Dipper
| Dipper | ||||||||||||
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Dipper ( Cinclus cinclus gularis ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Cinclus cinclus | ||||||||||||
| ( Linnaeus , 1758) |
The dippers or Eurasian dipper ( Cinclus cinclus ) is the only occurring in Central Europe representative of the family of dippers (Cinclidae). The roughly starling-sized , rounded-looking songbird is closely tied to life along fast-flowing, clear waters. There the species feeds mainly on aquatic insects, which it prey mainly on diving.
The species builds extensive spherical nests in half caves or natural caves along their feeding waters, in bank barriers and under bridges and other structures accompanying the river. It is a resident bird and only leaves the breeding waters when they freeze over.
The dipper is distributed with 13 subspecies from Western Europe and Northwest Africa eastward to the region around Lake Baikal and the highlands of Western China.
After heavy losses in the second half of the 20th century, the populations of most of the subspecies have largely recovered. According to the IUCN, the species is not endangered.
Appearance ( Cinclus c. Aquaticus )
At around 18 centimeters in length, the dipper is slightly smaller than a starling . The rounded, short-tailed bird is unmistakable in its habitat. The head and neck are medium brown without drawing, the rest of the upper side is slate gray; the dark brown color of the feather hems gives the impression of scaling. The throat, neck and chest are usually pure white, sometimes slightly creamy in color. Towards the belly, this bib is bordered by a rust-brown, more rarely also an orange-brown stripe; The lower abdomen, rump and the underside of the control feathers are dark gray-brown. The bill is blackish, as are the strong feet and toes. The long claws are strikingly bright, almost white. The iris is dark brown. The sexes do not differ in appearance; Males are a bit heavier on average over the year and have slightly longer wings.
Fledglings are slate-colored on the upper side and flaky white-gray on the underside. Her legs are light gray with a hint of pink. In October of the year of birth at the latest, the young birds molt into the adult dress.
Mauser
The moulting of the dipper proceeds according to the usual songbird pattern, but differs from it in the special length of more than 80 days and the course in three clearly separated phases: First the inner five hand wings fall, then the outer ones and finally the arm wings . The moulting of the control springs runs from the center outwards. While the dipper is fully airworthy during the moult, its maneuverability is severely limited. But since there are always two wing parts, it is not too hindered in the search for food. During the moult, the birds behave very hidden and usually stay in a small, particularly prey-rich section of their territory.
Vocalizations
The dipper has a rich vocal repertoire, but their calls and chants are often drowned out by the loud background noise of their living space. This is why the noticeable kinking, perhaps also the constant blinking of the eyes, is of communicative importance. The singing is a 20 second sequence of chirping and trilling phrases in different pitches, in which pressed, gossiping and scratchy sounds as well as soft whistling tones are embedded. Very often the singing begins with a conspicuous, sharply accentuated, ascending and descending (often six-syllable) input element. Most often - and best in late winter due to the low water level - the singing can be heard in the pre-breeding season in February and March; but both sexes sing with different intensity throughout the year. In addition to this singing, diverse calls depending on the situation and mood can be heard; some sound like zit , zrib or zrik ; in the clearly audible, purring flight she often calls zip… zip… zip… , sometimes individually zerb or zirrb .
Habitat and Distribution
The brood distribution of the dipper is closely tied to clear, current and oxygen-rich rivers; It shares large parts of its range with the gray wagtail . In some regions it is a very rare breeding bird, but with favorable living conditions it can reach very high population densities. The preferred habitats are streams and rivers in the trout region ; mostly, but not exclusively, these bodies of water are wider than two meters and have a minimum flow rate of about one cubic meter per second at a flow rate of 12-20 centimeters per second. It only penetrates the grayling and barbel region occasionally . The waters must have a stony or gravelly subsoil and, at least in sections, densely bushed banks. Small waterfalls, rocks or large stones in the watercourse as well as bank breaks are cheap props. It is important that the water flow is as even as possible and that there is no ice in winter. Sections of watercourse without dense vegetation and rivers in dense forests are not populated. The water quality of the breeding waters is usually very high, but dippers hold on to a selected stretch of water for a long time even if the quality deteriorates significantly. The dipper seldom appears as a breeding bird in slowly flowing streams, lakes or canals; it is more often to be found in such biotopes in winter . If the conditions are favorable, dippers can breed in settlements or industrial areas.
The settlement density depends on the food supply and the supply of favorable nesting opportunities; it varies from a few 100 water meters to a few water kilometers per breeding pair. A couple will need about 1 acre of shallow water. Good dipper areas have about one breeding pair per kilometer of water. The minimum nest spacing is less than 100 meters; Bigyny could play a role with such close nest spacings . The dipper is represented vertically from the lowlands to heights of over 4000 meters. Especially C. c. cashmeriensis and C. c. przewalski are pronounced high mountain birds, but also the Central European subspecies C. c. aquaticus soars to great heights. There are breeding season observations from Switzerland from an altitude of over 2500 meters.
The dipper is a breeding bird of the western and central Palearctic. In the east, their range overlaps widely with that of the river dipper ( Cinclus pallasii ); in these areas C. pallasii often inhabits slower flowing and wider waters than C. cinclus .
The species occurs from the British Isles , eastern and central France, parts of Spain, Portugal, Morocco and Algeria over large parts of Central Europe and Scandinavia, Italy, eastwards over the Urals to the Baikal area. An isolated distribution island is said to exist in the Stanowoj Mountains . In the Balkan countries the species breeds in different densities, in the low mountain ranges and mountain areas of Romania the most individual breeding occurrences of the dipper are found in Europe. In the southeast the Pontic area of Turkey , the Taurus , the Caucasus and adjacent areas, the Elbursgebirge and parts of the northern Khorasan are populated. The species is widespread further east in the mountains of Afghanistan and Pakistan as far as the Mongolian Altai . In the southeast the dipper breeds in the Pamir and Hindu Kush mountain ranges and further east in the Altun Shan and Nan Shan on the south side of the Tarim Basin . The most south-eastern occurrences are on the northern flank of the Himalayas .
hikes
Most populations of the dipper are resident birds that stay in the breeding area even in harsh winters; only when the food waters freeze over are they forced to migrate, mostly downstream. Females seem to be more willing to move than males. Scandinavian, North Russian and Caucasian dippers regularly leave their breeding area and migrate in southern and southeastern directions to central and southern Finland, the Baltic States and Poland, or in the southern Urals, as well as in the deep river valleys of the southern Transcaucasus, and occasionally further into the North iraq . Nothing is known about possible migration strategies of the African and Central Asian populations.
The youth dispersion is generally small-scale; Young birds try to establish their own territory within a few kilometers from the place of birth. Settlements 50 kilometers away and more have been found, but are exceptions. Since dippers mostly follow the watercourses on the diversified hikes and watersheds play a certain role, the actual flight kilometers traveled can be quite considerable, even if the distance as a straight line is short.
Food and subsistence
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Dippers only feed on animals; Vegetables that were found in nutritional analyzes are components that were taken in by chance; The stones that are often found in the stomach are mostly swallowed together with the shells of the caddis fly larvae, but are occasionally also specifically ingested.
Among the prey typical of fast-flowing waters of insect species, especially the predominant larvae of caddis flies , mayflies , stoneflies , blephariceridae and blackflies . The larvae and sex animals of gnats and those of various water beetles are less important . In other invertebrates, freshwater snails , worms , amphipods and water lice play a certain role. Occasionally small fish, especially bullheads , fish spawn and, more rarely, tadpoles are consumed. Terrestrial animals such as beetles, ants, millipedes and spiders are also captured on occasion. Indigestible food residues are choked up as bulges. At the beginning the nestling food consists almost exclusively of the larvae of mayflies; later larvae of caddis flies predominate.
Dippers use different strategies to acquire food. The simplest form is to pick prey from the ground, from the surface of the water or from leaves; occasionally stones are turned over or leaves are turned. When water-peeping , dippers dip their heads into the water from a standing or swimming position and thus search the surface near the ground for prey. The most common and specialized method of obtaining food is diving. Under water, dippers turn stones and loosen stuck insect larvae from the substrate by turning their heads. Rarely, and only when there is a particularly abundant supply, does the species hunt for flying insects in the air.
behavior
The dipper's activity period begins shortly before sunrise and ends around sunset. The early morning and late afternoon are used most intensively for foraging. In between there is an extensive break around noon, used for rest and plumage care. Even during the intensive foraging for food, breaks are taken to rest and care for plumage. She spends the night in sheltered places, often in niches, semi-caves or caves, mostly on the edge of the water in her territory, but usually not in a nest.
Move
On land the dipper moves around, tripping, running or hopping. She is able to cling to structured, almost vertical surfaces and to move there, sometimes hopping upside down. It flies open to cover longer distances. In a quick, whirring flight, it usually follows the course of the water at a low altitude, rises at the boundaries of the territory and returns in a curve to its territory. Occasionally, especially before diving in from flight or when hunting for insects in the air, dippers shake like flycatchers . Cross-country flights take place at a speed of around 50 km / h at altitudes between 50 and 100 meters. In doing so, it also crosses wider stretches of sea, for example the Baltic Sea.
Dippers are one of the few songbirds that swim and dive. When swimming she rows her legs; when diving, the body is inclined downwards against the direction of flow, the tail is erect; this pushes the bird's body against the bottom of the water and the bird can linger there, saving energy, and looking for food. The immersion can be done from flight, by falling from a control room or from swimming; underwater the dipper paddles with its feet and pushes itself off the ground with them. The main propulsion effect, however, is caused by the rudder force of the wings. The arm swings are largely applied, while the rowing work is carried out by the flexible hand swings. The average dive times are between 5 and 10 seconds. In exceptional cases, the dipper can dive for up to 30 seconds.
Particularly noticeable, almost characteristic movements of this type are the kinking and the blinking . When buckling, the bird briefly kinks in the heel joint; the rest of the body is kept level and still. The wings are often spread slightly; Often there is a slight turn of the body after each kink. The intensity of the kink depends on the excitement. Up to 81 individual elements per minute were counted. The kink is probably mainly of communicative importance. A supporting function in spatial vision is also discussed.
The blinking caused by reflexive closing of the eyelids is not more common in the dipper than in other songbirds, but is more noticeable due to the otherwise hidden white border of the upper eyelid. It has nothing to do with the movements of the nictitating membrane that it was previously associated with.
Breeding biology
Young birds try to found a territory in their first autumn and winter; they become sexually mature in the first late winter. Due to the mostly unequal gender distribution (more males hatch in most populations), annual males often do not breed. Dippers lead a largely monogamous seasonal marriage; Bigyny as well as partner change between first and second brood have been proven and should not be uncommon. The great loyalty to the breeding site of both partners often leads to multi-year mating, and occasionally to lifelong partnerships. In most populations there are regularly two, in exceptional cases three broods.
Courtship and pairing
Pair formation begins in autumn and reaches its peak in late winter. During mating, the male umtänzelt umschwimmt or singing and with deep lashing shouts of the female; it twitches its wings, kinks constantly and presents its white breast. If the female flies up, it is often followed up over the treetops; Impressive imposing flights followed by imposing diving , in which the male falls into the water with a clap, are part of the courtship ritual. Little by little, the female also becomes active, dancing around the male with kinks and trembling wings; Occasionally the partners stand face to face in this pose, chest to chest, with trembling, hanging, often raised wings, or jump at each other singing. When the female accepts food offered by the male, pair formation is complete.
Nest location and nest
Suitable nesting sites are usually rare in the breeding habitats of the dipper. For this reason, once a nest location has been chosen, it is often persistently retained even after broods have been lost; old nests are usually only repaired and rarely completely renewed. The male has the initiative in choosing a nest by flying to a certain place, singing there and simulating a nesting trough with rotating movements. The nest locations are consistently directly on the water, often only a few centimeters above the waterline; they are therefore occasionally at risk of flooding. Nesting sites are often half caves or niches in the bank area, for example in bank barriers, on the ledges of bridges or buildings, under roots that have been flooded free or in bank breaks. Usually the nest is covered from above against rain, semi-dark areas are preferred. Sometimes the nest is completely built into a cave and can hardly be seen from the outside. Occasionally it is behind a small waterfall. Nesting aids are often accepted by the dipper.
The nest will be built by both partners in around 14 days if the construction process is undisturbed. Construction usually begins at the end of February. The nest itself is a voluminous, spherical construct, which consists of an outer nest made up primarily of tightly interwoven moss, the bowl made of grass panicles and the nest hollow lined with leaves. The nesting material is installed wet and often dipped into the water before use. A characteristic of dipper nests is the downward-hanging beard under the entry hole, which serves both as a rain eaves and as a stopping point when the feeding parents no longer slip into the nest. The spherical design, closed at the top, is also retained in half-caves and caves. The entrance hole is on the side and at 70 millimeters × 50 millimeters is usually wider than it is high. Newly built nests have a diameter of about 20 centimeters. However, since they are reused for years and are constantly being expanded and expanded, they can grow into extensive structures of over half a meter in diameter.
Clutch and brood
In Central Europe the laying period begins in mid-February and ends in mid-June. Late broods were found in July. At higher altitudes and in the northern distribution areas, the start of breeding shifts to April and May; Breeding data from Southeast Europe and Asia are not available. As with other bird species, there has been a significant advancement of the average onset of breeding in the last 20 years, a phenomenon that is to some extent related to global warming, but more strongly to the increasing anthropogenic use of rivers, which often leads to their warming . The beginning of breeding of the dipper in Central Europe correlates significantly with the full bloom of the coltsfoot and the wood anemone .
A full clutch consists of four to six pure white pointed oval eggs with a size of about 26.6 millimeters × 18.8 millimeters. Second broods occur regularly. In these, the clutches are usually somewhat smaller, and the average size of the eggs is also somewhat smaller. The eggs are only incubated by the female, usually from the penultimate egg, for an average of 16 days; during the breeding season, the male stays near the nest and occasionally feeds the female, who, however, also leaves the nest and looks for food. In the first few days, the chicks are hoofed by the female and fed by the male; later both parents feed and remove the dung balls. After about 24 days the young leave the nest. They will be looked after by their parents for another ten to 14 days before they emigrate. Second broods start on average nine days after the first brood has fledged, sometimes even earlier. In such cases, the male alone takes over the leadership of the young birds of the first brood, while the female is already sitting on the second clutch.
The success of the excursion was determined in a large study in Baden-Württemberg with 67.9%. Of 902 clutches with 4076 eggs, 2769 young flew out.
Systematics
The dipper is one of the five species in the genus Cinclus within the family Cinclidae; Occasionally this is also understood as a subfamily (Cinclinae) of the flycatcher (Muscicapidae). Two species are in Eurasia, one is in North America and two are native to South America. The relationship of the family is the subject of research. In the past, they were placed close to wrens due to their morphological and behavioral similarities ; today, a closer relationship with the thrushes (Turdidae) and mockingbirds (Mimidae) is assumed to be more likely.
Over 20 subspecies have been described, 13 of which are generally recognized today. Two groups of subspecies can be distinguished: the cinclus group in Europe, North Africa and the Middle East, and the leucogaster group in Central and East Asia, in the Himalayas and in western China. Different color morphs occur in birds of the leucogaster group, otherwise the subspecies are only weakly differentiated. There are major differences in the color of the belly border of the breast flap, in the color of the belly itself and in size. However, phylogenetic studies of the European subspecies did not show any agreement with their morphological differentiation, so that the validity of these subspecies appears questionable overall.
- C. c. cinclus ( Linnaeus , 1758) : The nominate form occurs in Scandinavia, the Baltic States and northwestern Russia. In the south, usually separated by a non-occurrence zone of different widths, the range of C. c. aquaticus . Birds of the nominate form have no or only slight reddish-brown coloring elements in the chest area. The dipper from Spain and Corsica and probably also from Sardinia are occasionally described as separate subspecies ( C. c. Pyrenaicus or C. c. Sapsworthi ), but mostly either of the nominate form or the Central European subspecies C. c. aquaticus .
- C. c. gularis ( Latham , 1802) : The British dipper is a breeding bird in the eastern part of Scotland, on the Orkney , in Wales and in western England . The subspecies is relatively light on the upper side, the white breast flap is smaller than in C. c. aquaticus and the chest band rather maroon; The belly and flanks are gray.
- C. c. hibernicus Hartert, E , 1910 : The Irish dipper is common in Ireland, western Scotland and the Hebrides . It largely resembles C. c. gularis , but is darker in the flank and abdominal area.
- C. c. aquaticus ( Bechstein , 1796) : This subspecies occurs from eastern Spain, eastern France and Belgium across all of Central Europe eastwards to Poland and southwards to Sicily and Greece. By C. c. aquaticus , the only weakly differentiated color variants C. c. rufipectoralis and C. c. orientalis severed.
- C. c. minor Tristram , 1870 is native to the mountainous areas of North Africa. It is (irrespective of the name) somewhat larger, but above all significantly more long-billed than C. c. aquaticus , which is otherwise largely similar in color.
- C. c. caucasicus Madarász , 1903 : This subspecies, which occurs from eastern Turkey and the Caucasus countries eastwards to northern Iran, is strikingly dark. The belly side can be almost black, there is a reddish-brown color shimmer in the chest area, but an actual chest band is missing. The dippers that have not been found in Cyprus since 1958 were very similar to this subspecies; they were named C. c. olympicus .
- C. c. persicus Witherby , 1906 : Only occurs in a small area in southern Zagros. Very similar to C. c. caucasicus , but larger and less contrasting, paler in color.
- C. c. rufiventris Tristram , 1884 : This small subspecies occurs in the Lebanon Mountains. It is a little darker than C. c. persicus .
- C. c. uralensis Serebrovski , 1927 : subspecies that breeds on rivers and streams in the Ural Mountains . This subspecies is very similar to the nominate form, but the back color is slightly paler and brown. A narrow brown bib can be seen in most individuals.
- C. c. leucogaster Bonaparte , 1850 : This subspecies inhabits the largest area of distribution. It extends from northern Afghanistan north-east to the Baikal region, possibly to the western flank of the Stanowoj Mountains. Three color morphs are described: a completely white-bellied, one black-brown on the entire underside and an intermediate colored with a black-brown belly and white throat and chest area.
- C. c. cashmeriensis Gould , 1861 : A subspecies that occurs mainly in the western Himalayas and the adjacent mountain ranges. It largely resembles the high mountain birds of the Caucasus.
- C. c. przewalski Bianchi , 1905 : Occurs east of cashmeriensis in southeastern Tibet , Bhutan and western China. Very similar to the nominate form, like this without reddish-brown coloring, but darker on the back and abdominal plumage. In western China there are uniformly black-brown colored birds.
Stock situation, causes of danger and life expectancy
The population of the dipper is apparently not endangered in its entire range and seems to be stable at a high level. However, hardly any reliable studies are available from the North African and Asian breeding areas.
The high populations of the dipper in large parts of Europe declined rapidly in the early 1960s; This was due to bank construction, river straightening and other hydraulic engineering measures; In addition, water pollution and the abandonment of many small mills and other water-supported small craft and industrial companies had a negative effect on the density of the species. Since the mid-1980s, extensive water remediation , regulatory demolitions, but also the installation of nesting aids stopped the decline. The populations were able to recover, so that today most of the suitable dipper habitats are occupied in large parts of Europe.
The most important natural causes of loss are floods during the breeding season, predators such as birds of prey , martens and water vole as well as very harsh winters that freeze over large areas of the food waters. More serious, however, are still anthropogenic interventions in the habitats of the species. Above all, ever increasing leisure activities have a negative effect on the population of the dipper.
Little information is available on the life expectancy of the dipper. In general, the mortality rate of young birds is likely to be very high; in larger studies, an average life expectancy of around two years was calculated. Rediscovery of nest-young ringed birds once resulted in 8.5 years for C. c. aquaticus and 5.75 years for C. c. cinclus . A six-year-old female brooded at least 7 times and brought 30 young to fly.
literature
- Hans-Günther Bauer and Peter Berthold : The breeding birds of Central Europe. Existence and endangerment. 2nd Edition. AULA-Verlag, Wiesbaden 1997, ISBN 3-89104-613-8 , pp. 322-323.
- Einhard Bezzel, Roland Prinzinger: Ornithology. Ulmer, Stuttgart 1990. 3-8001-2597-1.
- Urs N. Glutz von Blotzheim (Hrsg.): Handbook of the birds of Central Europe . Edited by Kurt M. Bauer and Urs N. Glutz von Blotzheim, among others. 17 volumes in 23 parts, academ. Verlagsges., Frankfurt / M. 1966ff., Aula-Verlag, Wiesbaden 1985ff. (2nd ed.). Vol. 10, Part 2; ISBN 3-89104-435-6 , pp. 958-1020. = HBV .
- David Brewer, Barry Kent MacKay: Wrens, Dippers and Thrashers. Yale University Press, New Haven / London 2001, ISBN 0-300-09059-5 , pp. 19, 62-63 and 199-202.
- Gerhard Creutz: The dipper. (= Die Neue Brehm-Bücherei. Volume 364). A. Ziemsen Verlag, Wittenberg Lutherstadt 1986, ISBN 3-7403-0008-6 .
- Johann Hegelbach: Water temperature and flower phenology as an indicator of the earlier start of breeding of the dipper (Cinclus cinclus) in the Swiss plateau. In: Journal of Ornithology Volume 142, 2001, pp. 284-294.
- Jochen Hölzinger (Ed.): The birds of Baden-Württemberg. Volume 3: Singvögel 1. Ulmer, Stuttgart 1999, ISBN 3-8001-3493-4 , pp. 244-264.
- Béatrice Lauga, Christine Cagnon, Frank D'Amico, Solange Karama, Claude Mouchès: Phylogeography of the White-throated Dipper (Cinclus cinclus) in Europe. In: Journal of Ornithology. 146, 2004, pp. 257-262.
Web links
- Summary, illustrations and singing example from RSPB.org
- Videos, photos and sound recordings for Cinclus cinclus in the Internet Bird Collection
- Cinclus cinclus inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved September 8, 2013.
- Data sheet Birdlife Europe (PDF file; 277 kB)
- Data sheet Birdlife International
- Entry at the Swiss Ornithological Institute
- Age and gender characteristics (PDF; 1.7 MB) by Javier Blasco-Zumeta and Gerd-Michael Heinze (English)
- Feathers of the dipper
Individual evidence
- ↑ J. Hegelbach (Zurich / Switzerland): The moulting of the dipper - modified the songbird scheme. In: J. Ornithol. 143, p. 230 (2002)
- ↑ HBV (1985), Vol. 10/2, p. 1012.
- ↑ Creutz (1986), p. 97.
- ↑ Creutz (1986), p. 53.
- ↑ HBV (1985), Vol. 10/2, p. 987
- ↑ a b HBV (1985), Vol. 10/2, p. 988.
- ↑ a b Creutz (1986), p. 19.
- ↑ HBV (1985), Vol. 10/2, p. 975.
- ↑ a b data sheet Birdlife Europe (2008; data 1992–2002).
- ↑ Brewer (2001), p. 201.
- ↑ HBV (1985), Vol. 10/2, p. 986.
- ↑ Hölzinger (1999), Vol. 3.1, pp. 251f.
- ↑ Creutz (1986), p. 60.
- ↑ Creutz (1986), p. 63.
- ↑ HBV (1985), Vol. 10/2, p. 1005.
- ↑ HBV (1985) Vol. 10/2; P. 1000.
- ↑ Bezzel, Prinzinger (1990), p. 153.
- ↑ HBV (1985), Vol. 10/2, p. 989.
- ↑ Hölzinger (1999), p. 250.
- ↑ HBV (1985), Vol. 10/2, p. 991.
- ↑ Hegelbach (2001), p. 285.
- ↑ Hölzinger (1999), Vol. 3.1, p. 251.
- ↑ Brewer (2001), p. 19.
- ↑ HBV (1985), Vol. 10/2, p. 95.
- ↑ Lauga et al. (2005), p. 261.
- ↑ Bauer, Berthold (1997), p. 322f.
- ↑ Creutz (1986), p. 130.
- ↑ HBV (1985), Vol. 10/2, p. 999.
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