lo6 The Irish Natttrahst. , ;. October, 



able to add the further fact that we had seen and identified 

 it on the wing, hunting moths, on the stroke of midnight 

 and at 1.30 a.m. Such observations suffice, I think, to 

 show that there is no hour of the night at which Long- 

 eared Bats are not flying and taking prey. To that extent 

 the habits of this species differ radically from those of the 

 Hairy-armed Bat {Nyctalus Leisleri), which retires at the 

 close of the evening twilight to the same sleeping apartment 

 in which it has passed the day, and remains there until 

 the approach of morning, when another brief flight is taken. 

 However, it is one thing to fly at all hours of the night, 

 and another thing to fly continuously throughout the night, 

 as the Pipistrelle or Common Bat {Pipistrellus pipisirellus) 

 seems to me to do, except during those brief intervals of 

 rest which are necessitated by its capture of some insect 

 too large to be comfortably disposed of during flight. From 

 my five summers' observations on the Long-eared Bats in 

 the passage at Ballyhyland, I am now convinced that 

 each individual bat of that species spends a very considerable 

 part of the night at rest — the rests varying in duration 

 from half-an-hour to several hours, and the length of the 

 period of flight being about equally elastic. 



The hours during which the bats were to be seen on the 

 walls of the passage in question varied according to the 

 time of year, and, in some degree, to the state of the 

 weather, the phases of the moon, and other causes too 

 complicated to ascertain. In spring, when the nights 

 were still fairly long, the assemblage would often have 

 reached its largest dimensions by nine or ten in the evening, 

 and have completely dispersed before twelve. In June 

 and July the largest gatherings were generally seen about 

 midnight, or perhaps an hour later. In August the bats 

 again assembled early and broke up before midnight ; 

 but later on — especially after October set in — when the 

 nights grew cold for insect hunting, it was not unusual 

 for the bats to come in early and remain in their cluster 

 the greater part of the night. I did not, however, ascertain 

 at what o'clock on these chilly autumnal mornings they 

 broke up and disappeared. The passage was never used 

 as a sleeping place by day. 



