北臺灣大屯山區洞穴蝙蝠在不同空間尺度下之棲地利用

Abstract

地景往往能形塑物種和生物多樣性的分佈。隨著自然地景迅速轉變為自然特徵和人為特徵混雜的鑲嵌地景，我們迫切需要了解物種對地景變化的反應。蝙蝠是一個分佈廣泛、種類繁多的哺乳動物類群，因此常被視為陸域生態系環境變化的指標物種。本研究檢測北臺灣大屯山區三種常見洞穴蝙蝠(臺灣葉鼻蝠 Hipposideros armiger terasensis、臺灣小蹄鼻蝠 Rhinolophus monoceros、臺灣大蹄鼻蝠 R.formosae)在不同空間尺度(100公尺、250公尺、500公尺)下對森林覆蓋度和邊緣密度的反應；並探討棲所(包含洞穴、廢棄建物)此一小型地景特徵是否與如何影響蝙蝠之棲地利用。在2022年的6月至8月間，我在研究區域架設了125個超音波錄音器，共獲取1,875小時的音頻記錄。結果顯示，臺灣小蹄鼻蝠的活動量和臺灣大蹄鼻蝠的出現機率在所有尺度下皆與森林覆蓋度呈顯著正相關，臺灣葉鼻蝠的活動量在所有尺度與森林覆蓋度無顯著相關；棲所距離與臺灣小蹄鼻蝠與臺灣葉鼻蝠的活動量有顯著負相關，但與臺灣大蹄鼻蝠的出現機率則無相關。然而，這三個物種在所有尺度下皆不受森林邊緣密度的影響。這些研究結果顯示，森林與棲所是北臺灣大屯山區洞穴蝙蝠所需要的兩個重要地景特徵；然而，不同蝙蝠物種對這些地景特徵有不盡相同的反應，因此瞭解個別物種之棲地利用有助我們推估蝙蝠群聚之地景生態。Landscapes shape the distribution of species and biodiversity. With natural landscapes rapidly transforming into mosaics of natural and anthropogenic features, there is an urgent need to understand species responses to these landscape changes. Bats are a widely distributed and diverse group of mammals, often regarded as indicator species for terrestrial ecosystem environmental changes. This study examined the responses of three common cave-roosting bats (Hipposideros armiger, Rhinolophus monoceros, and R. formosae) to forest cover and edge density at different spatial scales (100m, 250m, 500m) in the Datun Mountain area of northern Taiwan. Additionally, I investigated how roosts (including caves and abandoned buildings), as small landscape features, might influence bats’ habitat use. From June to August 2022, I deployed ultrasonic recording devices at 125 sites in the study area, collecting a total of 1,875 hours of audio recordings. The results showed that the activity level of R. monoceros and the occurrence probability of R. formosae were positively correlated with forest cover at all scales. The activity level of H. armiger was not significantly correlated with forest cover at all scales Moreover, the distance of roosts negatively influenced the activity levels of R. monoceros and H. armiger but not influenced the occurrence of R. formosae. However, none of the species responded to edge density at any scale. These findings indicate that forests and roosts are two critical landscape features for cave-roosting bats in the Datun Mountain area of northern Taiwan. Nevertheless, different bat species respond differently to these landscape features, necessitates species-specific approaches to our understanding of the landscape ecology of bat assemblages.