台灣長尾麝鼩(鼩形目：尖鼠科)棲地利用之研究

Abstract

在國內各地的資源調查中，中低海拔地區多種棲地內能捕獲到的鼩形目動物以台灣長尾麝鼩最為優勢。本實驗希望藉由探討台灣長尾麝鼩在不同巨棲地內的微棲地利用模式，來檢視其是否屬於廣泛利用棲地的物種，以及該種是否偏好使用各巨棲地共通的微棲地因子，或是可因應巨棲地內各因子的可獲得性而調整棲地利用模式。實驗於2004年4月至2005年6月間，在新竹白蘭地區選擇四種不同類型的巨棲地，於乾濕兩季，每月以掉落式陷阱及改良式薛門氏陷阱，進行台灣長尾麝鼩的捕捉，並在四類巨棲地內進行微棲地調查，以比較巨棲地間、以及巨棲地內各捕捉點的微棲地因子差異。 實驗結果發現台灣長尾麝鼩在闊葉林、針葉林、竹林、果園四種類型的巨棲地內皆會出現，但其最偏好利用具有較多倒木、倒木覆蓋度較高的針葉林，較排斥利用有過多岩石及地表較為裸露的闊葉林。而在巨棲地內的分析則發現，台灣長尾麝鼩在不同類型的巨棲地內，會偏好利用幾項共通的微棲地因子，包含了較多倒木所產生的整體效應，以及較高的地上層覆蓋度和落葉覆蓋度；但是，台灣長尾麝鼩也會因應不同巨棲地內各微棲地因子的可獲得性，來調整其利用比例。顯示台灣長尾麝鼩確實能廣泛分佈於中海拔的各類型巨棲地內，並能有效的利用巨棲地內各種環境資源，但各巨棲地內台灣長尾麝鼩數量的多寡仍會受到其偏好因子多寡之影響。

Previous surveys of terrestrial fauna showed that Crocidura tadae kurodai is the most common soricomorpha species found in many types of habitat at mid to low elevation in Taiwan. In this study, we investigated patterns of microhabitat use by C. tadae in four different macrohabitat types to test the hypotheses wheather C. tadae is a habitat generalist or not. If it was a habitat generalist, does C. tadae prefer to use some microhabitat factors which are commonly found in all macrohabitat types, or does it adjust the use of different microhabitat factors according to their availability in each macrohabitat types. Between April 2004 and June 2005, we trapped C. tadae monthly during wet and dry season by pitfall traps and modified Sherman’s traps in four macrohabitat types in Bailan, Hsinchu. In addition, we measured the microhabitat factors in all macrohabitat types, to compare the differences of microhabitat at each trap site within and between macrohabitat types. Our results revealed that C. tadae could be captured in board-leaved forest, conifer forest, bamboo forest and orchard, but it preferred conifer forest which has more fallen logs and higher coverage of fallen logs, and avoided board-leaved forest which has more rocks and exposure surface. Within each macrohabitat type, C. tadae preferred some microhabitat factors commonly found in different macrohabitat types, including whole effects of fallen logs, higher coverage of understory and litter layer. However, C. tadae also can adjust its microhabitat use based on the availability of each microhabitat factor. Our study revealed that C. tadae could use many environment resources efficiently within each macrohabitat, and distribute in many macrohabitat types at mid to low elevation, but the abundance of C. tadae in each macrohabitat type was affected by the availability of its preferred microhabitat factors.