LEISLER'S BAT 95 



earliest and latest instances having been ^^ and 21 minutes 

 before the sun. It has been shown that the duration of one 

 individual's (evening) flight was at least 7 1 minutes, whilst that 

 of another's (morning flight) was not more than 65 minutes. 

 The usual duration is, in all probability, not far from the mean 

 between these two figures. The animal, therefore, in summer, 

 spends one-tenth of its time on the wing, and the remaining 

 nine- tenths in its sleeping-hole. In the shortness of its flight- 

 time it is probably unique among Irish bats." 



In its hibernation this species appears to differ from the 

 Noctule in that, instead of collecting in numbers for the 

 winter sleep, the slight evidence which we possess seems to 

 indicate that it scatters and hibernates singly. Mr Moffat, 

 watching the daily flight of the bats in September, found that 

 early in the month they deserted their summer quarters and 

 bestowed themselves in separate crevices in the higher parts of 

 the same tree. They migrated singly on different dates. " On 

 Sept. loth three (instead of four) emerged from the common 

 den; on the nth, two; on the 13th, none. This shows that 

 they changed their abode voluntarily ; if they had been 

 disturbed or alarmed, they would all have left at once. They 

 still fly every evening from their new quarters. No two inhabit 

 the same hole," a description borne out by Mr Finn's solitary 

 Carlow individual, then probably in its winter quarters. 



The flight of Leisler's Bat resembles that of the Noctule, 

 but, as stated above, Tomes believed it to be a little less 

 regular in its haunts and less definite in its area of flight than 

 the larger species ; and in Wexford, where I have seen it flying 

 at a considerable elevation, I cannot be sure of finding it in any 

 particular spot. Further, the colony in the stable wall resented 

 disturbance, and has departed. Mr Moffat, however, informs 

 me that in localities where it is abundant, as at Enniskerry in 

 Wicklow, it may be observed evening after evening in fairly 

 numerous groups. 



At his own home at Ballyhyland, Wexford, the bats on 

 emerging from their den go off almost invariably in the same 

 direction. He found when he intercepted their line of flight that 

 they passed certain points more than a quarter of a mile away 

 with great regularity, still dashing along as if bound for a fixed 



