以領域描圖法研究梅峰地區繁殖鳥類密度

Abstract

領域描圖法被視為能提供準確的鳥類密度估計，除了提供詳細、可靠的資料，並適合於探討繁殖鳥類與棲地間的細微關聯。本研究於民國94年三月上旬至七月下旬對台大梅峰山地農場約40公頃範圍之鳥類群聚，進行連續20週、共40天次之領域描圖法。研究目的為建立台灣地區中海拔繁殖鳥類群聚之領域描圖法操作方法及分析研究區域之鳥類群聚組成。研究期間紀錄到57種鳥共5719筆紀錄，其中29種為研究區域內留鳥，4種為研究區域之夏候鳥，而16種有明顯於研究區域內繁殖之證據。在扣除不合適計算領域之鳥種後，共有21種鳥可繪出其領域分布，其中以藪鳥(Liocichla steerii) (73個領域)、冠羽畫眉(Yuhina brunneiceps) (35個領域)、白尾鴝(Cinclidium leucurum) (29個領域)、白耳畫眉(Heterophasia auricularis) (23個領域)、小鶯(Cettia fortipes) (21個領域)、山紅頭(Stachyris ruficeps) (17個領域)、竹雞(Bambusicola thoracica) (15個領域)最具優勢。研究結果顯示，以領域描圖法調查台灣中海拔當地繁殖鳥類群聚，最佳時間為四月上旬至六月上旬。此外，在進行領域描圖法時伴隨錄音回播，以每種鳥類的領域性鳴唱聲重複兩次的方式，對於所調查到之鳥類種數及數量並無顯著影響。另一方面，研究區域內任一點至道路系統之距離在40公尺內，對大部分的鳥種皆能有效覺察。根據本研究之結果，我認為領域描圖法適合用於調查台灣中海拔鳥類群聚。

Territory mapping has been viewed as the most accurate method to estimate avian abundance and density. It provides detailed, unbiased data for ecological research and is suitable to study the relationships between breeding birds and their habitats. I conducted territory mappings in an area of around 40 ha in Meifeng Highlands Experiment Farm of National Taiwan University for a period of consecutive 20 weeks, 40 census days in total, from early-March to late-July, 2005. The objectives of this study were to establish field protocols of territory mapping that are suitable for terrestrial breeding bird communities in mid-elevation of Taiwan and to analyze bird community composition of the study site. Fifty-seven bird species from 5719 registrations were recorded during the 40 field censuses. Among them, 29 species were local residents and 4 were summer breeding species of the study site. Sixteen species had definite evidences to breed at the study site. After eliminating species that were unsuitable for territory mapping, territories of 21 species were compartmentalized. Steere's Liocichla (Liocichla steerii) (73 territories), Formosan Yuhina (Yuhina brunneiceps) (35 territories), White-tailed Blue Robin (Cinclidium leucurum) (29 territories), Taiwan Sibia (Heterophasia auricularis) (23 territories), Strong-footed Bush Warbler (Cettia fortipes) (21 territories), Red-headed Tree Babbler (Stachyris ruficeps) (17 territories) and Chinese Bamboo Partridge (Bambusicola thoracica) (15 territories) were the dominant bird species in the study site. The results suggest that the optimal period for territory mapping in the study site is from early-April to early-June since this period contained the highest registrations recorded and all local breeding species. In addition, repeatedly playing two repetitions of identical syllables of each species’ territorial song did not have any significant effect on total number of species and total number of registrations recorded on each day. On the other hand, every point in the study site was within 40 m to the census route and most bird species can be well detected at this distance. In general, I consider that territory mapping is a suitable method to census bird community at mid-elevated of Taiwan.