Japanese White-eye (Zosterops japonicus) - HBW 13, p. 445

Taxonomy: Zosterops japonicus Temminck and Schlegel, 1845, Decima, Nagasaki, Japan.
Forms a superspecies with Z. meyeni and Z. palpebrosus, and sometimes considered conspecific with either or with both, but all appear morphologically distinct; hybrids with Z. palpebrosus found in S China and N Vietnam; sometimes only N race batanis of Z. meyeni placed within present species. Affinity to Z. erythropleurus unclear. Geographical variation possibly partly clinal, as N races large, dark and with somewhat brownish or buffy flanks, whereas smallest and brightest races occur in S of range (Hainan I); curiously, races on small islands surrounding Japan (insularis, stejnegeri and alani) are larger and have longer, broader bill than average-sized nominate in mainland Japan; further study required. Races stejnegeri and alani interbreed in Bonin Is (where both were introduced); hybrids named as boninsimae. Other proposed races are yesoensis (described from Muroran, on Hokkaido), which is synonymized with nominate, and, in S Ryukyus, iriomotensis (from Iriomote) and yokakuni (Yonaguni-jima), which are subsumed in loochooensis. Eight subspecies recognized.