Malacorhynchini
| Malacorhynchini | ||||||||||
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Rose-eared duck , drake |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Malacorhynchini | ||||||||||
| Boetticher , 1950 |
Malacorhynchini are a tribe of the duck birds (Anatidae). This tribe has only two extant species: the pink-eared duck , one endemic breeds of ducks of the Australian fauna , and the Salvadori , which occurs only in the difficult to access regions of New Guinea highlands. The latter species was not scientifically described until 1894; the first cleavage was found in 1959. Malacorhynchus scarletti , the third species to be assigned to this tribe, once lived in New Zealand and was already exterminated by the Maori .
Systematics
Bradley C. Livezey assumed the relationship between the two species in the 1990s on the basis of morphological similarities. Similarities exist with regard to the white drawing on the back and the black and white drawing of the flanks. The downy cubs have a color drawing that differs from the other duck species, which clearly distinguish the Anatinae and also the feather egg white.
Traditionally, the rose-eared duck is viewed 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 hem-billed ducks , which are, however, now counted among the demi-geese . The common features of the Salvadoran, torrent and pack-billed duck include the lack of seasonal dimorphism , the fundamentally monogamous behavior, the aggressive defense of the breeding area, the presence of wing spurs, the care of the young birds by both parents and a clutch that consists of only a few however, there is large eggs. These common characteristics, however, probably developed from the fact that all three ducks live on fast-flowing waters and are considered a result of adaptation to this, for ducks extreme habitat.
Duration
The rose-eared duck is a species that is widespread in Australia. Its population fluctuates greatly. The ornithologist Hartmut Kolbe , who specializes in duck birds , described the spatula-billed duck as the most extreme invasive anatids in Australia. Where ecologically favorable conditions prevail, mass accumulations of this type occur very quickly. Inland and brackish water lakes as well as flooded grasslands are ecologically beneficial. In regions where there has been heavy local rainfall, large numbers of these birds arrive very quickly. If the flooded areas offer them suitable living conditions, they immediately begin courtship and mating. With the falling water levels, their preferred food - namely zoo and phytoplankton - is concentrated in ever smaller bodies of water. Most of the time the young birds have hatched by this time. After the white-throated duck, the rose-eared duck is the most common species in Australia with a population that exceeds 1 million individuals in years that are favorable for this species of duck.
The Salvadoran duck, on the other hand, is a very rare species, which, like the common brook duck and black-billed duck, suffers from the fact that rainbow trout have been introduced into their habitat. This was done to improve the protein supply for the people living there. For the Salvadoran ducks, who feed on the larvae of quiver flies and mayflies , among other things , this means increased food competition. The IUCN therefore classifies this species as endangered ( vulnerable ). It has been under protection since 1968, but is still hunted by the indigenous people of New Guinea. The greatest danger, however, comes from habitat degradation along the rivers where this duck lives.
swell
Single receipts
literature
- Janet Kear (Ed.): Ducks, Geese and Swans. Oxford University Press, 2005, ISBN 0-19-854645-9 .
- Hartmut Kolbe: Die Entenvögel der Welt , Ulmer Verlag 1999, ISBN 3-8001-7442-1