台灣水鹿（Rusa unicolor swinhoii）歷史分布與豐度

野生動物族群量的多寡可能受諸多因素影響，且為執行保育工作的重要依據。台灣水鹿(Rusa unicolor swinhoii)屬廣適性物種，日據時期分布在低海拔至高海拔的森林中，但由於環境及人為因素的壓力，水鹿分布逐漸退縮至海拔2000公尺以上，各地族群數量也普遍偏低。而在近二十年左右，部分地區的台灣水鹿分布逐漸往較低海拔擴張，且數量有明顯增加的趨勢，但台灣水鹿在全台各地的分布及數量趨勢變化是否一致，目前仍不清楚。本研究整理台灣水鹿的文獻，訪問林務局的山林護管員與原住民部落獵人關於台灣水鹿從1980年至2019年間的分布與相對豐度變化，並探討台灣歷年的保育措施與這些變化是否有關。結果顯示，中央山脈的水鹿狀況在近2000年後變化最為明顯，海拔越高的地區水鹿相對豐度較高，且從保護區往外擴散。雪山山脈的水鹿族群在2010年後才有擴散，但速度較為緩慢，相對豐度偏低，北部區(主要為桃園市、新北市)的水鹿近30年來分布與豐度皆沒有明顯變動。受訪者主觀認為影響台灣水鹿分布與相對豐度變化的原因當中，人為因素影響程度大於自然因素，其中獵人減少是最主要原因。保育政策的實施對於水鹿的族群量恢復有明顯的成效，未來需面對的可能是水鹿數量增加後對生態的衝擊，政府應正視並及早準備。

關鍵字

相對豐度；歷史分布；訪談；鹿

並列摘要

Wildlife population varies with many factors and is the foundation of conservation work. Formosan sambar deer (Rusa unicolor swinhoii) is a eurytopic species. During the Japanese colonization, sambar deer was distributed from low to high-altitude forests. However, due to anthropogenic and environmental factors, distribution of sambar deer was limited to over 2000 m in altitude and population sizes were low in most areas. During the past two decades, the distribution of sambar deer in some areas has expanded to lower altitudes and abundance has increased. Yet the change of distribution and abundance of sambar deer most regions of Taiwan is not clear. This study collated information from literature and interviewed Forestry Bureau patrols and aboriginal hunters to reconstruct the distribution and relative abundance of sambar deer during 1980 and 2019. The relevance between these changes and the conservation policies in Taiwanwas also explored in this study. The results show that the status of sambar deer in the Central Mountain Range has changed most significantly after year 2000. Sambar deer were more abundant at higher altitude and spread out from protected areas. Sambar distribution in the Xue Mountain Range started to expand in 2010 at a relatively lower rate and the abundance was low. The distribution and abundance of sambar deer in the northern districts (mainly Taoyuan City and New Taipei City) has not changed significantly in the past 30 years. Interviewees indicated that among all factors affecting the distribution and abundance of sambar deer in Taiwan, anthropogenic factors had greater impacts than natural causes, with the decrease of hunters being the main factor. The implementation of conservation policy has clear effects on the recovery of sambar population. A possible issue following sambar recovery is its impacts on the ecosystem. The government should prepare for this issue as soon as possible.