Gray bunting

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Gray bunting
Gray bunting (Emberiza calandra)

Gray bunting ( Emberiza calandra )

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Passeroidea
Family : Bunting (Emberizidae)
Genre : Ammern ( Emberiza )
Type : Gray bunting
Scientific name
Emberiza calandra
Linnaeus , 1758

The Corn Bunting ( Emberiza calandra , Syn. : Miliaria calandra ) is a bird art from the family of the buntings (Emberizidae). This bunting colonizes large parts of the southwestern Palearctic from the Canary Islands, northwestern Africa, Portugal and Ireland eastward to southwestern Iran and Kazakhstan . The gray bunting inhabits open landscapes with individual trees or bushes and at least partially dense ground vegetation, in Central Europe mainly extensively used grassland, field margins and fallow land. Depending on the distribution , the species is partial , short-distance or medium- distance migrant .

The stock in north-western and central Europe collapsed dramatically in some cases between the 1960s and 1980s; after 1990 an increase was observed in parts of Europe, but a further decrease in other parts, the reasons for which are primarily changes in agricultural use. Overall, the world population is considered to be declining, but the IUCN still classifies the gray bunting as harmless (“least concern”) worldwide . In the 2015 Red List of Breeding Birds in Germany , the species is on the pre-warning list.

Gray bunting
Gray bunting in the Lower Oder Valley National Park

description

Gray bugs are very large, strongly built bunting with a rather large head, strong beak and medium-long tail. Overall, they are quite a monochrome brownish color and have no noticeable markings. The sexes are colored the same, but males are on average significantly larger and heavier than females.

With a body length of 16 to 19 cm and a weight between 32 and 67 g, the species is the largest bunting in the western Palearctic and larger and considerably heavier than a goldhammer . Males caught in the Swiss Plateau between March and October had wing lengths of 96.0 to 106.0 mm, on average 101.5 mm and weights of 45.0 to 62.0 g, females had wing lengths of 87.0 to 95.0 mm, on average 91.6 mm and weights from 38.0 to 55.5 g.

In adult birds, the back, shoulder feathers, rump, and upper tail-coverts are gray-brown to medium-brown. For this reason, the front back and shoulder feathers are dashed in strong black-brown. The rear back and rump can be dotted just as strongly as the front back, but the dotted lines can also be light brown and are then hardly noticeable. In the fresh plumage, the lateral upper tail-coverts in particular can have whitish lace edges.

The upper side of the wing is also predominantly medium brown. The medium and large arm covers show wide, light brown hems in their fresh plumage, which increasingly fade and thus become more noticeable. The wings of the hand have a narrow, light beige hem on the outer flag, the outer flags of the wings are wider and lined with a warmer brown color. The gray bunting shows no white on the outer edges of the tail. The middle brown control feathers are lined with light beige on the outside and inside, these seams become wider towards the tip of the feather. The underside of the trunk is light beige to dark gray beige and dark dashed to varying degrees.

There are also no striking drawings on the head; the head, like the back, is gray to medium brown. The top of the head is fine, dark dashed, the indistinct stripe above the eyes is light beige. The throat and sides of the neck are also light beige, the chin stripe is gray-brown to medium brown.

The iris is deep dark brown. The bill is yellowish horn-colored, the ridge of the beak is dark horn-brown. The legs are yellowish pink.

In the youth dress , the top is lighter, warm beige-brown without gray tones. The crown of the head is dark, the middle crown of the head is usually sparsely striped dark, creating a 2 to 3 mm wide, light strip across the middle of the head. Shoulder feathers and upper wing coverts are deep brown with sharply contrasted light beige edges. After the full moult in autumn , the young birds can no longer be distinguished from adult birds.

Vocalizations

The singing, which is uttered exclusively by the male and can be heard almost all year round, is quite monotonous. It consists of a single, short and frequently repeated stanza without melodic elements, which lasts 1.3 to 2.5 seconds. The stanza is clearly in three parts. The first part consists of 3 to 10 very short, hard elements that are performed with increasing speed. This is followed by a trill-like part with 1 to 8 blocks of around 10 similar elements. The stanza ends with a crunching, rattling trill made up of 3 to 6 element sequences that the human ear can no longer perceive as individual sounds. The sound of this trill is compared to the clink of a bunch of keys. The stanza can be reproduced onomatopoeically like "tück tück-zig-zik-zkzkzkrissrisss" . Singing ? / iAudio file / audio sample

The singing is performed from an elevated singing tower with a clear panoramic view, preferably from telephone lines or low power lines, but also from the tips of individual bushes or trees, from fences, hay bales and similar structures.

Systematics

The systematic position of the gray bunting was long disputed. Karel Voous separated the bunting from the genus Emberiza in 1977 and placed it as the only species in the monotypical genus Miliaria C. L. Brehm in 1928. Voous justified this separation with the size, the beak structure, which differs from all other species of the genus Emberiza , the complete Juvenile moult and deviant behavior. Glutz von Blotzheim & Bauer agreed with this view and stated that the male's missing splendid dress , the missing white outer edges of the tail, the deeply forked tail, the short wings and the very simple singing were other features that occur only in the gray bunting .

As a result of several molecular genetic investigations of the DNA , a systematic special position of the gray bunting could not be confirmed. The bunting is therefore clearly to be assigned to the monophyletic genus Emberiza - including other previously monotypical genera . The sister taxon of the gray bunting is evidently the band bunting ( Emberiza fucata ), but this sister taxon ratio is not yet sufficiently secured.

In addition to the nominate form , only one other, poorly differentiated subspecies is usually recognized today:

  • Emberiza calandra calandra ( Linnaeus , 1758) - Largest part of the range. The nominate form is described above.
  • Emberiza calandra buturlini Johansen , 1907 - southeast of the distribution area from the Middle East to Central Asia. Lighter than nominate shape, upper side in the fresh plumage more olive gray, later more sand gray with lighter feather tips and edges, lower side whiter. Asian gray chambers are also less dashed on the throat and flanks.

distribution and habitat

Distribution areas of the gray bunting
(green = breeding areas, dark green = year-round occurrence, blue = wintering areas)

The gray bunting colonizes large parts of the southwestern Palearctic from the Canary Islands, northwest Africa, Portugal and Ireland east to the western edge of the Caspian Sea , further south and east the area then extends in two relatively narrow zones on the one hand to the southwest of the Iran and on the other hand as far as southeastern Kazakhstan . The northern limit of the distribution runs from the Shetland Islands over the northern tip of Denmark and the extreme south of Sweden to Estonia and Lithuania and then through southwest Russia and Ukraine to the northwestern edge of the Caspian Sea at around 43 ° N. The southern limit of the area becomes reached in the eastern Mediterranean on Crete , Rhodes and Cyprus, and in the Middle East in a narrow zone along the Mediterranean Sea in southern Israel . Further to the east, the southern limit of distribution follows roughly the southern border of Turkey and then extends to the Strait of Hormuz in western Iran . The gray bunting is considered to be a breeding bird originally restricted to the Mediterranean zone and the steppe zone , which was only able to spread to the north and west into the temperate and boreal zones through human agriculture.

The species inhabits open landscapes with individual trees or bushes and at least partially dense ground vegetation, in Central Europe mainly extensively used grassland, field margins and fallow land. In addition, dunes and heaths are also populated. In the Mediterranean area, the gray bunting is also found in abandoned olive groves and vineyards, in degraded, low-growing scrubland such as macchia , garrigue and mattoral , on burned areas, in light oak forests and near the coast on rocky dry slopes and in Salicornia steppes.

nutrition

Adult gray bunting feed primarily on cereal grains and the seeds of grasses, herbs and perennials. Depending on the weather and what is available, a wide range of invertebrates is also eaten, especially insects and their larvae and spiders. When the weather is good, nestling food consists almost exclusively of insects, spiders and, more rarely, small snails and other invertebrates; in bad weather, soft cereal grains and other plant seeds also play an important role. The foraging for food takes place mainly on the ground, in addition, the gray bunting also uses strong plant stems, for example to reach ears with its beak.

Reproduction and Age

Eggs of the gray bunting

Gray chambers do not show a clear pair bond. The males apparently primarily occupy and defend exclusive territories in order to be able to offer the females breeding places, and do not participate in nest building or in the incubation of the clutch and only to a small extent in the rearing of young. Females, on the other hand, unlike males, do not show any territorial behavior and do not pay attention to the territorial boundaries of the males, so the females often seek out areas in the territories of neighboring males to search for food for the offspring. The majority of breeding birds lead a monogamous brood marriage, but males are often polygynous . In two studies on North Uist and north of Liverpool, the proportion of polygynous males was 33 and 19%, respectively. The males are usually successively polygynous. Simultaneous polygyny is much rarer, however, in a study in Cornwall , a maximum of 7 females brooded in one male territory, 5 of them approximately synchronously. The criteria according to which the females choose a breeding site and thus a male has not yet been clearly clarified, at least in the investigation on North Uist the degree of polygyny was clearly correlated with the age of the males, i.e. older males had more females on average.

Gray bugs are ground breeders. The nest is built by the female away from woods in areas with closed and not too low ground vegetation and usually in such a way that the lower edge of the nest rests more or less on the ground. Higher nest systems are rare. The nests are quite large, loosely built structures, they have an outer diameter of 11 to 15 cm and a height of 6.0 to 10.5 cm. They consist mainly of blades of grass and mostly small amounts of other parts of the plant, with the material used becoming finer and finer from the outside in. The hollow is made with fine vegetable material, wool threads, animal hair and the like. Ä. Lined.

The gray bunting breed comparatively late. In Central and Western Europe, egg-laying begins at the end of April or beginning of May at the earliest; the main laying time falls from end of May to mid-June. The latest egg-laying takes place in July, exceptionally in early August. Second broods are not frequent, in two studies their proportion was less than 10% each. The clutch consists of 3 to 7, mostly 4 to 5 eggs, which have an irregular pattern of darker scribbles, dashes, dots and spots on a light beige, pale reddish brown or pale lilac background. The breeding season lasts 11 to 13, usually 12 to 12.5 days. As already described above, the eggs are only incubated by the female. Males also take little part, if at all, in feeding the nestlings, but accompany the female in foraging for food. The young birds leave the nest at 9 to 11 days and are then fed very variably for 20 to 33 days, then also in larger proportions by the male.

Sexual maturity is reached at the end of the first year of life. The maximum age proven by ringing is at least 10 years and 7 months for a gray bunting in the Czech Republic and 9 years and 10 months for a gray bunting in Spain.

hikes

Depending on the distribution , the species is partial , short-distance or medium- distance migrant . The breeding grounds are left with the end of the youngsters from July, but no later than August and September. The gray chambers then close in nutritionally favorable areas of the hatchery environment, e.g. B. on stubble fields or unharvested grain fields, together to swarms and then also form sleeping places. The sleeping places in Central Europe are in wetlands, often in reeds. The swarms and roosting communities of the gray chambers overwintering in the extended breeding area can consist of several hundred, rarely several thousand individuals in Central Europe.

The actual migration of migrating birds takes place between the end of September and the end of October. The wintering area extends only a little beyond the breeding area to the south and west, whereby climatically less favorable areas such as mountains and the Eastern European plains are mostly largely abandoned and climatically favored areas such as the plains near the coast and the Mediterranean area are brought in. Homewards were observed in Gibraltar from January to April. In Central Europe, the breeding grounds are occupied from the end of February to the beginning of May, depending on the weather, during which time the winter sleeping communities also dissolve.

Existence and endangerment

There is no reliable information on the world population. In Europe, the gray bunting is a very common breeding bird, for 2004 BirdLife International gave a rough estimate for the European population of 7.9 to 22 million breeding pairs. The main deposits in Europe are in the countries in the south-east and south-west, although the estimates here are particularly uncertain. Turkey has the largest population with 3 to 9 million pairs alone, followed by Spain with 1.4 to 4.3 million pairs in 1992 and Bulgaria with 0.8 to 2.5 million pairs.

The stock in north-western and central Europe collapsed dramatically in some cases between the 1960s and 1980s, the reasons for which are probably primarily changes in agricultural use. The species became extinct in Ireland at the beginning of the 21st century, and the UK population declined by about 75% between 1968 and 1991. In the Netherlands the population decreased from 1200 to 1250 pairs in 1975 to 60 to 80 pairs in 1991. For Schleswig-Holstein the population was estimated at 3000 to 4000 pairs around 1955, of which there were still around 70 pairs in the mid-1980s left free.

After 1990 an increase was observed in parts of Europe but a further decrease in other parts. In some cases considerable increases in the population were recorded in eastern Germany after 1990 due to large-scale set-aside in agriculture. For example, the species in Brandenburg was threatened with extinction around 1990, and around 2005 the population was again estimated at 8,000 to 15,000 pairs. Overall, the world population is considered to be in decline, but the IUCN still classifies the gray bammer as harmless (“least concern”).

swell

literature

  • E. Bezzel: Compendium of the birds of Central Europe. Passeres. Aula-Verlag, Wiesbaden, 1993. ISBN 3-89104-530-1 : pp. 727-732.
  • Urs N. Glutz von Blotzheim , Kurt M. Bauer: Handbook of the birds of Central Europe. Volume 14 / III: Passeriformes. Part 5: Embrizidae - Icteridae. Aula, Wiesbaden 1997, pp. 1857-1916.
  • J. Hoffmann, G. Haase: Grauammer - Miliaria calandra . In: ABBO 2001: The bird world of Brandenburg and Berlin . Nature & Text, Rangsdorf; 2001. ISBN 3-9807627-5-0 : pp. 619-622

Web links

Commons : Grauammer  - Collection of images

Individual evidence

  1. ↑ 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.
  2. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1864
  3. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1862–1863
  4. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1865–1876
  5. ^ Lars Svensson, Killian Mullarney, Dan Zetterström: Der Kosmos Vogelführer. Kosmos, Stuttgart 2011, ISBN 978-3-440-12384-3 : p. 402.
  6. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1902–1903
  7. ↑ Voous, KH: List of Recent Holarctic Bird Species, second ed. British Ornithologists Union, London 1977. Quoted in: PLM Lee, LJ Richardson & RB Bradbury: The phylogenetic status of the Corn Bunting Milaria calandra based on mitochondrial control-region DNA sequences. Ibis 143, 2001: pp. 299-303
  8. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1857
  9. ↑ PLM Lee, LJ Richardson & RB Bradbury: The phylogenetic status of the Corn Bunting Milaria calandra based on mitochondrial control-region DNA sequences. Ibis 143, 2001: pp. 299-303
  10. ^ A b Per Alström, Urban Olsson, Fumin Lei, Hai-tao Wang, Wei Gao, Per Sundberg: Phylogeny and classification of the Old World Emberizini (Aves, Passeriformes). Molecular Phylogenetics and Evolution 47, 2008: pp. 960-973
  11. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1859
  12. ^ Alan P. Peterson: Birds of the World - current valid scientific avian names. (Version 9.025 (2011-10-09)) - Emberizidae. ( Online , accessed December 17, 2011)
  13. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1857-1859
  14. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1891
  15. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1912
  16. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1905
  17. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1905–1907
  18. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1896-1897
  19. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1899
  20. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1897-1899 and 1910-1912
  21. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: p. 1894
  22. ^ Fransson, T., Kolehmainen, T., Kroon, C., Jansson, L. & Wenninger, T. (2010): EURING list of longevity records for European birds. online, accessed December 24, 2011
  23. ^ A b J. Hoffmann & G. Haase: Grauammer - Miliaria calandra . In: ABBO 2001: The bird world of Brandenburg and Berlin . Nature & Text, Rangsdorf; 2001: pp. 621-622
  24. ↑ Urs N. Glutz von Blotzheim, Kurt M. Bauer: Handbuch der Vögel Mitteleuropas , Volume 14 / III, Passeriformes (5th part): Embrizidae - Icteridae. Aula, Wiesbaden 1997: pp. 1888-1891
  25. ↑ a b Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004) Online as PDF
  26. ↑ E. Bezzel: Compendium of the birds of Central Europe. Passeres. Aula-Verlag, Wiesbaden, 1993. ISBN 3-89104-530-1 : pp. 728-729
  27. ↑ DT Parkin & AG Knox: The Status of Birds in Britain & Ireland. Christopher Helm, London 2010: pp. 375–376
  28. ^ RG Bijlsma, F. Hustings & K. (CJ) Camphuysen: Common and scarce birds of the Netherlands. (Avifauna van Nederland 2). GMB Uitgeverij / KKNNV Uitgeverij, Haarlem / Utrecht, 2001. ISBN 90-74345-21-2 : pp. 460-461
  29. ^ RK Berndt, B. Koop and B. Struwe-Juhl: Vogelwelt Schleswig-Holstein. Volume 5: Breeding Birds Atlas. 2nd edition, Karl Wachholtz, Neumünster 2003, ISBN 3-529-07305-9 : pp. 434-435
  30. ↑ T. Ryslavy, W. Mädlow & M. Jurke 2008: Red List and List of Breeding Birds of the State of Brandenburg 2008 . Natursch. Landscaping Brandenburg 17, supplement: p. 91