摘要
關鍵字：太魯閣國家公園、鳥類、繫放、光度地理定位器、烏頭翁、白頭翁
ㄧ、研究緣起
長期的繫放作業是鳥類研究常被使用的技術。太魯閣國家公園過去已持續進行超過10年的鳥類繫放，累積了超過100種、10000隻鳥類的繫放紀錄，並增加了數十種國家公園的新紀錄鳥種。定期的紀錄繫放可以用來評估鳥類在繫放地點的數量變化情況。由繫放—回收紀錄可知許多在園區度冬的候鳥每年都會重複回到園區同一地點度冬。限於他們的體型，過去對於這些鳥類的遷移路徑極難掌握。本研究持續在太魯閣地區進行鳥類繫放，使用歷年累積的繫放成果，探討各鳥種的季節性移動現象，以及降遷個體的性別差異；追蹤園區內小型候鳥的遷移路徑；並進行園區內烏頭翁、白頭翁和雜交個體的數量調查。
二、研究方法極過程
鳥類繫放
在太魯閣國家公園內的洛韶和合歡農場等地進行鳥類繫放。主要繫放種類為小型鳥類。繫放以霧網捕捉，捕捉到的個體分別記錄捕獲日期和地點，並在跗蹠骨套上有編號的金屬環、測量各項形值測量、自腋下靜脈採集約20 ul的血液等。完成操作的個體立即於原地野放。
留鳥在繫放地點的季節性移動
從繫放作業持續年份較久的高海拔合歡農場和中海拔洛韶二地的繫放紀錄中，各找出繫放數量較多的10種鳥，分析這些鳥種的數量在樣區的季節性變動，以推估降遷行為。此外，利用分子性別鑑定確認繫放個體的性別，從不同季節族群性別比例的變化，探討留鳥降遷策略。
黑臉鵐遷移路徑追蹤
在第一年冬季的繫放業中所捕獲的臉鵐身上綁上光度地理定位器，追蹤黑臉鵐的遷移路徑和繁殖地。待第二年冬季回收標誌的個體，回收定位器以讀取光度記錄，轉換為經緯度座標。
太魯閣地區烏頭翁、白頭翁和雜交個體的數量調查
於太魯閣國家公園內及周邊地區進行調查，紀錄觀察到的烏頭翁、白頭翁、雜交白型和雜交烏型的出現數量，確認四種型態個體在園區內的分布現況，並與過去國家公園的調查結果相比，以瞭解太魯閣周邊地區烏、白頭翁雜交現象的變化。
三、重要發現
鳥類繫放
計畫期間共完成33趟次鳥類繫放作業，一共捕捉到64種、1891隻鳥，其中1419隻新增上環的個體。連同繫放期間的觀察，一共紀錄到126種鳥類。與歷年繫放的成果相比，洛韶樣區冬候鳥的種類和多樣性，都有顯著減少的現象。
留鳥在繫放地點的季節性移動
由各種鳥繫放數量的變動，可大致看出他們在樣區中的居留狀況：在洛韶樣區，斯氏繡眼（綠繡眼）在冬季完全消失，冠羽畫眉、黃胸藪眉（藪鳥）和繡眼畫眉在冬季的數量較夏季多；而粉紅鸚嘴、山紅頭、小鶯等在各月份都有穩定記錄，數量沒有明顯的季節波動。在合歡農場樣區，深山鶯、冠羽畫眉、黃胸藪眉、栗背林鴝等在夏季的數量多於冬季的數量，而白眉林鴝和火冠戴菊鳥則是相反：冬季的數量多於夏季的數量。褐頭花翼、紅頭山雀、台灣朱雀（酒紅朱雀）和山紅頭等鳥類的數量在冬季和夏季沒有明顯的波動。比較在二樣區都有較多繫放數量的鳥種，發現冠羽畫眉和黃胸藪眉有明顯的降遷現象：夏季在高海拔的合歡農場數量較多，海拔較低的洛韶則是冬季數量較多。
不降遷的山紅頭和褐頭花翼在夏季與冬季沒有明顯的數量變化，且雌鳥和雄鳥的比例在冬季和夏季也沒有明顯的差異。而白眉林鴝、栗背林鴝、黃胸藪眉、冠羽畫眉、紅頭山雀、臺灣朱雀和深山鶯等降遷鳥種的性別比例都是冬季的雌鳥比例低於夏季的雌鳥比例。
黑臉鵐遷移路徑追蹤
一共於第一年度冬季，在洛韶樣區的52隻黑臉鵐身上安裝光度地理定位器，這些個體包含黑臉鵐的3個亞種，且每個亞種都包含雄鳥及雌鳥。由於黑臉鵐的南遷時程較晚，直到2021年11月的繫放調查才開始捕捉到黑臉鵐，並且回收到一隻在2021年3月被綁定光度地理定位器的黑臉鵐。根據期間的光度紀錄資料，轉換成座標估計值，發現該個體春季北返的遷移路線採用較偏西的內陸路，秋季遷移則較偏東邊的跳島海線。春季北返時段約為5月中至6月初，秋季南遷時段約為9月中至10月中；6月中至9月初穩定停留在俄羅斯東岸的阿默爾地區度夏（繁殖地）。
太魯閣地區烏頭翁、白頭翁和雜交個體的數量調查
不論是太魯閣峽谷地區、立霧溪以南和蘇花公路南段的調查結果，都顯示與1991年的調查結果相比，二次調查各外型鳥的比例有明顯變化。在峽谷地區，烏頭翁和白頭翁的比例變化不大，但雜交白型個體所佔的比例大幅減少，雜交烏型的比例則增加。台九線調查點雜交烏型和雜交白型個體所佔的比例大幅減少，烏頭翁的比例則大幅增加。蘇花公路的調查部分顯示烏型個體所佔的比例大幅增加。
四、主要建議事項
根據本年度研究成果及研究過程中的發現和心得，提出以下建議：
建議一
持續進行太魯閣地區的鳥類繫放作業
立即可行建議
主辦機關：太魯閣國家公園管理處
協辦機關：各鳥類繫放單位
建議二
關注太魯閣地區候鳥群聚的變化：立即可行建議
主辦機關：太魯閣國家公園管理處
協辦機關：無
建議三
持續追蹤太魯閣及周邊地區烏頭翁、白頭翁和雜交個體數量的變化：立即可行建議
主辦機關：太魯閣國家公園管理處
協辦機關：無
Abstract
Keywords: Bird, Birds Banding, Geolocator, Hybridization, Taroko National Park
Bird banding is a widely used technique in avian research. In Taroko National Park, a long-term bird banding program has been conducted for more than ten years. More than 100 species have been banded, dozens of them are new records to the Park. The banding records can be used to evaluate seasonal movement pattern of birds. Through bird banding, we found that many migratory species showed high fidelity for their wintering sites. In this study, we continued bird banding in Taroko National Park and analyzing seasonal movement of birds. In addition, we used geolocators to reveal the migration and breeding sites of Black-faced Bunting. We also conducted field survey to recorded the number of Styan's Bulbul, Light-vented Bulbul and their hybrids.
The bird banding program captured 64 bird species with a total of 1897 individuals. Among them, 1425 were new banded, the others are recaptures. Combined with observation and banding data, 126 species were recorded. From the banding data, we found a significant reduction in the species abundance and diversity of wintering bird.
For resident species, in mid-elevation Loushao (洛韶) banding site, Swinhoe's White-eye disappeared completely in winter months. In contrast, Taiwan Yuhina, Steere's Liocichla and Morrison's Fulvetta were more abundant in winter than in summer, while Vinous-throated Parrotbill, Rufous-capped Babbler, Brownish-flanked Bush Warbler were relative stable in numbers among months. in high-elevation Hehuan farm (合歡農場) banding site, Yellowish-bellied Bush Warbler, Taiwan Yuhina, Steere's Liocichla, Collared Bush-Robin were more abundant in summer than in winter, while White-browed Bush-Robin and Flamecrest showed a different pattern, they were more abundant in winter than in summer.
Rufous-capped Babbler and Taiwan Fulvetta are species without altitudinal migration, the sex ratio (female: male) of winter and summer population were similar. However, the seven altitudinal migration species (White-browed Bush-Robin, Collared Bush-Robin, Steere's Liocichla, Taiwan Yuhina, Black-throated Tit, Taiwan Rosefinch and Yellowish-bellied Bush Warbler) showed the same pattern: the sex ratio were lower in winter, indicating more female left the banding site in winter.
Fifty-two Black-faced Buntings were mounted with geolocators, including all the three subspecies. At present, only one bird was recaptured. From the light level data, we found the bird summering at Amur region, eastern Russia. The spring migration was from mid-May to early June and autumn migration was from mid-September to mid-October.
For the survey of Styan's Bulbul, Light-vented Bulbul and their hybrids, compared with the records conducted in 1991, we found that their relative ratio has changed significantly. In the Taroko Gorge area, the percentage of white-headed morph hybrids reduced greatly while the percentage of black-headed morph hybrids increase greatly. In the south of Taroko Gorge, the percentage of both black and white-headed morph hybrids decreased while the percentage of Styan's Bulbul increased. In the north of Taroko Gorge, the percentage of black-headed individuals (including Styan's Bulbul and black-headed morph hybrids) increased greatly.