北海道産メジロの考察

概要

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The type of Zosterops palpebrosa yesoensis described from Muroran, Hokkaido, by the author, has recently been condidered "an abnormal colour-phase" by Udagawa ('55). (Austin Jr., '53, p. 578, had however recognized this race). His conclusion was reached by comparison of his 11 Sapporo specimens (autumn) with whe type (May), one Hakodate, two Aomori (Shimokita, October) and one Kagoshima (March) specimens. These were reexamined with the Central Honshu specimens, which he did not compare, and two others from Hokkaido (Tomakomai, May: H. Kobayashi coll.). As the result, Hokkaido birds were found to be: 1) purer green backed, 2) flanks paler with greyish wash, the middle part of the breast being largely white, and 3) throat and under tail-coverts lemon (not chrome) yellow. The color fades in spring particularly in the female as in the type specimen (see description) to which a new Tomakomai specimen is similar. However, that Aomori and Kagoshima examples (flanks clearer buff in the latter) were Hokkaido type, as pointed out by Udagawa, makes further clarification necessary as to whether they were migrants from Hokkaido or resident birds. The status in Hokkaido still remains to be studied, and autumn examples (fresh plumage) of Kagoshima population should be examined.
1955-11-15