Winter golden chicken
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Golden Grouse ( Regulus regulus ) |
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| Regulus regulus | ||||||||||||
| ( Linnaeus , 1758) |
The golden cockerel ( Regulus regulus ) is one of the smallest bird species in Europe . At around nine centimeters tall, it only weighs between four and seven grams. It is easy to confuse it with the golden cockerel , which, unlike the golden cockerel, has a white stripe over the eyes and bright yellow-green sides of the neck. The territories of these two species of birds, which have a variety of similar behaviors, occasionally overlap. However, the golden golden cockerel does not compete directly with the golden cockerel for food, as it has specialized in its food spectrum for the smallest prey and, unlike the golden cockerel, prefers to look for them on the underside of branches.
Golden Grouse breed predominantly in conifers. To build their nests, they use, among other things, textile material from the egg cocoons of spiders and the webs of some caterpillar species , thereby creating a particularly stable hanging nest. It is so well insulated that the female can leave the eggs to be incubated for up to 25 minutes in any weather without them cooling down.
Appearance
Winter golden chickens are on average about nine centimeters long. The body of the bird always looks fluffy, as the neck plumage is somewhat elongated and the head is not clearly raised from the body.
On the upper side of the body, the plumage is pale olive-green to yellow-green, while the underside of the body is gray-white to gray-green. The flight feathers are a bit browner compared to the rest of the plumage. The olive-brown arm and hand covers are lighter at the top and thus form a yellowish-white wing band.
Both sexes have a striking, color-contrasting stripe on the head, which is bordered on the sides by small black feathers. In females, the apex is pure yellow to yellow-green. In the male, however, the apex is orange in the center and yellow in the edge area. The orange feathers in the middle are mostly covered by the yellow edge feathers, so that the sexes can often not be distinguished when observing outdoors.
The plumage of the face is light and, unlike the golden cockerel, there is no dark line over the eye. The iris is dark and clearly set off by the surrounding light plumage. The beak is dark in color, the nostrils are covered by two bristle feathers.
Some body structure features indicate the high level of adaptation to life in coniferous forests. Similar to the coal tit , which also occurs in coniferous forest stands, the golden grouse also has a long and strongly curved back claw . There are pronounced callouses on the soles of the feet. In the golden cockerel, however, these are less developed.
As a rule, winter gold cocks avoid flying over larger uncovered areas. If they are forced to do so, their flight is reminiscent of the undulating of coal tits. At their destination, they land in the places where the branches are very close together.
voice
The singing and the calls of the winter golden chickens are so high that many people cannot hear them at all or only in the immediate vicinity. Tape recordings and sonagram analyzes are therefore essential tools for investigating the vocalizations of the golden cockerel.
Voice utterances such as voice feeler calls, warning calls and flight calls, which are not related to reproduction, are largely similar in winter gold cocks and summer gold cocks. This probably favors the swarming of the two species, which can occasionally be observed in winter. The distinctly different vocalizations when singing the territory prevent hybridization of the two species, whose territories sometimes overlap.
The territory song is only performed by the male; it can be heard particularly frequently from males who have just arrived in the breeding area and do not yet have a partner. Unlike many other bird species, the golden cockerel does not perform its territory song from an exposed vantage point. Rather, they let their singing sound while they are looking for food and interrupt them briefly when they have found a prey. How often it can be heard over the reproductive period varies from person to person. It can usually be heard for the last time when the young birds of the second annual brood fledge.
The Reviergesang consists of whispering elements that, in contrast to the golden cockerel, do not increase in pitch, but rhythmically increase and decrease in pitch. It ends with a short trill that is individually different. Often these Endschnörkel fremdimitierte contain elements such as the hüid of Zilpzalps or the pink of the book Fink . Neighbors and partners recognize each other by their final trills. Playing a final trill that does not come from a neighbor of the territory triggers a distinct, aggressive behavior in the males. On the other hand, the males hardly react to the final trill of a neighbor. The song is only partially innate in young birds; they learn the complete song from around the 10th day of life and have learned it by the time they fly out of the nest.
While the district song is only performed by males, the chattering song can be heard by both sexes. They let this chattering, soft subsong , in which they imitate many other species, be heard continuously. It is a melodious, very high performed, low "sisisis". In contrast to the Reviergesang it is completely innate.
distribution
Breeding area
The golden cockerel is a breeding bird in Europe, the Middle East, Southwest Siberia and the mountains of Central and Central Asia and also breeds in Japan. Its overall distribution is largely identical to that of the spruce ( Picea abies ). However, this bird species has some distribution gaps in this large range. For example, it is missing in large parts of Spain and in Eastern Europe.
Depending on the author, a distinction is made between 12 and 15 subspecies, with the species occurring in the east being somewhat larger. The nominate form Regulus regulus regulus is native to continental Europe. The subspecies R. r , which occurs in Great Britain and Ireland, differs from it . anglorum by a somewhat darker plumage. In the Azores come with R. r. azoricus , R. r. sanctamariae and R. r. inermis have three subspecies. The on Tenerife occurring Canary Goldhähnchen R. (r.) Teneriffae were previously allocated to the firecrest. Due to the behavior, the vocalizations as well as the district singing, this subspecies is now also assigned to the winter golden chickens, or viewed as an independent species.
The golden crown , which is widespread from North to Central America , used to be seen as a further subspecies of the winter golden cockerel . This is similar in behavior and appearance to the winter golden cockerel, but also shows similarity to the summer golden cockerel, especially in the head drawing. According to the current state of knowledge, it is to be regarded as an independent species.
hikes
Winter gold chickens are part pullers . Only the breeding populations of the far north completely leave their breeding areas in winter. Finland's breeding birds, for example, migrate south-west to Germany, Belgium, the Netherlands, Great Britain, and northern France. Occasionally they also reach the south of France, the north of Spain and Italy. While conspicuous mass infiltration in inland Central Europe is unknown, there is an occasional invasion-like occurrence in the Baltic and North Sea region. This is probably due to the high growth rates in Scandinavia, mild winters in Central Europe and favorable wind conditions. The migration from the breeding areas begins in August and lasts until November and the beginning of December, whereby the migration behavior is strongly dependent on the weather conditions. The homecoming starts in western Central Europe from the beginning to mid-March and usually lasts until May. So far, several daily train routes of 150 to 240 kilometers have been proven. The longest known train routes to date were 2,100 kilometers from St. Petersburg to Croatia and 2,475 kilometers from Bornholm to Algeria .
Density or diet-related evasions are not known for this species. Non-migratory populations have not yet been clearly identified; rather, the winter gold cockerel seems to be a migrant opportunist who, depending on the nutritional situation and weather conditions, shows a latent willingness to migrate until December.
habitat
The golden grouse is basically a coniferous forest dweller with a strong bond with spruce and other short-needle tree species. In the typical Central European distribution areas, golden grouse prefer to be found on not too dense, bushy old spruce trees with well-developed comb branches and / or lichen growth. In older hardwood stands, the golden grouse only breeds if there are spruce groups of at least sixteen to twenty trees. It also accepts spruce monocultures once the trees reach a certain minimum height. In the mountains, it also breeds in pure stone pine forests or in Swiss stone pine and larch forests .
Deviating from this, the golden grouse living in the Azores prefer to stay in the evergreen maquis and in the juniper bushes. The birds of this species found on Tenerife use tree heather as nesting trees.
Outside of the breeding season, golden grouse can also be seen in atypical habitats. They then also stay in pure deciduous forests or reed areas. During this time, they can also occasionally be seen in city parks with little coniferous wood.
food
Food spectrum
Goldfinches only eat small arthropods ; the amount of food they eat daily is at least equal to their body weight. In young birds, birds in the moulting phase or in females while they are laying eggs, the need for food can double.
The range of spider and insect species eaten is very large. However, golden-chested birds prefer the smallest and soft-skinned species possible. This also applies in comparison to the summer golden chicken. In studies of food choice, golden cockerels generally selected the smallest spiders from a spectrum of spiders of different sizes. Goldfinch, on the other hand, always preferred the largest spider in the same series of experiments. Springtails make up the largest proportion of their food in the winter golden cockerel . These small, bark-dwelling arthropods are also available in winter. The more food spectrum of Winter Gold cockerel includes spiders , small caterpillars, aphids , dust lice , psyllids , midges , lacewings , and insect and spin narrow Lege. However, there are a number of insects that fit into the prey scheme in terms of size and soft skin, but are still not eaten. These insects include butterflies from the groups of rams , blues and whites . Miniature spiders from the Erigonidae family are strangled back up by the golden chickens if they accidentally swallow them. Basically, female spiders are more likely to be accepted than male ones.
Freshly hatched young birds receive springtails as their first food, which are then supplemented by small caterpillars and spiders. As the young birds get older, their prey becomes larger. As Thaler-Kottek found, parent birds also feed prey that they would either not eat at all or only if there was a great shortage of food. From the 5th day of life of the nestlings, golden chickens also feed their offspring tiny snails, which are the prerequisite for bone formation. From the 12th day of life of the nestlings, the amount of snails fed decreases significantly.
Food acquisition
Unlike titmouse , the species of the golden cockerel are not able to grip their prey with their claws. They are also unable to break up their food with lateral beak movements, as is the case with grain eater. On the other hand, prey that are too big to be swallowed immediately because of wings or legs are thrown against a hard surface by them until all bulky extremities have been removed.
90% of their daily activities are spent foraging for food. As a rule, they look for their food along branches and stay on the underside of the branches more often than summer golden-chickens. Preferred foraging places are the comb branches of older spruce trees. As a rule, golden cocks do not look for food on the ground, and they usually cover their water needs with rain and dew drops from the tips of branches. However, when foraging for food, golden grouse occasionally seek out scrub near the ground. In heavy snowfall, they occasionally even slip under the snow cover in order to get to the spruce branches below. There they can still find enough springtails and other small insects of their prey spectrum to survive under these weather conditions. During the foraging for food, a wing twitch is characteristic of the winter goldchick, during which the wing opposite to the direction of movement is usually stretched laterally upwards. Excited birds also twitch both wings.
Winter golden chickens are limited to prey animals that are immediately recognizable to them. In contrast to titmice, for example , they do not look for prey that are hiding. For a meter of branch length you spend about 1 minute. Your mode of movement changes very quickly and immediately. Sometimes the birds flutter and hop along the branches; Again and again they examine the underside of the branch by clinging to a vertically hanging branch, or they climb down hanging branches hanging head down. Occasionally they go into a hovering flight , for example to pick off insects from one end of a branch. In this way, they are also able to pick insects out of a spider's free-hanging web of webs. In a short dive, they occasionally prey on rapidly abseiling spiders or flying insects. The latter, however, are not followed over a longer distance.
Often the birds do not allow themselves to be disturbed by people in close proximity while they are looking for food.
Comfort behavior
The golden cockerel brushes its plumage several times during the day. This cleaning phase can only last up to 15 minutes during the moult. Maintenance phases of just two to three minutes are typical. In winter, on the other hand, the cleaning sequences are limited to just a few seconds, but are then carried out several times per hour. The birds use rain to bathe between the wet branches. In winter, freshly fallen snow on the branches can be used for intensive bathing phases.
Dense spruce branches are the preferred roosting place for winter golden chickens. You look for the places on the top of a branch that is particularly well protected by branches hanging over it. In winter in particular, several winter golden chickens gather at such places and occasionally even maintain physical contact with one another.
Reproduction
Imposing behavior and agitation
Goldfinches are territorial birds. The behavioral repertoire of both genders therefore includes an impressive behavior that plays a role both in defending the territory and in choosing a partner. Impressive birds fluff themselves up, the crown feathers are slightly spread apart and the tail occasionally fanned out a little. This imposing attitude is shown, for example, when males recite their territorial song. In direct confrontation with conspecifics this attitude of imposing increases. The crown feathers are then raised to the maximum, the wings spread slightly and the bird kinks with its beak lowered towards its conspecifics. In females, this demonstration behavior can be observed especially in autumn, when up to five females impress each other. An intensely performed buzz can be heard. In a confrontation between two males, this demonstration behavior can very quickly turn into a direct attack. The two claw each other, fall to the ground with violent wings flapping and try to teach each other beak blows.
The male willing to mate also shows intense impressing towards females. It initiates the so-called Hetzkopulae, in which the female escapes the attempts of mating by the males by fleeing. These Hetzkopulae are an integral part of the mating behavior in winter gold-chickens and probably serve to synchronize the two partner birds. It is also regularly triggered by the female, for example by demonstratively entering nesting material in front of a male who initially ignores her or by flying close to him. Females willing to mate remain motionless on a branch with slightly spread wings and have occasionally spread their cloaca feathers.
Only the male, on the other hand, shows sightseeing flights in which it flies around isolated spruce trees in tight spiral flights. Trees that are on the border to the district neighbors are preferred for display.
Breeding area and nest
The breeding grounds are small with a surface area of less than 50 by 50 meters, the shape of the area is determined by the topography and the vegetation of the area. From field observations it is known that even 18 to 19 large trees are enough to provide a pair of golden chickens including their offspring with sufficient food.
Males occupy a territory and then chase after the females, who appear lured by the territory chants in the territory. These rushing flights then gradually turn into a nesting display by the male. The male indicates nesting sites to the female by shouting and slowly turning around the body axis as well as vibrating wings. Comb branches are preferred as nesting places, the drooping branches of which allow the nesting nest that is typical of golden chickens to be built. If the female shows no interest in the location suggested by the male, he will concentrate on other places in his territory with his demonstrative nesting point. If the female shows interest in a location, the male starts building the nest. The hanging nest is built in the tight tangle of branches of conifers. Spruce trees are the preferred nesting tree.
Winter goldchickens usually have two broods per year. The nest building of the first nest is initiated by the male. The female also participates from about the third day; Overall, the birds spend around 20 days building nests. The outside of the nest consists mainly of mosses and lichens as well as textile materials from the egg cocoons of spiders and some species of caterpillars. The nest is held in place by the drooping branches that are firmly intertwined into the outer wall. The use of lichen in the outer wall is typical of winter golden chicken nests. Goldfinches tend to use moss for this. The middle layer consists of loose moss and lichen. Feathers and hair from various animal species make up the inner lining. The second nest building is initiated by the female. It usually goes faster than the first.
The nests are very stable and so well insulated that females can leave their clutch or the young birds for a long time. Abandoned nests can withstand the weather for years.
The clutch
Shortly before they lay eggs, the females of the golden cockerels start asking the males to mate. The nest building is then so advanced that the parent birds are in the process of padding the nest inside. The laying of eggs for the first clutch depends on the geographical location and can begin as early as March. However, it typically takes place in April. The second clutch will be laid from around June. It is a box brood , the female lays the eggs of the second clutch before the young of the first have fledged. During this time they are cared for by the male. The clutch size is very large; it contains on average between eight and 11 eggs. A single egg weighs less than a gram. The basic color of the eggs is white, they have a brownish-yellow markings that condense at the blunt pole of the egg.
The clutch is only incubated by the female. The females only stay briefly on the nests, after 20 minutes at the latest they search for food and return to the nest after about 10 minutes. Since only a few eggs are in direct contact with the brood spot because of the large clutch, the female turns the clutch over at short intervals with kicking movements of her legs.
Regulus regulus regulus
Regulus regulus azoricus
Regulus regulus inermis
Regulus regulus teneriffae
The young birds
Young birds hatch about 15-16 days after the start of breeding. Most of the young birds in a clutch have hatched after about two days. The eggshells are immediately carried out of the nest by the parent birds and placed far away from the nest. The boys' droppings are initially swallowed by the parent birds. The feces of nestlings who have already reached the 5th day of life, on the other hand, are transported away by the parent birds and deposited far away from the nest.
The young birds of the first clutch are mainly fed by the male. For the first few days, the female huddles intensely, but then gradually begins to build the second nest. Only with the young birds of the second clutch does the female also participate to the same extent in feeding the offspring. The spherical shape of the hanging nest means that from the third day of life the nestlings lie on top of each other in the nest. Young birds lying on top that have just been fed have a tendency to move into the interior of the nest, i. H. to crawl under their nest siblings. This behavior encourages all the young birds in the nest to be fed by their parents.
Age
Winter golden chickens can live to be 4 years old. However, they are particularly at risk during late autumn and winter. During this time, many golden chickens die of lack of food or cold. It is particularly critical for them when a layer of ice forms on the branches and so they have no way of looking for springtails as usual along the branches. Golden Grouse have been observed several times as they slip into snowdrifts along spruce trees. They then look for food along the snowed-in spruce branches.
Inventory and inventory development
The total European population is estimated at 19 to 35 million breeding pairs at the beginning of the 21st century. Countries with populations of more than one million breeding pairs include the European part of Russia (8 to 15 million breeding pairs), Sweden (two to four million breeding pairs), Romania (1.84 to 2.45 million breeding pairs) and Germany (about one Million breeding pairs). In Central Europe a total of about 2.3 to 4.3 million pairs breed.
Winter gold chickens are subject to considerable fluctuations in the population. The reasons are the high losses during the train and very hard winters. In the lowlands of Central Europe, the golden cockerel is a relatively new breeding bird. Larger stands probably only developed in the course of the 19th century, when large areas of spruce were planted in these regions. This also promoted the spread and increase in the low mountain ranges. Wherever there is significant pollution damage in forests, stocks have in some cases significantly decreased. This applies, for example, to the Ore Mountains, the Giant Mountains and the Bohemian Forest. The reason for this is that the thinned branches no longer offer sufficient protection for the golden cockerel and the food supply is severely impaired.
supporting documents
literature
- Hans-Günther Bauer, Einhard Bezzel and Wolfgang Fiedler (eds.): The compendium of birds in Central Europe: Everything about biology, endangerment and protection. Volume 2: Passeriformes - passerine birds. Aula-Verlag Wiebelsheim, Wiesbaden 2005, ISBN 3-89104-648-0 .
- Einhard Bezzel: birds. BLV Verlagsgesellschaft, Munich 1996, ISBN 3-405-14736-0 .
- Urs N. Glutz von Blotzheim (Hrsg.): Handbook of the birds of Central Europe . Vol. 12/2 Passeriformes (3rd part) Sylviidae, 3rd edition, Aula-Verlag, Wiesbaden 1991, ISBN 3-89104-511-5
- Ellen Thaler-Kottek: The golden chicken. Westarp Sciences, 1990, ISBN 978-3-89432-367-7 .
Web links
- Regulus regulus in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2004. Retrieved on January 4 of 2009.
- Videos, photos and sound recordings of Regulus regulus in the Internet Bird Collection
- Information about the winter golden cockerel and bird's voice at www.vogelwarte.ch
- Sonatura audioblog singing and sonagrams about the golden cockerel
- more pictures and information at www.natur-in-nrw.de
- Age and gender determination (PDF; 2.6 MB) by Javier Blasco-Zumeta and Gerd-Michael Heinze (English)
- Golden Cockerel feathers
Footnotes
- ↑ a b Bezzel, Vögel, p. 439
- ↑ Bezzel, Vögel, p. 329
- ↑ a b Hans-Heiner Bergmann; Hans-Wolfgang Helb; Sabine Baumann; The voices of the birds of Europe - 474 bird portraits with 914 calls and chants on 2,200 sonograms , Aula-Verlag, Wiesbaden 2008, ISBN 978-3-89104-710-1 ; P. 474
- ↑ For a detailed description of the song of the golden cockerel and the illustration in sonograms see Thaler-Kottekt pp. 37–53
- ↑ The different subspecies depending on the author is described in more detail in Thaler-Kottek, p. 14f
- ↑ a b c d e f Bauer et al., P. 288
- ↑ a b c Bauer et al., P. 289
- ↑ a b For a detailed description of the food spectrum see Thaler-Kottek, pp. 23–37, and pp. 115–119. Among other things, she has carried out extensive studies on the food preferences of the golden cockerel in aviary birds
- ↑ a b For a detailed description of the food spectrum and food acquisition see Thaler-Kottek, pp. 21–37. Among other things, the author has carried out extensive investigations into aviary birds on the nutritional preferences of the golden cockerel
- ↑ Thaler-Kottek, p. 53f
- ^ Encyclopedia of the European Bird World (Birds of Britain and Europe 1997), translated by Angelika Lang, Tosa Verlag 2003, p. 209, ISBN 3-85492-813-0
- ↑ Thaler-Kottek, p. 54
- ↑ Thaler-Kottek, p. 61
- ↑ Thaler-Kottek, pp. 118f
- ↑ Thaler-Kottek, p. 102ff