Ijima's leaf warbler

(Redirected from Izu Leaf-warbler)

Ijima's leaf warbler (Phylloscopus ijimae) (also known as Izu leaf warbler, Ijima's willow warbler or Ijima's warbler) is a species of Old World warbler in the family Phylloscopidae. The species is native to Japan, where it has been designated a Natural Monument under the 1950 Law for the Protection of Cultural Properties,[6] with records also from Taiwan and the Philippines.[1]

Ijima's leaf warbler
Warbler in Taiwan (April 2021)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Phylloscopidae
Genus: Phylloscopus
Species:
P. ijimae
Binomial name
Phylloscopus ijimae
(Stejneger, 1892)
Synonyms

Acanthopneuste ijimae (protonym)[2]
Acanthopneuste occipitalis ijimae[3]
Phylloscopus coronatus ijimae[4]
Phylloscopus tenellipes ijimae[5]

Taxonomy

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Ijima Isao (1861–1921), whose name the warbler bears[2]

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.[2] Initially given the scientific name Acanthopneuste ijimae by Stejneger,[7] Momiyama Tokutarō [fi] followed suit in a 1923 paper on the birds of Izu Ōshima.[8]: 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,[3]: 85  Yamashina Yoshimaro following suit in 1935.[9]: 431  In 1938, Claud Ticehurst treated the warbler as a "race" of the eastern crowned warbler (Phylloscopus coronatus),[5][10] as did Allan Robert Phillips in 1947, based on three specimens from the southern part of Okinawa Island, the combination being Phylloscopus coronatus ijimae.[4] 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,[11]: 543  a treatment followed the next year by Charles Vaurie[12]: 22  Kenneth Williamson treated the warbler as a subspecies of the pale-legged leaf warbler, under the combination Phylloscopus tenellipes ijimae;[5] however, due to differences in its vocalizations, nesting preferences, and DNA,[7] the warbler has again been elevated to species rank, as Phylloscopus ijimae.[13] The specific name honours Ijima Isao, for his contributions to Japanese ornithology.[2][14]

Description

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The eastern crowned warbler (Phylloscopus coronatus) may be distinguished by its crown stripe[15]

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).[16] The crown and nape are a greenish-grey, upperparts a bright olive green, flanks greyish, and underparts white.[7] It has a long white or buffish-white supercilium, blackish eyestripe, and dark brown iris.[7] The beak is relatively long and "broad-based", the upper mandible dark brown, the lower yellowish, and the legs and feet a pinkish brown.[1][7]

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.[7][15] 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",[7] also differ from those of the eastern crowned warbler.[17]

Distribution and habitat

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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.[16][18] 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.[16][18] Its wintering grounds are poorly understood; a small number may overwinter in the Izu Islands (Miyake-jima and Hachijō-jima[17]) and Ryūkyū Islands, while there are also records from Taiwan and Luzon in the northern Philippines.[15][18] 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.[15][18]

Ecology

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Insects form the principal component of its diet — when written in kanji (飯島虫喰),[17] the warbler's Japanese name reads as "Ijima's insect-eater" — which also includes seeds.[18] For these it forages, singly or in small groups (sometimes including other species, in particular long-tailed tits (Aegithalos caudatus)), on lower branches, in the forest canopy, and on the ground, and it may also take prey in mid-air.[18][19]

The breeding season is from April to June or July.[16][18] Nests are built some 0.5–2 m (1 ft 8 in – 6 ft 7 in) from the ground,[7] on broad-leaved trees and in bamboo (this nesting behaviour differs from that of the eastern crowned warbler, which nests on the ground and in earthen banks).[18] The clutch size ranges from two to four eggs, with three or four the most common.[18]

Conservation

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The declining population, thought to total fewer than 10,000 individuals,[1] is threatened by habitat loss and fragmentation.[7][15] In addition, the availability of prey may be impacted by the use of pesticides.[18] The species was badly affected by the eruption of Miyake-jima in 2000.[18]

With an estimated 3% of the global population, Phylloscopus ijimae (Chinese: 飯島柳鶯) is included on the 2016 Red List of Birds of Taiwan with the status "vulnerable".[20]: 38  (The species is also included on the 2016 Red List of China's Vertebrates (with the vernacular name 日本冕柳莺), with the status "near threatened".[21]: 523 ) In the Philippines, the species is included on the National List of Threatened Fauna, as a migrant bird on Luzon, with the status "vulnerable".[22] On the 2020 Japanese Ministry of the Environment Red List, Phylloscopus ijimae (Japanese: イイジマムシクイ) has the status "vulnerable",[23] as it had done also on the 1998 and 2007 editions.[16]

See also

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References

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  1. ^ a b c d BirdLife International (2016). "Phylloscopus ijimae". IUCN Red List of Threatened Species. 2016: e.T22715353A94449596. doi:10.2305/IUCN.UK.2016-3.RLTS.T22715353A94449596.en. Retrieved 3 June 2022.
  2. ^ a b c d Stejneger, L. (1892). "Two additions to the Japanese avifauna, including description of a new species". Proceedings of the United States National Museum. 15 (906): 371–373.
  3. ^ a b Kuroda Nagamichi (1926). "On a small collection of Birdss from the Riu Kiu Islands" 琉球孤島産鳥類の小採集物に就て [On a Small Collection of Birds from the Riu Kiu Islands]. Japanese Journal of Ornithology (in English and Japanese). 5 (22): 79–95. doi:10.3838/jjo1915.5.22_79.
  4. ^ a b Phillips, A.R. (1947). "Notes on Phylloscopus coronatus ijimae". The Auk. 64 (1): 127–128. doi:10.2307/4080070. JSTOR 4080070.
  5. ^ a b c Williamson, K. (1976). Identification for Ringers 2: The Genus Phylloscopus. British Trust for Ornithology. p. 44. CiteSeerX 10.1.1.566.2944.
  6. ^ イイジマムシクイ [Ijima's leaf warbler] (in Japanese). Agency for Cultural Affairs. Retrieved 4 June 2022.
  7. ^ a b c d e f g h i del Hoyo, J.; Elliott, A.; Christie, D.A, eds. (2006). Handbook of the Birds of the World. Vol. 11: Old Worlf Flycatchers to Old World Warblers. Barcelona: Lynx Edicions. pp. 667–668. ISBN 84-96553-06-X.
  8. ^ Momiyama Tokutarō [in Finnish] (1923). 伊豆大島に於ける鳥類 [Birds on Izu Ōshima]. Japanese Journal of Ornithology (in Japanese). 3 (14): 196–213. doi:10.3838/jjo.3.14_196.
  9. ^ Yamashina Yoshimaro (1935). "On Acanthopneuste occipitalis ijimae and Locustella ochotensis pleskei" イヒジマメボソとウチヤマセンニフ [On Acanthopneuste occipitalis ijimae and Locustella ochotensis pleskei]. Japanese Journal of Ornithology (in Japanese). 8 (40): 431–439. doi:10.3838/jjo1915.8.40_431.
  10. ^ Ticehurst, C.B. (1938). A Systematic Review of the Genus Phylloscopus. London: Trustees of the British Museum. p. 162.
  11. ^ Austin, O.L.; Kuroda Nagahisa (1953). "The Birds of Japan: their status and distribution". Bulletin of the Museum of Comparative Zoology. 109 (4): 277–637. hdl:2246/4956.
  12. ^ Vaurie, C. (1954). "Systematic Notes on Palearctic Birds. No. 9. Sylviinae: the genus Phylloscopus". American Museum Novitates (1685): 1–23. hdl:2246/4956.
  13. ^ Gill, F.; Donsker, D.; Rasmussen, P., eds. (2022). "IOC World Bird List v12.1: Bushtits, leaf warblers, reed warblers". IOC World Bird List. Retrieved 4 June 2022.
  14. ^ Beolens, B.; Watkins, M.; Grayson, M. (2014). The Eponym Dictionary of Birds. Bloomsbury. pp. 274–275. ISBN 978-1-4729-0573-4.
  15. ^ a b c d e イイジマムシクイ [Phylloscopus ijimae] (in Japanese). Tokyo Metropolitan Government. Retrieved 4 June 2022.
  16. ^ a b c d e Ministry of the Environment, ed. (2014). レッドデータブック2014 —日本の絶滅のおそれのある野生生物— 2 鳥類 [Red Data Book 2014 — Threatened Wildlife of Japan — Volume 2, Aves] (in Japanese). Gyōsei Corporation. pp. 218–219. ISBN 978-4-324-09896-7.
  17. ^ a b c Kabaya Tsuruhiko [in Japanese]; Matsuda Michio 松田道生 (2001). 日本野鳥大図鑑 鳴き声420 [The Songs & Calls of 420 Birds in Japan] (in Japanese). Tokyo: Shogakukan. p. 294. ISBN 4-09-480073-5.
  18. ^ a b c d e f g h i j k Collar, N.J., ed. (2001). Threatened Birds of Asia: The BirdLife International Red Data Book (PDF). Vol. B. BirdLife International. pp. 2170–2175. ISBN 0-946888-43-4.
  19. ^ Clement, P. (2006). "Ijima's Leaf Warbler Phylloscopus ijimae". Cornell Lab of Ornithology. Cornell University. Retrieved 4 June 2022.
  20. ^ Lin, R.-S.; Lu, Y.-J.; Yang, C.-H.; Tseng, T.-J.; Ko, C.-J.; Chen, W.-J. (2016). 2016臺灣鳥類紅皮書名錄 [The Red List of Birds of Taiwan, 2016] (in Chinese and English). Endemic Species Research Institute. ISBN 978-986-05-1406-3.
  21. ^ 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.
  22. ^ "National List of Threatened Fauna". Biodiversity Management Bureau. Retrieved 3 June 2022.
  23. ^ レッドリスト2020 鳥類 [2020 Red List: Birds] (in Japanese). Ministry of the Environment. 27 March 2020. Retrieved 3 June 2022.
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