Tree stilt

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Tree stilt
Forest Wagtail 4024 cropped.jpg

Tree stilt ( Dendronanthus indicus )

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Passeroidea
Family : Stilts and pipiters (Motacillidae)
Genre : Dendronanthus
Type : Tree stilt
Scientific name of the  genus
Dendronanthus
Blyth , 1844
Scientific name of the  species
Dendronanthus indicus
( Gmelin , 1789)

The tree stilt ( Dendronanthus indicus ) is a songbird species from the family of stilts and pipiters and the only species in the genus Dendronanthus . It is common in large parts of China , Korea , southwestern Japan and the southern Russian Far East , where it inhabits forests of all kinds. In contrast to other stilts, it avoids open landscapes and mostly moves in the cover of trees and bushes. The species is monotypical . It is classified as not threatened by the IUCN .

description

Tree stilt in rear view

At 16 to 17.5 cm, the tree stilt is about the same size as a wagtail , with a tail length of 6.4 to 7.2 cm but shorter-tailed. The wing length is between 74 and 85 mm. The rather long legs are flesh-colored, the feet a little gray. The 32 to 40 mm long upper beak is dark gray, the lower beak matt pink. The sexes do not differ.

In the adult dress , the gray-brown coloring of the entire upper side plays slightly into olive green. The stripe above the eyes is whitish, the eye shows a light ring and the iris is dark brown. The reins are dark, the ear covers sometimes a little lighter. The chin and throat are set off - sometimes by an indistinct streak of beard - and, like the rest of the underside, whitish. On the throat, breast and under tail-coverts there is sometimes a yellowish tinge, on the flanks a yellow-brown tinge. A matt black, crescent-shaped band runs over the upper breast, and below it a second, mostly blackish-brown, interrupted and sometimes somewhat spotty band. The upper one is sometimes pulled down a little in the middle of the chest, in some birds the bands merge on the sides. The marginal-coverts are colored like the upper side, the remaining wing-coverts are black-brown and have broad, yellowish-white tips that form two parallel wing bands. The screen springs are brown-gray with an individual black component on the centers. The black-brown hand wings are narrow on the outer flag, the arm wings wider but more diffuse yellowish-white lined. They show a whitish base, which is visible as a light field when the wing is folded. The upper tail-coverts are dark olive-brown, the middle pair of control feathers gray-brown. The three following pairs are black-brown and the outer two are predominantly white with a black part at the base, so that the outside of the tail looks white.

The youth dress is similar to the adult dress, but the top is more brown, the chest bands are usually narrower and the lower chest band is often hardly present.

voice

The singing differs significantly from that of other stilts. It is reminiscent of that of the great tit , but is slower and smack-like rough. It consists of series of 3–7, rarely up to 11 high, two-syllable phrases that can be described with zli-zlu . The reputation is a high- pitched pick that is often brought up in two syllables. A high, thin tsiiii or tzriii can be heard as an alarm call .

Spreading and migrations

The distribution ranges from about 49 ° N in the southern Russian Far East over northeast China and Korea south over the extreme southwest of Japan ( Honshū and Kyushu ) as well as into the Chinese provinces of Fujian , Hunan , north Guizhou , southeast Sichuan , and possibly to northeast Yunnan . Allegedly there are also breeding occurrences in northern Assam and in western Myanmar .

The tree stilt is a migratory bird that overwinters in Southeast Asia. The wintering areas begin south of the brood distribution in China and extend over Indochina and the western Philippines south to Borneo and Java , west to Bangladesh . Another wintering area is on the southwest coast of the Indian subcontinent and on Sri Lanka . The migration begins in late August, peaks in the northern range in September, in China and Japan in October. The birds can be found in the winter quarters between the end of September and April and leave them in March. The peak of the withdrawal in Indochina is in the second half of March. In Japan the species arrives at the end of April to the beginning of May, in the Russian Far East from the beginning of May.

Systematics

The tree stilt was first described by Johann Friedrich Gmelin as a species from the genus Motacilla , but later placed in a genus of its own by Edward Blyth due to numerous unique selling points . The phylogenetic relationships to other genera of the family are, however, still unexplained , despite an examination of the mitochondrial DNA . In addition to the unique drawing of the plumage, the tree stilt differs from other stilts due to the coloring of the beak, feet and legs and the lateral movement of the tail. The species is also tied to the forest and can often be found on trees in which it - unlike all other members of the family - builds its nest. The carpal region of the nestlings is feathered and the young birds moult very early into adult plumage. The drawing of the eggs, which is reminiscent of some finch species , and the song also differ.

literature

  • Per Alström, Krister Mild: Pipits and Wagtails of Europe, Asia and North America , Helm Identification Guides, Christopher Helm, London 2003, ISBN 0-7136-5834-7

Individual evidence

  1. ↑ Alström et al., Pp. 428 and 430f (see literature)

Web links

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