The Japanese murrelet or crested murrelet (Synthliboramphus wumizusume) is a small seabird in the auk family that occurs along the remote rocky coasts and in the offshore waters of Japan, and may also be found after the breeding season as far as Sakhalin to the north and in particular off South Korea.[3] With a small and declining population, estimated as of 2017 to total 2,500–10,000 individuals, it is the rarest alcid, and the most at risk of extinction.[4]
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.[7][10] The s and z in the Japanese name were reversed by Temminck in the scientific name.[11]
Description
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).[7][12] 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.[7] 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.[7] 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,[12] although this again is absent in winter.[7] Juveniles resemble winter adults, though the head and upperparts are somewhat browner.[7]
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」).[10][11]
It nests in rocky crevices and hollows, in the gaps between piles of stones, and among the grasses on uninhabited islands.[12] Typically two eggs are laid, a week apart, from late March to early April, though this takes place a little earlier on Tori-shima, at the southern end of its breeding range.[11][12] Month-long incubation duty is shared almost equally by both parents.[10][12] The precocial chicks are not fed in the nest, but leave it together with their parents on the second night after hatching.[10]
On the 2016 Red List of China's Vertebrates, Synthliboramphus wumizusume (Chinese: 冠海雀) has the status Data Deficient;[19]: 515 with a visiting population of less than 1% of the species, it is included on the 2016 Red List of Birds of Taiwan with the status NA ("Not Applicable").[20]: 38 As a rare, "migratory" species with local distribution and declining numbers, Synthliboramphus wumizusume (Russian: Хохлатый старик) is included in the 2016 Red Data Book of Sakhalin Oblast in Category 1,[21]: 121 in the 2019 Red Data Book of Khabarovsk Krai, as a vary rare vagrant at the edge of its range, also in Category 1,[22]: 469 and in the 2005 Red Data Book of Primorsky Krai in Category 3.[21][23] In the 2011 Red Data Book of Endangered Birds in Korea, with mention of occasional breeding on offshore islands (Gugul Island and the Liancourt Rocks), Synthliboramphus wumizusume (Korean: 뿔쇠오리) has the status Endangered.[24]: 59–61 On the 2020 Japanese Ministry of the EnvironmentRed List, Synthliboramphus wumizusume (Japanese: カンムリウミスズメ) has the status Vulnerable,[25] as it had done on the 1991, 1998, and 2007 editions.[12][25] In Mie Prefecture, it has been designated a Prefectural Endangered Species.[26]
^ abPiatt, J.F.; Gould, P.J. (October 1994). "Postbreeding Dispersal and Drift-Net Mortality of Endangered Japanese Murrelets". The Auk. 111 (4): 953–961. doi:10.2307/4088827. JSTOR4088827.
^Takeishi Masayoshi (1987). 福岡県小屋島におけるカンムリウミスズメの大量姥死について [The mass mortality of Japanese Murrelet Synthliboramphus wumizusume on the Koyashima lslet in Fukuoka] (PDF). Bulletin of the Kitakyushu Museum of Natural History (in Japanese). 7: 121–131.
^Zhigang Jiang; et al. (2016). 中国脊椎动物红色名录 [Red List of China's Vertebrates]. Biodiversity Science (in Chinese and English). 24 (5): 500–551. doi:10.17520/biods.2016076.