以綜合分類學探究臺灣本島與東部三離島繡眼屬（Zosterops）之分類

Abstract

以綜合分類學（integrative taxonomy）方法結合分子遺傳、形態、行為、生態特徵等多元證據檢定物種假說，在分類學研究上尤其應用於繡眼屬（Zosterops）等具分布廣泛且輻射種化特性的類群，可以提供穩定的分類定義。根據過去基於臺灣鳥類相及親緣關係分析之結果，已知三種繡眼鳥分布於臺灣與鄰近區域，分別是斯氏繡眼（Zosterops simplex）、低地繡眼（Zosterops meyeni）和日菲繡眼（Zosterops japonicus），然而尚須多元證據以評估其物種分類地位，並進一步描述其生物地理分布。龜山島位於斯氏繡眼分布範圍東界及日菲繡眼分布範圍西界之間，綠島則被認為是低地繡眼分布的北界。長期的野外觀察紀錄指出東部離島之繡眼鳥形態特徵在島嶼間和與本島間均有差異，為了瞭解臺灣本島與三座東部離島上繡眼鳥的物種歸屬，本研究利用全粒線體基因組、細胞色素c氧化酶（COI）、粒線體細胞色素b（cytb）和還原型菸鹼醯胺腺嘌呤二核苷酸去氫酶（ND2）等基因片段分析其分子親緣關係、生物地理分布及族群遺傳結構，輔以形質測量、體色、鳴叫及歌曲特徵進行綜合分類判斷。研究結果證實該三種繡眼鳥之獨立物種地位，首次確認龜山島應屬於日菲繡眼，綠島的繡眼鳥非低地繡眼而應為日菲繡眼。蘭嶼屬於低地繡眼，臺灣本島則被確認為斯氏繡眼。意即日菲繡眼的分布邊界將延伸至龜山島和綠島與臺灣本島之間；而低地繡眼的分布範圍過去包含菲律賓北部至蘭嶼和綠島，本研究結果更新其北界應南移至綠島與蘭嶼之間。同時，形質測量及歌曲特徵亦能支持分子分析的結果，可做為實地觀察時物種辨認的有效方式。日菲繡眼與低地繡眼均棲息於臺灣東部離島，各自具獨特的族群遺傳和形態特徵，應避免其族群受飼鳥市場交易對其產生獵捕壓力與干擾，將有助於保存遺傳與生物多樣性。

In this study, the integrative taxonomy combining multiple lines of evidence from the analyses based on molecular, morphological, and ecological traits was used to eluciate the taxonomic status of the white-eyes in genus Zosterops in Taiwan. Based on the taxonomic scheme defined by previous studies according to the phylogenetic results and up-to-date information about bird fauna in Taiwan, three currently recognized Zosterops species occur in and around Taiwan. They are Swinhoe's white-eyes (Zosterops simplex), Lowland white-eyes (Zosterops meyeni), and Warbling white-eyes (Zosterops japonicus). However, multiple pieces of evidence are still needed to evaluate their taxonomic status and to further describe their biogeographical distributions. Guishan Island is in the middle of the border of Z. simplex from the west and Z. japonicus from the east, and Green Island was considered the northern edge of Z. meyeni distribution. In this study, the white-eye populations in Taiwan main island and the three east outlying islands were therefore investigated to explore their phylogenetic relationships, biogeographic pattern, and population structure through mitochondrial genome and gene (Cytochrome c oxidase subunit 1 [COI], Cytochrome b [cytb], and NADH dehydrogenase subunit II [ND2]) information. To test the species hypothesis, in addition to the molecular analyses including COI and cytb based species delimitation, the analyses with supplemented data by morphological measurements, body colors, call, and song traits were also conducted. The resulting multiple lines of evidence confirmed the valid species status of the three white-eye species occurring in Taiwan. It is reported for the first time that the white-eye population on Guishan Island should belong to Z. japonicus, and the white eyes on Green Island are Z. japonicus instead of Z. meyeni. The white eyes on Orchid Island should belong to the Z. meyeni. The white eyes occurring on Taiwan main island were confirmed to be the Z. simplex. It meant that the distribution range of Z. japonicus should be extended to the zone covering Guishan Island and Green Island with a boundary located between Taiwan main island and the east outlying islands. The Z. meyeni was previously known to be distributed from the northern Philippines to Green Island and Orchid Island. This study updates its northernmost boundary of the distribution located at the sea between Green Island and Orchid Island. Meanwhile, the molecular species delimitation results corroborated morphological measurements and song characteristics will be applied to species identification in the field. Since both Z. japonicus and Z. meyeni inhabit isolated islands and each of them possesses unique genetic and morphological features, for conservation, it is necessary to prevent them from the threat of the bird trading market for biodiversity preservation.