O. G. Dely szerk.: Vertebrata Hungarica 8/1-2. (Budapest, 1966)
Topál, Gy.: Some observations on the nocturnal activity of bats in Hungary 139-166. o.
tlnu s t as well as CHURCH'S (2) detailed informations on the nocturnal activity of Pipi3trellus pipistrellu s . The American Myotis californicu s and Tadarida mexican a were studied by KRUTZSCH (11,12), and the Indian Piplstrellus mlmu s by PRAKASH (16), for a similar purpose. Finally, laboratory data on the activity of bats and their daily rhythm can be found in the works of GRIFFIN and WELSH (6), KOWALSKI (10), and HERTER (7). In his monography, MÉHELY (13) cites ALTUM's data. And "beyond this, no other references to this interesting problem can be found in our home literature,aside of some handbooks. In the course of my researches on our bat fauna, I had ample occasion to observe also the nocturnal activity of bats. The modest results, in the nature of a preliminary report, are submitted below, mainly to make them available, in view of the almost complete lack of other home data. Methods I observed the- regularities of the movements of bats, emerging to hunt from their daytime shelters - mainly caves or returning to them, but I also list some data when I was able to identify the species flying in the free by bagging some specimens with a shotgun. In all cases, I used direct methods, without recourse to any registering devices or special instruments. Taking up a position in the vicinity of the opening of the bat quarters, the emerging bats can be seen at the time of dusk for a certain period without the use of lamps or other illumination, but later one has to employ a source of light. I attempted tho use of acetylene lamps, but I had to give them up due to their too strong overall light. The light of an electric torch was better, but I found again that, lighting it, the process of emergence came to a sudden
