Japanese Murrelet

Identificazione

The Japanese murrelet is a smallish seabird 24–26 cm (9.4–10.2 in) in length, with a wingspan of 43 cm (17 in), and weighing some 164–183 g (5.8–6.5 oz). Its upperparts are blackish and bluish grey, its throat and underparts white, legs and feet a yellowish grey, and short, thick bill a bluish grey, the culmen being darker; the iris is a dark brown. The black head features a white stripe from the top of each eye that meets on the nape, although this is less visible in winter. It may be distinguished from the Ancient murrelet (Synthliboramphus antiquus), which also occurs in much of its range, in particular by its summer crest of black feathers 3–5 cm (1.2–2.0 in) in length, although this again is absent in winter. Juveniles resemble winter adults, though the head and upperparts are somewhat browner.<p>The Japanese murrelet's calls include a quiet "ch-ch-chi-chi" (「チッ、チッ、チ、チ」), while in flight, "peee-p-p-p" (「ピィー、ピッ、ピッ、ピッ」) and "jee-jujjujju" (「ジージュッジュッジュッ」), and while at the nest "jijiji-pipewpipewkukukuku" (「ジジジ、ピピュウピピュウクククク」), "gugguwa-gugugu" (「グッグワ、グググ」), and "jukkukuwa-kuwakuwakuwa" (「ジュッククワ、クワクワクワ」).

Tassonomia

The Japanese murrelet is a monotypic species first described by Coenraad Temminck, as Uria wumizusume, in the text accompanying an 1836 livraison in the ongoing series Nouveau recueil de planches coloriées d'oiseaux.: 46  The following year, Johann Friedrich von Brandt erected the genus Brachyramphus and subgenus Synthliboramphus, transferring to it the Japanese murrelet, to which he gave the new specific name temminckii.: 346–7  Synthliboramphus has since been raised to generic rank, the specific name wumizusume having priority in accordance with Article 23 of the International Code of Zoological Nomenclature.<p>In its native Japan, the Japanese murrelet is known as the kanmuri-umisuzume or "crested sea sparrow" (冠海雀), umisuzume being the vernacular name for the ancient murrelet (Synthliboramphus antiquus), from which it may be distinguished by its black crest. The s and z in the Japanese name were reversed by Temminck in the scientific name.

Nome scientifico

Synthliboramphus wumizusume

Autorità

(Temminck, 1836)

Ordine

Caradriformi

Famiglia

Alcidi

Genere

Synthliboramphus

Areale e habitat

The Japanese murrelet occurs in the boreo-cool and temperate-subtropical waters of the northwest Pacific. It breeds on the small rocky islets and coasts of Japan from Nanatsujima in Ishikawa Prefecture in the north to Tori-shima in the Izu Islands of Tokyo Metropolis to the south, the chief areas being Birōjima in Miyazaki Prefecture, followed by the Izu Islands, and other small islands such as Mimiana Island (耳穴島) in Mie Prefecture, and Kōshima (幸島) in Kōchi Prefecture; family groups have been reported from the waters off Yashima [ja] in Kaminoseki at the western end of the Seto Inland Sea, and a pair with two chicks has been collected off the south coast of Korea, across the Tsushima Strait. After breeding, it disperses along Honshū and Kyūshū, in the warm waters of the Kuroshio Current and Tsushima Current, with records from Iturup and Shikotan in the Southern Kuriles, Sakhalin, Peter the Great Bay and Olga Bay in Primorsky Krai, Fujian (1894), South Korea, and Taiwan (1973). It flies back around December and winters mostly offshore from its breeding locations.

Areale riproduttivo

PAL : w North Pacific coasts: islands off w Honshu, Kyushu and Izu Is. (c, s Japan), s of Korean Pen. and ?far se Russia

Areale non riproduttivo

to Hokkaido (n of Japan) and se of Japan

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in diminuzione.

Tendenza della popolazione

in diminuzione