Isaac S Suthakar, Marimuthu G
Department of Animal Behaviour and physiology, School of Biological Sciences, Madurai Kamaraj University, 625 021, Madurai, India.
Oecologia. 1993 Dec;96(3):426-430. doi: 10.1007/BF00317515.
The outflying and homeflying activity pattern of a colony of the Indian pygmy bat Pipistrellus mimus occupying a tunnel was studied under natural conditions. Before leaving the tunnel for foraging, the bats made circling flights outside to sample the environmental light conditions. The onset and end of activity was related to the times of sunset and sunrise respectively. The onset of flight during evening commenced after sunset from mid-September to mid-April, before sunset during the rest of the year. Onset of activity occurred at higher light intensities compared to light intensities prevailing during the return flight to the roost in the morning. The duration of activity time showed a curvilinear relationship with the duration of the night. The phase relationship between onset and end of activity, and sunset and sunrise, showed marked seasonal variations in the values of Ψ, Ψ, and Ψ. However, such changes in the phase angle properties did not obey Aschoff's seasonal rule. Based upon the data obtained on the onset and end of activity patterns for five species of bats, including the data from this study, we report that P. mimus is the earliest to set out for foraging in the evening and among the last to return home in the morning. This might be due to dusk and dawn peaks in activity of the prey insects.
在自然条件下，对占据一条隧道的印度侏蝠（Pipistrellus mimus）群体的外出飞行和归巢飞行活动模式进行了研究。在离开隧道觅食之前，蝙蝠会在外面绕圈飞行，以采样环境光照条件。活动的开始和结束分别与日落和日出时间相关。9月中旬至4月中旬，傍晚飞行的开始在日落后，一年中的其他时间则在日落前。与早晨返回栖息地的飞行期间的光照强度相比，活动开始时的光照强度更高。活动时间的持续时间与夜晚的持续时间呈曲线关系。活动开始和结束与日落和日出之间的相位关系在Ψ、Ψ和Ψ值上表现出明显的季节性变化。然而，相位角特性的这种变化并不遵循阿绍夫季节性规则。根据包括本研究数据在内的五种蝙蝠活动模式开始和结束的相关数据，我们报告称，侏蝠是傍晚最早出发觅食且早晨最晚回家的。这可能是由于猎物昆虫在黄昏和黎明时的活动高峰所致。
