Pouillot d'Ijima

Identification

Ijima's leaf warbler is a small passerine with a total length of 11.5 cm (4.5 in) and weight of around 10 g (0.35 oz). The crown and nape are a greenish-grey, upperparts a bright olive green, flanks greyish, and underparts white. It has a long white or buffish-white supercilium, blackish eyestripe, and dark brown iris. The beak is relatively long and "broad-based", the upper mandible dark brown, the lower yellowish, and the legs and feet a pinkish brown.<p>The warbler is similar in appearance to the eastern crowned warbler (Phylloscopus coronatus), from which it may be distinguished visually by the absence of a central stripe on its crown and by its paler yellow undertail coverts. Its song and calls, which include "swss, swss, swss", "swee-swee-swee-swee-swee", "shwee-it, shweet, shweet, shweet", and a soft "se-chui, se-chui, se-chui" and "phi-phi-phi", also differ from those of the eastern crowned warbler.

Taxonomie

Ijima's leaf warbler is a monotypic species first described by Leonhard Stejneger in 1892, based on three specimens collected in the spring of 1887 by Namie Motokichi [ja] on Miyake-jima and Nii-jima, in the Izu Islands of Tokyo. Initially given the scientific name Acanthopneuste ijimae by Stejneger, Momiyama Tokutarō [fi] followed suit in a 1923 paper on the birds of Izu Ōshima.: 206  In a 1926 paper on a collection of birds from the Ryūkyū Islands, Kuroda Nagamichi treated the warbler instead as a subspecies of the western crowned warbler, as Acanthopneuste occipitalis ijimae,: 85  Yamashina Yoshimaro following suit in 1935.: 431  In 1938, Claud Ticehurst treated the warbler as a "race" of the eastern crowned warbler (Phylloscopus coronatus), as did Allan Robert Phillips in 1947, based on three specimens from the southern part of Okinawa Island, the combination being Phylloscopus coronatus ijimae. In 1953, citing differences in songs and nesting behaviours, Oliver L. Austin and Kuroda Nagahisa elevated the warbler to specific rank, with the binomial Phylloscopus ijimae,: 543  a treatment followed the next year by Charles Vaurie: 22  Kenneth Williamson treated the warbler as a subspecies of the pale-legged leaf warbler, under the combination Phylloscopus tenellipes ijimae; however, due to differences in its vocalizations, nesting preferences, and DNA, the warbler has again been elevated to species rank, as Phylloscopus ijimae. The specific name honours Ijima Isao, for his contributions to Japanese ornithology.

Nom scientifique

Phylloscopus ijimae

Autorité

(Stejneger, 1892)

Ordre

Passériformes

Famille

Phylloscopidae

Genre

Phylloscopus

Répartition et habitat

Ijima's leaf warbler breeds in the summer in the Izu Islands, from Izu Ōshima to Aogashima, and also on Nakanoshima in the Tokara Islands. In the spring and autumn, there are records of its presence from Honshū (Shizuoka, Aichi, and Wakayama prefectures), Mizunoko-jima, Tanegashima, Yakushima, and Okinawa Island and the Yaeyama Islands in the Ryūkyūs. Its wintering grounds are poorly understood; a small number may overwinter in the Izu Islands (Miyake-jima and Hachijō-jima) and Ryūkyū Islands, while there are also records from Taiwan and Luzon in the northern Philippines. It inhabits the "lowland deciduous and mixed subtropical evergreen forest" and laurel forest, including the forest edge, stands of alder (Alnus) and bamboo, and shrubland.

Aire de reproduction

PAL : Izu Is. (se of Honshu, e Japan) and Nakanoshima, Tokara Is. (far n Ryukyu Is., s Japan)

Aire hors reproduction

poorly known; likely Ryukyu Is. (s Japan), Taiwan and Luzon (n Philippines)

Migration

Migrateurs complets

Comportement

Mode de migration: Migrateurs complets.

Conservation

Tendance de la population: en déclin.

Tendance de la population

en déclin