, however, it specifically looks for individual oaks or hazel bushes in the open landscape.

In the Mediterranean region and Asia Minor, the jay inhabits wooded slopes, dry forests, mountain forests, pine stands, olive groves and other plantations. Here, too, it sometimes occurs near the city. In the Scandinavian coniferous forest zone, particularly nutritious forest locations are settled, preferably pine-spruce forests with the highest possible proportion of spruce. In Siberia the species apparently lives mainly in coniferous forests. In the Caucasus region and in China, a preference for oak forests can be seen, while in other regions of Asia no preference can be found. In the tropical regions of South Asia it inhabits dry, subtropical forests, mountain forests, open jungles and Indaing forests .

The altitude distribution is very different locally and apparently mostly dependent on suitable habitats. In the European mountains it settles at altitudes between 900 and 2000 m, in the Himalayas it is found at altitudes of up to 3300 m. In some mountains it is completely absent, sometimes it can only be found on slopes facing south.

Space requirements and settlement density

The jay inhabits a territory all year round, the boundaries of which are not precisely defined and from which only the immediate vicinity of the nest location is really defended during the breeding season. The area size is usually between 2 and 10 hectares, whereby the space requirement and the individual radius of action can vary greatly even during the breeding season. In the open landscape, the jay sometimes breeds in small woody trees from 0.75 ha in size. The minimum nest distance was 100 m.

In a telemetry study in southern Sweden, it was found that the size of the action space varies depending on the habitat quality and best habitats to 25, in less favorable is 40 hectares. Another study there showed that the average size fluctuates only slightly between the pre-breeding season and the breeding season. In Tuscany, the area of ​​action fluctuated between 5.5 and 83.2 ha in April, and between 42.5 and 358.8 ha from July to November - i.e. during the main collection period.

The settlement density is relatively difficult to determine in this species, as it behaves quite secretly during the breeding season, which can lead to inaccuracies in the recording. For Central Europe, the average values ​​in forest areas are mostly just below one breeding pair per 10 ha. The maximum values ​​rarely exceed 1.5–2 breeding pairs per 10 ha. In favorable habitats they are around 2–4 bp./10 ha, exceptional values ​​of 5–8 bp./10 ha are sometimes reached after years of invasion. The large-scale settlement density in the cultural landscape is usually less than 1 breeding pair per km².

nutrition

Significant supplies of acorns are gathered before winter.
Jay with a captured songbird nest

Food spectrum

Eurasian jay with corn kernels
(in winter at a feeding ground for wild birds)

The food spectrum of the jay is very extensive, whereby the seasonal offer is mostly used. From spring to autumn, therefore, the proportion of animals predominates, which is partly due to the availability and partly due to the fact that the nestlings are mainly supplied with animal food. In late autumn and winter, the vegetable content increases sharply. This consists to a large extent of supplies that are created all year round, but mainly before winter.

Acorns are preferred as vegetable food, but other nut fruits such as beechnuts, hazelnuts and sweet chestnuts are also used. If these are not available in sufficient quantities, crops of a similar nature, such as maize in particular , but also grain and buckwheat, are used . In Eastern Europe in particular, increased use of maize was observed during acorn shortage years. In addition to this main diet, numerous tree seeds, nuts, berries and stone fruits , pome fruits , legumes and potatoes , mushrooms , buds or plant galls are also eaten on occasion . Fruit is apparently also used as nestling food when the insect supply is poor.

Animal food includes mainly caterpillars of butterflies and sawfly as well as beetles. Caterpillars and white grubs play a role especially during the breeding season and as nestling food. With mass reproduction of certain species, the offer is often used extensively and at times almost exclusively. In midsummer, locusts are often preyed on the edges of the forest . As a food supplement, spiders and other arthropods are usually added in much smaller proportions .

Smaller vertebrates are also part of the diet, whereby carrion is sometimes eaten in addition to self-captured animals. Prey includes small reptiles and mammals up to the size of young rabbits . Also nests , nestlings and young small birds until shortly after leaving nest count for food spectrum. The proportion of food that eggs and birds make up is usually small, the latter are probably mainly captured when young birds that are almost fully fledged are to be fed. However, in rare cases there are apparently individuals who have specialized in nest predation and who take advantage of the hatred reactions of other songbirds in finding nests.

Despite the wide range of food, the jay is often picky. The taste of the food is apparently mostly tested with the tongue before consumption. Sticky food or hairy insects, for example, are often rejected. The jay consumes strikingly colored insects at most very suspiciously and cautiously, but it also eats spiked insects with a prickly device. Amphibians are evidently spurned because of their secretions, worms and snails only accepted as food by a few individuals.

Food acquisition

During the breeding season, the foraging takes place mainly in the treetops. In the period when vegetable food predominates, it is collected in trees and bushes as well as on the ground. The jay often hunts on foot, rummages through the fall foliage, pokes its beak in crevices and between tree roots or looks for food behind the bark of trees. Animal droppings and human waste are also searched. When hunting insects, a type of flight hunt that is reminiscent of that of the shrike has been observed .

The jay has sometimes been observed to parasitize other species. For example, he drives woodpeckers away when they are looking for food in order to acquire their feeding places, or he makes use of squirrels' extensive food depots . One couple has been reported to steal prey from a kestrel nest.

The jay is quite adept at processing food, especially hard-shelled fruit. Solid objects are usually handled with the beak, if this is not successful, also with the help of the toes. Acorns are usually bitten open with the beak, levered open, peeled in a rotating motion, less often chopped up. Sometimes they are held with the inner toes while the others grip the seat. Sometimes the unripe acorns are already being picked from the trees.

Stock keeping

The jay builds deposits of excess food all year round. He does not begin to collect acorns and other nut fruits until they are ripe in August, which can continue into early winter and sometimes into next spring. At the peak of October, the bird often spends 10 to 11 hours a day collecting. For this purpose, large stretches of 5 to 8 km are covered, for example to look for fruiting oak stands or individual trees. Usually the distances are shorter. On longer collective flights, around 5 to 7, sometimes up to 10 acorns are collected in the throat and transported to their own territory. There is also space in the beak for another acorn. The bird prefers to hide the acorns on structured surfaces at forest edges and clearings. The fruits are hidden individually, less often in twos or threes, in the litter, in holes and crevices, in the vegetation or on tree roots, driven in with a few blows of the beak and then roughly covered. When finding supplies again, the jay orientates itself on the conditions in the landscape, so that it can find it with astonishing accuracy even under a higher snow cover. During an investigation in Saxony-Anhalt , it was determined that a single jay stores up to 2200 acorns, i.e. around 11 kg of supplies, for the main collection period, which lasts around 20 days. This was extrapolated to around 3000 acorns or 15 kg per bird for the entire collection period. Other studies came to 4600 to 5000 acorns per bird. The stocks are mixed around a week after the collection period and some of them are even fed to older young birds in the following year. Presumably only a small percentage is actually used, which means that the jay contributes to the spread of oak seedlings.

Reproduction

Eurasian jays are monogamous seasonal marriages and annual broods. If the clutch is lost, additional clutches occur. Young jays are likely to be sexually mature as early as the first year, but a large part does not breed until the second year.

Territorial behavior

In Central Europe, the jay spends the whole year in a territory whose boundaries are only relatively roughly defined and which is only defended during the breeding season. Outside the breeding season, the species tends to be gregarious, but even during the same period, the territory is only defended against obvious rivals. Other, subdominant birds are often tolerated.

The territory delimitation and the choice of nesting place are made for resident and migratory birds from February, for migratory birds immediately after their return, which can sometimes be quite late.

Spring meetings

As with other raven bird species, the jay often has ceremonial gatherings in spring, which are particularly frequent and noisy with this species. They consist of 3 to 30, more rarely up to 50 birds and can be observed from March, sometimes until mid-May or into June. Sometimes they emerge within troops moving home. Birds that have already been mated take part in this or ignore the drift, which, however, has so far only been ascertained through observations on aviary birds.

The gathering begins with loud, communal pursuit flights that can run in a straight line, in a zigzag or in a circle. It is noticeable that the birds move with strangely short flaps of their wings. In the following, the entire group invades a treetop or some other exposed place and is then divided into pairs or small groups that chase each other over short distances, hopping or flying. A number of vocalizations can be heard that cannot be heard on other occasions, such as a räh-räh , a deep kroi-kroi and various types of whistling and chattering sounds. After a while all birds fall silent and sit opposite each other in pairs or groups. The birds appear strangely thin-necked by laying on and ruffling certain parts of the plumage. Soon afterwards the congregation dissolves and the individual birds go back to their daily business. The meaning of these gatherings is not entirely clear, but since they are often concluded with a copula, they probably have a sexual meaning or are used to find a partner. It was also assumed that they should bring about the synchronization of breeding behavior or the reorganization of the territorial boundaries.

Nest building

Jay and nest (in Nederlandsche Vogelen , 1770)
Brooding jay (April 2015 in Upper Franconia )

The nesting place is mainly chosen by the male. Preferred locations are in the tops of the lower tree layer, such as undergrowth or poles, less often in bushes. Most of the nests were found at heights between 1.5 and 8 m. In exceptional cases there were nests at a height of 30 m or ground broods. The nest is well hidden in the dense branches, whereby the choice of nest trees is mostly due to the composition of the respective forest area. Sometimes there may be local preferences. In some places the jay likes to breed in spruce and fir thickets, presumably an adaptation to predation by hawks and sparrowhawks . Occasionally, old nests are accepted by other birds such as the buzzard or magpie, and more rarely broods take place in half-caves or nesting boxes. Some nests have been found on human buildings.

The nest, in the construction of which both sexes participate, consists of twigs and fresh twigs on the outside, which become finer towards the top and towards the nest hollow. Sometimes earth is also built into this layer. The inner layer consists of fine branches of deciduous trees, the nest hollow is lined with stems, grass or fibers. At the bottom of the hollow there are moss, leaves, roots and bark, at the edge it is padded with fine material such as feathers, hair, threads. The outer diameter is between 16 and 40 cm, the nest height between 8.5 and 26 cm. The hollow is between 5 and 9.5 cm deep.

Clutch and incubation

Jay's eggs

The jays usually lay their eggs later than other corvids . This usually only takes place when the leaves are completely covered, so that the point in time can fluctuate by up to three weeks from year to year. It lies in Central Europe between mid-April and early May.

The clutch consists of 4 to 7, more rarely 8 and a maximum of 10 eggs. They are oval to short or pointed oval and measure an average of about 31 x 23 mm. They show little or no luster and are very finely speckled from light brown to green-brown on a light background, which can be greenish, brownish or sand-colored. The speckles can be very dense and evenly distributed or appear washed out, so that the eggs appear monochrome.

The eggs are laid every 24 hours and incubation takes place from the third or fourth egg. It lasts between 16 and 17 days, rarely longer.

Young bird

Rearing boys

The young usually hatch within 24 to 30 hours, the nestling period lasts 20 to 22 days. After leaving the nest, the young are fed for another 3 to 4 weeks.

Breeding success and age

During the egg-laying phase, the eggs are often lost by squirrels , dormice , magpies or other jays. With the incubation and the time at which the canopy is fully closed, the probability of losses decreases.

The maximum age recorded for jays in both freedom and captivity was 17 years.

Inventory development

In Europe in particular, there have been various large-scale or regionally pronounced, long-term changes in the population that have quite different causes.

In past centuries the jay was persecuted as an alleged forest pest and potential nest robber of hunted bird species and the hunt was supported by premium payments - in some cases until the 1880s. The jay was therefore almost wiped out locally. At the beginning of the 20th century, the pressure of persecution eased considerably. This became noticeable as a significant recovery from the 1920s.

Along with the population recovery, a tendency towards urban expansion was observed, which began particularly in the 1920s and 1930s and reached its peak between the 1950s and 1970s. In more eastern regions of Europe such as Poland or the Baltic States, this development did not take place until later; it only reached Russia in the 1990s. This trend has now subsided in Central and Western Europe and the jay has largely disappeared from the cities as a breeding bird.

At the same time as this trend, the jay was able to greatly expand its northern area boundary in Scandinavia as a result of global warming from the 1920s, even if the settlement densities usually remained lower in areas north of the deciduous forest zone. In the West Siberian subspecies G. g. brandtii has been expanding its area to the north since the last decades of the 19th century.

The elevation spread in some mountains was also influenced by the warmer climate, for example in western Sayan . In Central Europe, the reason why the Eurasian jay now often breeds in higher altitudes lies in the increased structuring of the mountain forests through logging. In Scotland, however, afforestation was one reason for the extension of the area boundary to the north.

The population in Europe was estimated at around 6 to 13 million breeding pairs in 2004, which - including non-breeders - would correspond to around 18 to 39 million individuals. The world population would then be extrapolated between 36.7 and 156 million birds. There are no reliable figures on this.

Naming

Illustration from the bird book by Jodocus Oesenbry, 1575

In addition to the name commonly used today as “jay”, numerous other trivial names have been used. These include name combinations from different spellings of “Häher” (for example Heyer, Heger, Hehr ) and attributes such as acorn, forest, wood, mirror, tree or nut . Sometimes the component -jay is replaced by -raven, -mopster, -crow, -bird, -screier or the like. Many of the names are onomatopoeic and imitate different calls such as Gäckser, Tschäcker, Jägg, Gäbsch or Gräcke . As in English ( Jay ), this is also the case in many other languages. Often the species is also referred to as a Markwart (also Markolf , Marquard (t) or similar) as well as a Herold with regard to its warning behavior .

Others

Due to its storage and the incomplete use of these depots, the jay ensures the spread of numerous tree species. In Central Europe this mainly affects English oak and sessile oak , but also beech and hazel . Those established by Jay, tree stands are in forestry as Hähersaaten designated.

Star and jay "embed" - d. H. They sit on wood ant hills with their plumage on their bristles and "bathe" in the formic acid sprayed by the ants that were alerted . This is supposed to drive parasites out of the plumage.

literature

Web links

Commons : Jay  - Album with pictures, videos and audio files
Wiktionary: Jay  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ^ Andrén (1985) and Nilsson (1985) cited in Glutz v. Blotzheim, pp. 1402f, s. literature
  2. ^ Zajac (1995) in Glutz v. Blotzheim and Tomiałoc (1990) in Bejćek u. Gorban, s. literature
  3. ↑ a b c Keve, pp. 27f, s. literature
  4. ↑ Glutz v. Blotzheim, pp. 1408f, s. literature
  5. ↑ Glutz v. Blotzheim, p. 1410, p. literature
  6. ^ Andrén (1990) in Glutz v. Blotzheim, p. 1410, p. literature
  7. ^ Grahn (1990) in Glutz v. Blotzheim, p. 1410, p. literature
  8. ↑ Rolando et al. (1991 and 1990) in Glutz v. Blotzheim, p. 1410, p. literature
  9. ↑ Glutz v. Blotzheim, p. 1410f, s. literature
  10. ↑ Glutz v. Blotzheim, p. 1430f, s. literature
  11. ↑ Keve, p. 40, p. literature
  12. ↑ Glutz v. Blotzheim, p. 1419, p. literature
  13. ↑ Wadewitz (1976), quoted in Glutz v. Blotzheim, p. 1422f, s. literature
  14. ↑ Glutz v. Blotzheim, p. 1423, p. literature
  15. ↑ Glutz v. Blotzheim, p. 1425f and D. Goodwin 1951, p. 425f (see literature)
  16. ↑ a b Bejćek u. Gorban, s. literature
  17. ↑ a b c Glutz v. Blotzheim, p. 1414f (see literature) and C. Harrison, P. Castell, H. Hoerschelmann: Young birds, eggs and nests of birds - Europe, North Africa and the Middle East , Aula Verlag, Wiebelsheim 2004, ISBN 3-89104- 685-5
  18. ↑ a b Glutz v. Blotzheim, p. 1416f (see literature)
  19. ↑ a b c Glutz v. Blotzheim, p. 1397, p. literature
  20. ↑ Glutz v. Blotzheim, p. 1409 and Bejćek u. Gorban, s. literature
  21. ↑ Birdlife Factsheet and IUCN (see web links)
  22. ↑ In the Südmärkischen and in the Elbe-Elster-area, as well as in the West- and Nordmeißnischen: Holzschreier, whereby wood stands here generally for forest. According to Günter Bergmann: Small Saxon dictionary . Bibliographical Institute, Leipzig 1989.
  23. ↑ Keve, pp. 25f.
  24. ↑ Birds love to bathe ...