Anatinae
| Anatinae | ||||||||||
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Mallard -pair ( Anas platyrhynchos ) |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Anatinae | ||||||||||
| Leach , 1820 |
The Anatinae are a subfamily of the duck birds , the fine-tuning of which is carried out differently by taxonomists and whose genus or species affiliation is in some cases strongly in upheaval due to new morphological findings. In the past, all "non-geese" among the duck birds were assigned to this subfamily, so that the taxon Anatinae was appropriately assigned the German name ducks. In the meantime, the demi-geese and rowing ducks have been granted a special position within the Anseriformes family, so that the swimming ducks, diving ducks, sea ducks and sawducks as well as two little-known genera as Anatinae remain. The article follows the delimitation proposed by the ornithologist Janet Kear , who specializes in duckbirds, in the treatise, which is regarded as the standard work. This assignment is not yet to be regarded as generally valid. A number of zoologists prefer other compositions of the Anatinae.
General characteristics of the appearance
The ducks assigned to the subfamily Anatinae have uniform body characteristics, as they are found either in all or in a large number of other species belonging to the Anseriformes. These include the compact physique, the short legs, which are set relatively far back on the body and which lead to the characteristic waddling gait, the beak, which has horn ridges on the inner edge of the beak and a horn cap at the tip of the beak, and the webbed front toes of the Feet. The chicks have a dense dune dress and flee the nest, which can swim a few hours after leaving the egg. Characteristic body features and behaviors are more likely to be found in the individual branches.
Tribe swimming ducks (Anatini)
see also main article: Swimming ducks
This species-rich tribe includes ducks, which are characterized, among other things, by a pronounced seasonal and sexual dimorphism . In many species the males have a strongly contrasting splendor. When resting, like the females, they have brown, inconspicuous plumage. Swimming ducks feed on grounding . You stand with your head down in the water so that your neck and chest are also in the water. The rest of the torso and legs keep their balance through slight leg movements. For this reason, the term “ gundog” has established itself for this tribe , which a number of ornithologists consider to be a better and more descriptive choice than the term “swimming duck”. Swimming ducks are basically able to immerse their whole body in the water, but they usually only use this ability to avoid enemies.
It is characteristic of swimming ducks that the body's center of gravity is shifted towards the center of the body so that the end of the body is slightly lifted out of the water. Basically, swimming ducks have a specifically lighter body weight than diving ducks. They are therefore higher in the water than this. It is also typical of green ducks that they are able to rise directly from the water into the air without needing a contact surface.
The anatomical peculiarities of the swimming ducks include the thin rear toe and the syrinx at the end of the windpipe , which is expanded to form a drum and, in the case of the gudgeon duck, is completely ossified.
The mallard , which can be found regularly on the water in urban green spaces, is probably the best-known swimming duck . Other species native to Europe are whistling , gadfly , krick , pintail , teal and shoveler . The golden ducks, which in the past were often run as an independent tribe, are now mostly classified as swimming ducks, two species also as demi- geese.
Tribe diving ducks (Aythyini)
see also main article: diving ducks
The diving ducks (Aythyini) are mostly freshwater-dwelling ducks that find their food diving. The characteristic immersion movement begins with a slight lifting of the upper body out of the water, the neck is curved downwards, but stretched. With a simultaneous blow of the feet, the duck then dips into the water. Typical of the diving ducks are the legs that are set very far back, which give them the strength they need to dive very deeply into the water. Scoter and velvet ducks regularly reach water depths of 30 meters. On land, diving ducks are usually clumsy due to their leg position and have a gait that appears awkward to humans.
Diving ducks are on average slightly smaller than swimming ducks and have a more compact body shape. The body's center of gravity is shifted far back. Diving ducks have a higher specific weight and lie deeper in the water compared to swimming ducks. Your back is rounded. In order to rise from the water into the air, they usually run against the wind with violent wing flapping, whereby the respective distance is influenced by the body mass. In some of the species, as with the swimming ducks, there is a seasonal and sexual dimorphism. The company, a duck birds of South America rosy-billed pochard , African pochard , the hardhead and the Madagascar Pochard and the New Zealand diving duck have a plumage on without strong seasonal change. They are therefore also referred to as an annual dress. In other males of diving ducks, too, the differences between breeding and resting plumage are not very pronounced. The bog duck is the only one of the European Anatinae species in which sexual dimorphism is only weakly pronounced.
The thickened rear toe is one of the anatomical features of diving ducks.
The better-known diving ducks, which are among the regular breeding birds in Europe, include the tufted , mountain and pochard .
Tribes sea ducks and sawsmen
see also main article: Sea ducks and sawdots
The sea ducks and sawyers (mergini) comprise, in addition to the sawsmen, a number of diving ducks, which are often, but not always, adapted to a life on the seashore. Goldeneye and eider are examples of such Anatinae species. In their appearance, sea ducks and sawdocks are similar to diving ducks. The saws are characterized by their thin, very narrow beak. The nail at the tip of the beak is bent over like a hook, while the edges of the upper and lower beak have sharp, slightly pointed teeth.
The diet of the species belonging to the sea ducks and sawdaws is predominantly animal. The food components include aquatic insects, mollusks, echinoderms and fish. The King Eider should in so-called Gradationsjahren where an overabundant supply of small mammals is present, this occasionally eat. In some species, the seeds and green components of aquatic plants are added.
Tribe Malacorhynchini
see also the main article Malacorhynchini
As the fourth tribe after Kear, the Malacorhynchini with the two little-known species of rose-eared duck and Salvadoriente are counted among the Anatinae. The Salvadoriente is a species of duck whose distribution is limited to the inaccessible highland regions of New Guinea. It was not scientifically described until 1894; the first clutch was found in 1959. The rose-eared duck is a species of duck from Australia. Malacorhynchus scarletti , the third species assigned to this tribe, once lived in New Zealand and was already exterminated by the Maori . Bradley Livezey assumed the relationship between the two species on the basis of morphological similarities. Traditionally, the rose-eared duck is regarded either as a representative of the swimming ducks or as an isolated species at the base of the duck birds, while the Salvadoran duck, as an inhabitant of fast-flowing brooks, shows similarities in behavior to the torrent and fringed-billed ducks , which are, however, counted among the half geese .
The moult
Most of the duck species of the Anatinae change their plumage twice a year, whereby the change of plumage in males and females is slightly offset from one another. The moult before the breeding season is known as the prenuptial moult and is the change from the dormant to the splendor or breeding plumage. After the breeding season, this dress is changed back to the resting dress in the postnuptial moult. Extensive moulting studies are not available for all Anatinae species. The moulting process is best investigated in the mallard, although there are considerable individual and population-specific differences in the time course of the moulting within this species. In Central European mallards, the drakes change their wing plumage at the beginning of the preenuptial moult between July and August and are then unable to fly for three to five weeks. Then the rest of the plumage is changed, which lasts until the beginning of December. From then on, the ducks wear the fully developed splendor or brood dress. The postnuptial moult begins in the middle of May with Mallard Tucks with the shedding of the central control feathers while the females are still breeding. The moulting of the small plumage then follows. In females, the moulting takes place in September and the change of small plumage in breeding plumage between October and November.
voice
Anatinae have a wide range of vocalizations. The sounds are made in the syrinx at the end of the windpipe . The calls of the males and females can differ considerably, which is usually accompanied by a difference in the structure of the larynx. In a number of species, the voice is inconspicuous. Especially in the tribe of sea ducks and sawsmen, there are species whose calls can be heard from far and wide. The uh-huh-uu of the eider , which can still be heard from a great distance, is reminiscent of the call of the stock dove. From a distance, the sonorous garu-kolik of the long-tailed drake courting in groups are reminiscent of bright bells. Most of the duck calls are less melodic , like the mallard's räb-räb-rab . The calls of the females are generally less noticeable than those of the drakes.
Anatinae also produce a number of instrumental sounds . This includes the dull, tinkling wich wich wich ... , which is characteristic of the flight of mallards and is produced with the wings. During courtship, male mallards show ritualized sham cleaning, in which their beak touches the keels of the wings of their hands from behind. This creates a rattling rrp sound. Other anatinae produce loud water splashing during courtship by hitting the water surface with their feet or flapping their wings on the water during immersion.
nutrition
The different beak shapes of the Anatinae species already indicate the different feeding strategies of the individual species. In the following, this is shown using four species as an example, whose clearly different beak shapes have characteristics of adaptation to their respective diet.
The counting of the Gründel ducks Löffelente has a wide front expiring, chunky Schnabel, a particularly high number located at the edges of fine skin lamellae. Water close to the surface is chattered through by it, whereby the absorbed water is pushed out sideways through the comb-like lamellae. It takes in insects, snails, worms as well as floating seeds and green plant components.
The counting of the diving ducks Moorente has a uniformly wide beak with a well-trained horn tip. It can absorb floating plant components on the surface. As a rule, however, it emerges and uses its beak to pick up seeds, rhizomes, tubers and plant components of the submerged aquatic vegetation as well as the plants of the floating leaf zone. It also consumes small water snails and free-swimming aquatic insects, even if the animal food component makes up a smaller proportion of its food overall. Diving ducks are generally better adapted to life on the water than green ducks. Many of them are vegetarian. In many regions of the world they occupy an ecological niche similar to that of swans. While they look for food underwater with the help of their long swans, the diving ducks dive.
The common scoter, which belongs to the sea ducks and sawducks, has a short and strong beak. It specializes in diving on the seabed, picking up mussels and, to a lesser extent, snails and chopping them up with its powerful beak. Crustaceans, annelids and echinoderms and, in summer, to a lesser extent, plant components are also part of their diet. Fish, on the other hand, are only very rarely consumed by it. The goosander, on the other hand, feeds exclusively on fish.
swell
Single receipts
- ↑ Rutschke, p. 10
- ↑ Rutschke, p. 12
- ↑ Rutschke, p. 288
- ↑ Kolbe, p. 193
- ↑ Rutschke, p. 23
- ↑ Rutschke, p. 22 and Kolbe, p. 211
- ↑ Rutschke, p. 15
- ↑ 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. 57
- ↑ Kear, p. 621
literature
- Janet Kear (Ed.): Ducks, Geese and Swans . Oxford University Press, 2005, ISBN 0-19-854645-9
- Manfred Kästner: Gründelenten , Urania Verlag, Leipzig 1994, ISBN 3-332-00546-4
- Hartmut Kolbe: Die Entenvögel der Welt , Ulmer Verlag 1999, ISBN 3-8001-7442-1
- Erich Rutschke: The wild ducks of Europe , Aula Verlag, Wiesbaden 1990, ISBN 3-89104-449-6
