Abstract: An investigation of the seasonal activity of the little house bat, Pipistrellusabramus, in relation to environmental factors particularly temperature and light was made at the suburb of Shanghai.The pipistrelle, a year round resident, forming small colonies in dwellings, began to occur in a very small number at the beginning of March at an outside air temperature not lower than 10-11℃ successively for two evenings generally. The number of bats increased steadily as the weather got warmer and warmer, and as the evening temperature stood above 20℃during May, June and July, the average daily number of a colony of bats appeared to be more or less constant.In August there occurred an abrupt increase of the population size. This was due to young bats which were born in July and were capable of flight and participatod in forage. The bats became less in number in autumn. No bats in foraging could be seen from about the end of November to December and January and February of the following year. Actually there were some individuals which began to stop foraging at the end of September. Thus, it was very likely that there were pipistrellus in torpor and hibernation for a period of more than five months.In March and April, the threshold of the evening temperature for the emergence of a very small number of the bats was 10-11℃, and for most of them, it was 14-15℃. Whereas, in early winter during the first few days of November, the threshold was about 15-16℃ for few individuals of the bats and about 20℃ for more of them. At the middle and the later parts of November the threshold of the evening temperature was about 17-18℃ for the forage activity of very few bats, which was much higher than that in Spring. Thus, obviously, low environment temperature was a conspicuous limit- ing factor to the forage activity of the pipistrelles. The number of the bats emerging from their roost was correlated with the evening ambient temperature, the correlation being very evident: when n = 20 ( 7-26℃ ) , r = 0.9916, df = 18, P<0.01.When the evening temperature was favorable to the bats, light became the main limiting factor to their forage activity. In general, individual pipistrelles began to emerge from the dwelling when the intensity of sky light decreased down to 700 luxes.Most of them left the roost when light was below 500 L, occupying about 63% of 4612 bats observed. and about 13% of the bats emerged at an intensity of light ranging from above 500 to 1000 L. Only a few occured at a much higher intensity up to 25000 L or even higher. Thus, evidently the frequency of the bats leaving the roost was inversely correlated with the intensity of light.By the application of statistics the evening light measured in luxes was divided into 60 groups with Pi as 1 -60, in which 1 =50 luxes.Thus, r=-0.79612, df=59, P<0.05.The correlation was very evident.Light was also concerned with the returning of the bats at daybreak. The number of bats1 flying back to the roost was also inversely correlated with the intensity of light as in the case of emergence for foraging in the evening,except that the majority of the bats returned to the roost at a much lower intensity of light, ranging from 0-50L.Hence. in Summer as the days are long and the nights are short, the emer gence of the bats from the roost being later and their return to the roost earlier than in Spring and Autumn. Moreover, the bats left the roost later on a fine day than on a cloudy day and vice versa on returning to the roost at daybreak.In general, rains interfered with the emergence of the bats.Yet, in fine rains some of the animals might be seen foraging in the sky.With the exception of typhoons, winds showed no affect on the forage of the bats. There was also no influence of the relative humidity of the air as low as 52.5% upon the activity of the pipistrelles.

摘要： 伏翼(Pipistrellus abramus Temminck)为夜行性食虫小蝙蝠类,广布于我国南北和邻近国家,常成小群栖息于城市近郊或小城镇房屋的瓦盖下及屋檐下空隙中。这种蝙蝠在许多地区都有冬眠现象。过去对其季节活动与环境因子关系缺少完整的研究。为此作者于1965—67,1977—79及1981年在上海郊区作了初步观察。结果表明伏翼在不同季节中,其飞出搜食活动具有明显的规律性变化。这种变化同环境因子,特别是温度和光等因子有密切关系。