92 VESPERTILIONID^— NYCTALUS 



time of flight ; for I have never seen it when the day's viaxiinum 

 was below 52|-°, and never nuiiieroiisly with a lower maximum 

 than 56° Fahr." 



In 1899 Dr Alcock^ stated his belief that the activity of 

 Leisler's Bat is probably restricted to a single hour's flight each 

 evening, commencing about fifteen minutes after sunset, ten 

 minutes earlier in spring, and ten minutes later in autumn. 

 The history of the discovery of the exact limits of this 

 vespertinal, together with the existence of a matutinal flight 

 as well, is so peculiarly Mr Moffat's own, that I feel that I 

 should be doing him an injustice did I not quote his description 

 at full length. 



" For a mammal to enjoy so short a period of daily activity 

 as this one hour," wrote Mr Moffat in 1900, "would be very 

 singular, and during a recent visit to Fassaroe [Co. Wicklow] 

 . . . I obtained evidence that the flight is not so strictly 

 limited, for on July 22nd I saw several bats of this species flying 

 in the early morning : — the first and last being noted respec- 

 tively at 2.56 and 3.36 a.m., or 65 and 25 minutes before 

 sunrise. That they were Hairy-armed Bats I was certain ; 

 but specimens could not then be procured." 



However, the discovery that Leisler's Bat " is a morning 

 flier was a useful step towards tracing some of these animals 

 to their sleeping - place at Ballyhyland, the morning light 

 being infinitely preferable to that of evening for such a 

 purpose. On the morning of August loth I accordingly 

 watched from 2.45 a.m. in the pasture-field already referred to, 

 taking my stand near an old and hollow ash-tree which I had 

 reason to suspect the bats might inhabit. At 3.35 a.m. their 

 screams were audible in the open, where several were soon 

 afterwards seen, hawking and sporting above the level of the 

 tree-tops. At 4.2 one of them suddenly dipped from its eleva- 

 tion, and when near the ground darted towards the trunk of the 

 old ash, where it entered a hole about seven feet from the 

 ground. At 4.5 another dipped, and shot into the same hole. 

 At 4. 1 1 a third followed suit ; at 4. 12 a fourth entered another 

 hole, some two feet higher up in the same tree. This was 

 the last bat seen that morning. The four individuals noted 



^ Irish Naturalist^ 1899, 169-174, and map. 



