台灣中部摺翅蝠的棲地利用與其生活週期及外寄生蝠蠅感染之關係

Changes in Habitat Utilization of the Japanese Long-Winged Bat Miniopterus schreibersii in Association with Its Life Cycle and Batfly Infection in the Central Taiwan

本研究於2007年9月至2008年8月間觀察記錄棲息於南投縣地利一處引水涵洞的摺翅蝠（Miniopterus schreibersii）群集對棲所一整年的利用狀況，同時檢視該摺翅蝠群集所感染的外寄生蝠蠅的數量變化，以及蝠蠅在各月份對於宿主性別的選擇及生殖季節對懷孕個體偏好的差異。結果顯示，雄蝠在9-11月出現睪丸腫大之產精現象，雌蝠在5月出現明顯懷孕現象，但該摺翅蝠群集只利用此涵洞爲夏棲所（summer roost），並不利用作爲生殖育幼及度冬處所（hibernacula），且在蝠蠅數量高峰期間，摺翅蝠群集出現遷徙的現象。以整個蝙蝠群集而言，每月蝠蠅的感染數皆以短鋏蛛蠅爲最高，姜宜蛛蠅爲最低。短鋏蛛蠅與長鋏蛛蠅的感染高峰值出現在2008年6月，姜宜蛛蠅的感染高峰值出現在2007年9月，3物種的感染豐度（abundance）最低值皆出現在2008年1月。雌、雄蝠感染短鋏蛛蠅的數量在2007年10月及2008年1月出現差異（10月雄蝠＞雌蝠；1月雌蝠＞雄蝠），而感染長鋏蛛蠅的數量在2008年5月出現差異（雄蝠＞雌蝠），至於感染姜宜蛛蠅的數量則分別在2008年3月及5月出現差異（3月雌蝠＞雄蝠；5月雄蝠＞雌蝠）。懷孕雌蝠感染短鋏蛛蠅的數量明顯的高於未懷孕的雌蝠個體。這現象顯示了該種蛛蠅可能傾向於寄生在有利於垂直感染（即由母體直接感染幼體）或免疫力較低的懷孕宿主個體上。

In this study we investigated monthly changes in habitat utilization of the Japanese long-winged bat (Miniopterus schreibersii) colony in a culvert situated in Dili, Nantou County, September 2007 to August 2008. We also examined the species composition and abundance of its parasitic batflies, their preference to sexes and pregnancy of the host bats. The results showed that male bats with significant sperm production were observed from September to November and female bats were pregnant in May. The culvert served as their summer rooster; it was not used as a place for breeding and hibernacula. Nycteribia parvula was the most heavily infected batfly, while Penicillidia jenynsii was the least infected fly. The peak infection of the two species of the flies, N. parvula and N. allotopa mikado, was found in June, 2008, while the peak of the P. jenynsii was in September, 2007. The lowest infection of the above three flies was in January 2008. There were sexual differences of the host bats in the infection of N. allotopa mikado in May 2007, the infection of P. jenynsii in March and May, and the infection of N. parvula between July 2007 and January 2008. The number of pregnant females infected by N. parvula was significantly higher than that of non-pregnant females, suggesting that N. parvula inclined to infect pregnant females because they served as favorite hosts for vertical infection from mother bats to juvenile bats or they had a vulnerable immune system against the fly.