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.

2028 on 11 June, 1964, in Németbánya, that is, 45, respectively 47, minutes after sunset. I have collected Nyctalus leisler

i, in a calm, slightly cloudy day, at 1837 on 2 April, 1964, that is, 22 minutes after sunset, in Deszkáspuszta. In Kisszépalma-puszta, the first specimens appeared uniformly at 1930, on 26 May, 1965 (sky overcast

,weather mild), and 30 May,

1965 (weather clear, cold), 3 minutes, respectively 1 minute, after sunset. My single record of Myotis emarginatu

s refers to a specimen leaving the Pisznice Cave at 2025 on 19 June, 1957. This vould imply that its activity starts sooner than that of Myotis myoti

s. Summary Surveying our results, we can state that, on the same date and locality of observation, Rhinolophus euryal

e, then Miniopterus schreibers

i, finally Myotis myoti

s departed for their nocturnal flight after sunset, and returned in a reverse order to their daytime shelter.This is substantiated primarily by the data collected at the Pisznice Cave. Since the nocturnal activity of the examined species obviously follows the seasonal changes of the movement of the sun, it also follows that the period of their stay in the free prolongs with the lengthening nights. Differences were found between the behaviour after dusk of the Rhinolophus euryal

e populations in the Pisznice and Baradla Caves, not to be interpreted on the basis of the available data. In the case of Myotis myoti

s, there was also a difference between the nocturnal activity of the Pisznice and Héviz populations, but here the cause may lie in the stimulating earlier flight of Rhinolophus euryal

e on the other bat