Abstract: Between May 2014 and May 2015 the evening emergence of the great leaf-nosed bat Hipposideros armiger was studied at a lowland roost in Hong Kong, PRC. Average emergence of H. armiger was 14.6 ± 6.1 min after sunset. There is a strong correlation between first emergence and civil twilight (r = 0.968, P < 0.0001) and also a strong correlation between last emergence and civil twilight (r = 0.977, P< 0.0001). No bat emergence was noted during December and January, the colder months of the year. The species is widely distributed in Asia though little had been published on its basic ecology when compared to bat species in temperate regions. It is hoped that understanding of the seasonal emergence of Hipposideros armiger will help in further investigations of ecology and conservation of this bat species.

Key words: Civil Twilight, Hong Kong, Bat conservation, Great leaf-nosed bat, Emergence time

摘要： 于2014年5月至2015年4月，对香港低海拔栖息地的大蹄蝠夜晚出飞活动时间进行了研究。结果显示大蹄蝠出飞时间平均为日落后（14.6±6.1) min，出飞时间与民用曙暮光呈强正相关（r = 0.968, P < 0.0001），而出飞结束时刻同样与民用曙暮光时间呈现显着相关(r = 0. 977, P < 0. 0001)。。在一年中较冷的12月和1月则没有蝙蝠出飞记录。大蹄蝠虽然在亚洲分布广泛，但是相对于温带地区的蝙蝠物种来说， 关于该物种的基础生态学研究较少。本文对大蹄蝠的季节性出飞行为所开展研究工作，以利有关长远保育的深入研究。

关键词: 民用曙暮光, 香港, 蝙蝠保育, 大蹄蝠, 出飞时间