240 The Irish Nahiralist. [October, 



The pedestrian habits of this species in captivity (so unlike 

 those of the Pipistrelle) have been noticed by Dr. Alcock 

 (/. N'at., vol. viii., p. 173), and by Mr. Barrett-Hamilton (/. Nat.^ 

 vol. ix., p. 134). Those of my specimen were .similar ; I onl^^ 

 once saw it take flight, from the edge of my bed, and I 

 suspect til at Vcspcrugo Leisleri has some difficulty in taking 

 wing from a level .surface. Once, too, I was wakened by the 

 whirr of its wings cutting circles round the room. 



This bat is undoubtedly an early hibernator, retiring 

 abruptly about the 26th of September, the date mentioned in 

 Dr. Alcock's paper. The exact period is probably fixed by 

 the falling temperature. At Ballyhyland, in 1899, my obser- 

 vations in the accustomed place of flight were — September 

 25th, usual number flj^ng ; 26th, onl}- one ; 27th, none. The 

 maximum temperatures for the above three dates were 

 respectively 57^^, 53^, and 49*^ Fahr. 



But though hibernation thus commences early, it is subject, 

 like that of other species, to interruption on the return of 

 warm weather. Near Fassaroe, during a warm spell, I have 

 seen I^eisler's Bat flying numerously on October 17th, and a 

 single specimen on October 20th. The late A. G. More 

 identified one captured indoors at Cromlyn as late as November 

 1 6th, 1894 {Irish Naturalist, 1897, p. 135), and Mr. Nichols has 

 informed me that this specimen is in the Museum. The 

 lowest temperature at which I have noted Hairy-armed Bats 

 in the open is 46° (on October 8th, 1899), but on that evening 

 they were out in some numbers. I therefore think that this 

 species is more influenced by the heat of the day than by 

 that of the actual time of flight ; for I have never seen it when 

 the day's viaximuvi was below 52^'-', and never numerously with 

 a lower maximum than 56® Fahr. 



A slight odour, not unlike the '* scent" of the fox, marks the 

 entrance to the den of the Hairy-armed Bat. 



Ballyhyland, Co. Wexford. 



