Japanese wagtail
| Japanese wagtail | ||||||||||||
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Japanese wagtail ( Motacilla grandis ) |
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| Motacilla grandis | ||||||||||||
| Sharpe , 1885 |
The Japanese wagtail ( Motacilla grandis ) is a songbird species from the family of stilts and pipiters . It is endemic to the main islands of Japan , but scattered evidence of breeding has also been found from the Korean Peninsula . The black and white stilt was listed as a subspecies of the wagtail for a long time , but breeds sympatricly with the two wagtail subspecies Motacilla alba leucopsis and M. a. lugens and there are rare cases of hybridization . The species is not threatened.
description
The Japanese wagtail is similar to the eastern subspecies of the white wagtail, but with a body length of 21–23 cm it is larger, longer-legged and slightly longer-beaked in direct comparison. The wing length is between 86 and 104 mm, the tail length between 85 and 101 mm. In contrast to the wagtail, the two outer pairs of control springs are shorter than the middle one. This characteristic has the species in common with the Mamula wagtail and the Mekong wagtail . The blackish beak is between 17.5 and 20.0 mm long. Feet and legs are blackish, the iris is dark brown.
In adult males, the upper side is predominantly black; very narrow gray fringes can be seen in the fresh plumage. The white areas of the forehead, the stripe above the eyes, a crescent-shaped, narrow spot under the eye, as well as the chin and the upper throat, stand in contrast. The underside is white with a rounded, black breast shield, on the sides of which the white protrudes up to the shoulders. The marginal coverts are black, the other upper wing coverts largely white. The larger aluminum springs are black, the smaller ones white or white with gray bases. Hand and arm wings are white at the base and blackish in the distal part, with the length of the black portion increasing towards the outer hand wings. The arm wings are also bordered in white. The brown-black umbrella feathers show a white border that is narrow on the inner, wider on the middle and very wide on the outer. The middle four pairs of control feathers are black and only show narrow seams in the fresh plumage, the two outer pairs are white except for a little black on the inner vane.
The sexual dimorphism is only weak. Females are more dark gray than black on top. Young birds are gray on top with a brownish tone. The pale gray color of the breast slowly merges with the white of the underside and sometimes continues on the flanks. Birds in the first winter can only be distinguished from adults by their slightly pronounced wing characteristics.
voice
The most common call made both in flight and while waiting is a high-pitched and sharp, beeper- like bizzr or tizzr . It differs significantly from the call of the white wagtail and can best be compared with that of the Mekong wagtail within the genus.
The singing varies between simple and monotonous or complex and varied. It consists of individual tones or longer phrases that are performed with some time interval. In contrast to that of the wagtail, it contains numerous very rough and shrill tones and is reminiscent of the songs of the goldfinch and siskin .
Distribution and existence
The Japanese wagtail occurs on all main Japanese islands as well as on Sado . There are contradicting reports about breeding occurrences on the Korean Peninsula. According to some authors, the species occurs scattered as a breeding bird there, according to others, there are only occasional breeding season and winter observations. Most of the Japanese stilts are standing birds , only Hokkaidō is almost completely cleared in winter. On Honshū , the species migrates from higher altitudes in winter. Occasional winter observations scatter between the Nansei Islands and Taiwan as well as the opposite Chinese mainland.
The species is not considered endangered (“least concern”) by the IUCN . Subspecies are not described.
habitat
In contrast to the two white wagtail subspecies found in Japan, the Japanese wagtail is more closely tied to flowing waters and rarely occurs on the coast. It prefers to breed on shallow streams and rivers, lakes and ponds. In the vicinity of human settlements it occurs almost exclusively in rural hill country, but in recent years the evidence has also increased in suburbs and other urban habitats. The altitude distribution extends up to 1400 m.
Systematics
For a long time the Japanese wagtail was considered a subspecies of the white wagtail. However, it breeds sympathetically on Hokkaidō with the wagtail subspecies Motacilla alba lugens and in southern Japan for some years with the subspecies M. a. leucopsis together. In the 1970s there was only minor overlap in the distribution areas, but this has expanded due to the expansion of the first-mentioned subspecies in particular in recent years. Cases of hybridization are rare and some are believed to have been highly dissimilar individuals rather than hybrids.
Investigations of the nuclear DNA suggest that the Japanese wagtail forms a super species with the white wagtail, the Indian mamula wagtail and the African widow wagtail as well as the Mekong wagtail , which was first described in 2001 . According to studies of the mitochondrial DNA , the widow wagtail is not very closely related to the other black and white Motacilla species.
literature
- Per Alström, Krister Mild: Pipits and Wagtails of Europe, Asia and North America , Christopher Helm, London 2003, ISBN 0-7136-5834-7
Web links
- Motacilla grandis in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2009. Accessed January 9, 2011th
- Videos, photos and sound recordings for Motacilla grandis in the Internet Bird Collection
- Photos of Motacilla grandis in the Oriental Bird Club image database , accessed on January 9, 2011
- BirdLife species factsheet , accessed January 9, 2011