White-backed woodpecker
| White-backed woodpecker | ||||||||||||
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White-backed woodpecker ♂ ( Dendrocopos l. Leucotos ) |
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| Dendrocopos leucotos | ||||||||||||
| ( Bechstein , 1802) |
The white-backed woodpecker ( Dendrocopos leucotos ) is in Central Europe rare Buntspechtart . It is assigned to the subfamily of the real woodpeckers in the family of the woodpeckers (Picidae).
The 12 subspecies are mainly found in the southern mixed forest areas of the taiga from central Scandinavia eastwards to Kamchatka and Japan. Isolated occurrences exist in the Alpine region, in the Pyrenees and in Southeast Europe.
Appearance
The white-backed woodpecker is slightly larger than the generally known great spotted woodpecker ( D. major ), from which the species cannot always be reliably distinguished, especially when in flight. There is also a considerable possibility of confusion with the blood woodpecker ( D. syriacus ). The similarly colored middle woodpecker ( D. medius ) would have to be eliminated as a confused partner due to the differences in size.
The clearest distinguishing feature of the good blackbird-sized woodpecker is the purely black upper back, without any white shoulder stripes. The lower back is pure white in the upper part, hence the name of the woodpecker, more white-gray towards the tail. The wings are strongly banded in black and white. In the male, the crown is bright red up to the back of the head, in the female it is shiny black. Both sexes have a yellowish forehead over the base of the beak. The black beard stripe extends into the neck area, but is only fully connected to it in a few subspecies ( lilfordi ). The chest and belly are cream-colored with clear black vertical lines. The lower tail cover feathers are pink in both sexes. The subspecies lilfordi differs from the nominate form by a sub- beard stripe that extends to the nape of the neck and a black transverse banding on the white back.
voice
The woodpecker's contact call is a soft Kjük or Güg , much quieter, darker and more subdued than the great spotted woodpecker . When excited, these elements are lined up and then become quite bright and shrill shout lines. White-backed woodpeckers drum persistently and for a long time. The individual drum rolls last almost two seconds and consist of over 40 individual beats. While drumming the beat frequency increases and decreases again towards the end.
Voice example
- Contact call and drumming
- The language of the woodpeckers
distribution
The woodpecker's large distribution area is mainly in the Palearctic . In peripheral areas or isolated occurrences, the oriental and tropical fauna regions are also reached. The center of the closed distribution is in the southern taiga; it begins in central and southern Scandinavia and extends across all of Eastern Europe eastwards to the Pacific coast and Japan. In Europe, relic occurrences exist in the Pyrenees , the Alpine and Carpathian arches , in the southern Apennines and quite extensive in the Balkans . The species is also found in the Caucasus , in some areas of the Pontic Mountains and the Taurus . In East Asia, the occurrences extend to Taiwan and on the mainland to Sichuan and in the southeast to Fujian . The delimitation of the distribution of the subspecies is in part not fully clarified:
- D. l. leucotos : Its breeding area lies in the European habitats eastwards to about the Urals.
- D. l. lilfordi : Balkan Peninsula, Southeast Anatolia, South Apennines and Corsica . The white-backed woodpeckers of the Pyrenees are also usually assigned to this subspecies. This subspecies is considered by some authors as a separate species ( D. lilfordi ). Where lilfordi occurs sympathetically with leucotos , lilfordi populates the significantly higher-lying and more deciduous forest-dominated habitats.
- D. l. uralensis : The occurrence of this large, somewhat lighter subspecies adjoins those of the nominate form to the east and, following the southern border of the Taiga, extends as far as Lake Baikal .
- D. l. subcirris , the largest, thick- beaked and brightest subspecies, is common on the northern Japanese islands.
In southern East Asia this species is widespread in isolated regions, where the number of subspecies is correspondingly large. The white-backed woodpecker also penetrates the furthest south to the edge of the tropical region. These subspecies are smaller and darker in the basic color than the nominate form. The island race should be mentioned here
- D. l. owstoni , as it deviates most clearly from the basic color pattern. It occurs on some islands of the Ryūkyū Archipelago. The breed is small and short-billed, but has the largest wing length of all subspecies at 160 millimeters. The dirty white rump in the nominate form is black, the underside of the abdomen is broadly striped with black.
habitat
The ideal breeding habitats of the species are natural, mostly loosened forests with a high proportion of dying and dead trees, conditions that only exist in largely natural uncultivated forests. Deciduous and mixed deciduous forests are preferred to those with a high proportion of conifers, in East Asia the white-backed woodpecker populates almost exclusively pure deciduous forests. In the southern taiga forests, the highest stand densities were found in loosened birch and aspen stands along the large rivers. Often, comparatively high stand densities can also be found in forest areas affected by wind breaks or avalanches. Forest edge locations and border areas to more extensive clearings are preferred. Similar to the gray woodpecker, the species avoids pronounced cold islands and (at least in the northern part of the distribution area) sloping areas in northern directions. This thermophilic tendency is less attributable to the woodpecker itself than to some of its main sources of food (developmental stages of different species of beetles), which are more or less warmth-loving. In addition, lying dead wood in south-facing locations, on which this species primarily looks for food, becomes snow-free earlier in spring than in north-facing locations. Forests in their optimal growth phase are probably less likely to be populated than forest areas in their decay phase due to their relatively low light penetration and the lower proportion of dead wood. Forests in their youth phase are completely avoided by this species.
The vertical distribution of the species is diverse, so that no clear preference for a certain altitude level can be identified. The species inhabits suitable habitats from the planar level to the edge of the respective, geographically differently situated forest borders. The preference for submontane and montane habitats in Europe is related to the fact that only at these altitudes does the species meet its habitat requirements.
In Central Europe, the occurrence of the species is limited to a few exceptions (for example in the Murnauer Moos ) on alpine mountain locations.
behavior
The activity profile shows a two-peak course with activity peaks in the early morning and during the mid-afternoon. In between there are long periods of rest and cleaning. Similar to the great spotted woodpecker, the species is loyal all year round. However, it only shows territorial behavior during the breeding season. The phase of establishing or maintaining the territory usually begins in late winter with long rows of drums, which preferably take place on old trees that offer a clear all-round view. From this point on, male conspecifics are driven out of the area, they also show aggressive behavior towards the great spotted woodpecker.
On the ground and on large horizontal branches, the woodpecker moves by hopping on both legs, on steep branches by climbing, whereby the tail serves as a support as with most woodpeckers. The white-backed woodpecker does not climb upside down, but backwards. The woodpecker only climbs head first in the breeding cave.
The flight is a very fast arc flight, with strong wing flaps in the upward phase and the wings close to the body in the valley phase. Large, open areas are extremely reluctant to fly over.
The rest and cleaning periods during the day are usually spent hanging from a tree trunk, but the nocturnal sleeping periods in sleeping caves.
food
The white-backed woodpecker lives mainly on insects and their stages of development, especially those that occur in dying, dead or decaying wood. He shows a clear preference for the caterpillars of the willow borer ( Cossus cossus ) and the larvae of jewel beetles and various longhorn beetles . But it also reads freely occurring insects on trunks, branches or leaves. In summer and autumn, vegetable foods also play a certain role, especially bird cherries and hazelnuts . In East Asian subspecies, different nuts appear to play a larger proportion of the total diet.
Food acquisition
The white-backed woodpecker prey on its food animals by chopping up their feeding alleys in dead, often decaying wood. The resulting large and deep holes are characteristic of the species. Lying trunks are preferred, only when there is high snow cover standing trunks - mostly at low heights - are processed. During the breeding season, searching for leaves and twigs, and sometimes even hunting for flying insects, play a certain role.
Although the white-backed woodpecker tries to find its food only a short distance from the breeding cave, feeding flights of up to two kilometers are not uncommon. The areas of this type are correspondingly large.
Breeding biology
In terms of sexual and breeding behavior, the white-backed woodpecker shows some similarities with the great spotted woodpecker, but many areas of the breeding biology of this species have not yet been adequately researched and documented.
The white-backed woodpecker leads a monogamous breeding season, but there seems to be a certain loose connection during the winter months, so that re-breeding of last year's breeding parents is not uncommon. The pair formation and the establishment of the territory begin very differently in the region in late winter. During this time, the woodpecker is very noticeable because of its very loud drumming.
Pair formation
As with all woodpeckers, the courtship period lasts very long, apparently a very sensitive synchronization of behavior is necessary in order to enable an even reduction in aggression and thus a successful pairing. The first drumming can already be heard in the middle of winter, a little later chases (mostly in the vicinity of sleeping caves) can be observed. Then the male offers the female sleeping caves, but drives her away at the beginning of this courtship section; only when the female moves into a sleeping cave does the pairing appear to be complete.
Breeding cave
The breeding cave is usually built in dead deciduous trees that are often already infested with fungus. The spacious caves are up to 40 centimeters deep and about 15-18 centimeters wide. The loophole, which is often somewhat highly oval, is between 50 and 60 millimeters wide. The woodpeckers do not bring in any nesting material, and because of the soft material there are few chips on the cave floor. Usually several breeding caves are built, but it has also been observed that the woodpecker reused a breeding cave for years or that old sleeping caves were adapted as breeding caves. Brood losses due to the toppling of the often very weathered breeding trees are not uncommon.
Clutch and brood
The clutch consists of 3 to 5 pure white, more round oval eggs with an average size of 28 × 23 millimeters. So they are slightly larger than those of the great spotted woodpecker. Egg-laying begins as early as the beginning of April, but the periods of time show large regional differences. Both parents incubate the clutch for around 13 to 16 days. The nestling time is - depending on the weather - between 25 and 32 days. After the flight, the family group dissolves very quickly and the young woodpeckers leave the breeding area, whereby the migrations can lead to different distances and in different directions.
Hybridizations
Occasionally, especially at the edges of the distribution area, mixed breeds between great spotted woodpecker and white-backed woodpecker occur. Nothing is known about the fertility of the young with the plumage characteristics of both parents.
hikes
Adult white-backed woodpeckers are predominantly resident birds in their entire range. Young woodpeckers migrate , but they too usually do not move very far from the breeding area. Real migratory movements, which may be related to evasions of the great spotted woodpecker , which carry away individual white-backed woodpeckers , are rare .
Persistence and Threat
For large areas of the distribution area, there is no information on the population density and population dynamics. The well-recorded deposits in south-east Poland are stable, while in northern Poland the loss of habitat is having a serious impact. Across Europe, the species is considered to be secure ( S - secure ), although it appears in the Red Lists of most Central European countries. In the Red List of Germany's breeding birds from 2015, the species is listed in Category 2 as critically endangered.
This species of woodpecker has always been rather rare in Central Europe. In addition, the intensification of forestry has made many forest areas uninhabitable for the white-backed woodpecker. Nevertheless, more precise searches in recent years seem to suggest higher populations of the species than previously assumed. The white-backed woodpecker was first detected in Vorarlberg in 1975 ; afterwards a number of further areas could be determined. There are also good occurrences of this species in the Ötscher- Dürrenstein area in Lower Austria .
In Germany, the white-backed woodpecker is widespread in the Alps, in the Bavarian Prealps it occurs locally, sometimes largely isolated, for example in the Kürnacher Wald , the Buchenberger Wald and in the Pfaffenwinkel . In the Bavarian Forest , which is spatially separated from it , the species was widespread until the beginning of large-scale wood use. This population has been declining since then, only very small residual occurrences have been preserved.
In the short term, the species may also be able to benefit somewhat from the dying forests and the storm events of recent years.
In the long term, however, Central European stocks can only be secured by maintaining near-natural mixed forests with a large proportion of dead wood.
literature
- Hans-Günther Bauer / Peter Berthold: The breeding birds of Central Europe. Existence and endangerment. 2nd revised edition; AULA - Wiesbaden 1997. p. 293 f. ISBN 3-89104-613-8
- Urs N. Glutz von Blotzheim (Hrsg.): Handbook of the birds of Central Europe . Edited u. a. by Kurt M. Bauer and Urs N. Glutz von Blotzheim. Aula-Verlag, Wiesbaden. Volume 9. Columbiformes - Piciformes . 2nd, revised edition 1994, ISBN 3-89104-562-X , pp. 1079-1095.
- Georg Frank: The breeding season of the white-backed woodpecker Dendrocopos leucotos compared to the great spotted woodpecker Dendrocopos major in the montane mixed forests of the northern limestone Alps . In Vogelwelt 123 (2002) pp. 225–239; AULA-Wiebelsheim 2002.
- Gerald Gorman: Woodpeckers of Europe. A Study of the European Picidae. Bruce Coleman 2004. ISBN 1-872842-05-4 . Pp. 128-143
- Jochen Hölzinger (Ed.): The birds of Baden-Württemberg . Non-Singvögel Vol. 3 Eugen Ulmer-Stuttgart 1997. ISBN 3-8001-3908-1
- Amy C. Weibel, William S. Moore: Molecular Phylogeny of a Cosmopolitan Group of Woodpeckers (Genus Picoides) Based on COI and cyt b Mitochondrial Gene Sequences. In: Molecular Phylogenetics and Evolution , Vol. 22, No. 1, January, pp. 65–75, 2002. Article pdf engl.
- Hans Winkler , David Christie, David Nurney: Woodpeckers. A Guide to Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995, ISBN 0-395-72043-5 , pp. 258-260.
Web links
- Very good photos and excellent, scientifically sound text by Gerald Gorman
- Factsheet of Birdlife international 2005 (PDF file; 292 kB)
- Entry at the Swiss Ornithological Institute
- Dendrocopos leucotos in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2004. Retrieved on 9 January of 2009.
- Videos, photos and sound recordings of Dendrocopos leucotos in the Internet Bird Collection
- White-backed woodpecker feathers
Individual evidence
- ^ The language of the woodpeckers on spechte-online.de
- ↑ Gorman (2004) p. 131 f
- ↑ 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.
- ↑ Frank (2002)
- ↑ Wolfgang Scherzinger: The bird world of the primeval forest areas in the interior of the Bavarian Forest . In: Bavarian Forest National Park , issue 12, 1985, p. 127
- ↑ 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. 139
