THE NOCTULE, OR GREAT BAT 73 



by the beating of their wings, but even on moonlight nights 

 all that one sees is a form silhouetted for an instant against 

 a patch of sky. When the Bat is flying against a background 

 of tree-trunks or foliage, one can see nothing. It is true that 

 a faint rustle may be heard when a Bat actually enters the 

 hole, but this resembles the noise made when it pitches for an 

 instant on the tree-trunk ; and if two or more Bats arrive to- 

 gether, as often happens, the confusion is increased. A good 

 deal of intermittent squeaking may be heard in the den after 

 the arrival of the second Bat." 



In the paper above referred to, Mr Oldham, judging from 

 the habits and demeanour of captive specimens, expressed 

 the opinion that the period of activity is limited to the 

 short vespertinal flight, and that it does not again leave its den 

 before the following evening. Mr Steele Elliott, dissenting from 

 this view,^ mentioned two instances of matutinal flight which 

 happened to come under his notice ; and later Mr C. B. Moffat, 

 from the analogy of the closely allied Leisler's Bat, as well as 

 from his own slight experience of the present species, argued ^ 

 that there must be two flights each night. Mr Oldham sub- 

 sequently undertook an all-night watch* outside a Noctule 

 den in Cheshire on 20th May, with the result that the 

 occurrence of a matutinal flight in this species may now 

 be regarded as beyond question, although it is possible that 

 fewer individuals are abroad at dawn than in the evening 

 twilight. Mr Oldham found that no bat entered or left the 

 hole after 9.36 p.m., but that there was intermittent squeaking 

 until ten o'clock, and "a slight squeaking in the den at long 

 intervals until 2,40 (eighty-five minutes before sunrise), when 

 the noise increased, and more than one bat emerged — in the 

 gloom I could not tell the exact number — and all was still 

 until 3.20 (forty-five minutes before sunrise), when three 

 returned. These dashed round among the branches, alighting 

 on the trunk at the mouth of the hole once or twice, and then 

 dashing away again before entering the den, as Noctules 

 generally do on returning from the vespertinal flight. There 

 was no squeaking after the Bats entered the den, and I heard 

 none until 4.2, when I left the tree." 



1 Zoologist, 1901, 153. 2 Irish Naturalist, 1905, 105-106. ' Zoologist, 1905, 307. 



