LEISLER'S BAT 93 



had homed respectively 33, 30, 24, and 23 minutes before 

 sunrise.^ 



" The hole into which three of the four bats had vanished 

 was evidently the entrance to a cavity of some extent, but it 

 was too narrow to admit of any examination of the interior. 

 In the evening I saw the three come out again, one at 7.53 and 

 two at 8 P.M., or 16 and 23 minutes after sunset. On the 

 following evening five were seen, all issuing from the same 

 hole, between 7.47 and 7.57 — their times of emergence being 

 respectively 12, 16, 17, 19, and 22 minutes after sunset. On 

 the 1 2th I again saw five come out: the first one minute, the 

 others respectively 8, 11, 13, and 16 minutes after sunset. 

 When quitting their abode, though high fliers at other times, 

 these Bats skim very low over the grass. 



" The question of the animal's return to its sleeping-den 

 during the night was less easily settled. On two evenings I 

 watched the hole without any success, though the moon was 

 full and bright, and I hid in the shadow of the ash-boughs not 

 to disconcert the homing bats. The fact, however, that this 

 large and noisy species suddenly ceases to be either visible or 

 audible about an hour and twenty minutes after sunset weighed 

 strongly against the idea of its continuing on the wing all 

 night. Other considerations also pointed to the probability of 

 its retiring early, as the Noctule is known to do. . . . Dr Alcock 

 had drawn my attention to the fact that Hairy-armed Bats 

 shot by him an hour after sunset had their stomachs so 

 crammed with food that it seemed a physical impossibility 

 they could feed much longer. 



" I therefore argued that since I could not detect the bats 

 going in in the evening, I must endeavour to catch them as 

 they came out in the morning. This would at least prove the 

 fact, though not the time, of their retirement after dusk. So, 

 on the night of August 12th, I fixed a net at midnight over the 

 mouth of the hole. In the early morning hours of the 13th 

 I watched by this net . . . and at 3.15 a.m. heard a Bat gently 

 flop into it. I found that I had secured a fine female . . . 



' " In explanation of these figures, I should state that at Ballyhyland (lat. 52° 31' N., 

 long. 6° 43' W.) sunrise on August loth is 4 minutes later than at Dublin, and 

 sunset I minute earlier.'' 



K 2 



