379 



THE FLIGHT OF BATS. 



ARTHUR WHITAKER, 



Worsbrough Bridge. 



{Continued froiii page JS3-) 



The Pipistrelle Bat {Pipistrellus pipistrellus) usually appears 

 about thirty to forty minutes after sunset. It is probably our 

 commonest Yorkshire bat. Its flig'ht is unsteady, erratic, and 

 fluttering^, its size small, the wing" expanse being- usually under 

 eig^ht inches. It flies g^enerally at a low altitude, seven to twelve 

 or fifteen feet, and usually selects a short beat up and down, 

 which it keeps, fluttering with great persistency. This beat 

 varies in length from a dozen yards, merely the length of a barn 

 side or the hedge of a small garden, to several hundred yards, 

 the round of a large plantation or small wood. One thing can 

 almost always be relied on however, and is remarked on by 

 J. G. Millais (' Mammals of Great Britain and Ireland '), ' If the 

 bat is observed to pass a particular spot, it may be expected 

 there again in a few seconds' or a few minutes' time ' (according 

 to the length of its round or beat). If struck at when flying, 

 with stick, umbrella, or other implement, as its low flight often 

 tempts people to do, it surprises its assailant by wheeling round 

 several times, often within a few feet of him. I find this species 

 the easiest to net of any, and I have obtained very many scores 

 of individuals at different times, either in my ordinary gauze 

 butterfly net, or still more effective fisherman's landing-net. In 

 early spring and late autumn this bat not infrequently flies 

 during the daytime, especially when a succession of cold nights 

 prevent any insects from stirring, while at the same time the 

 days are so warm as to arouse the bats from their proper winter 

 torpor and thus make them feel the need of food, and at leng-th 

 drive them forth in the sunshine to prey upon the few insects 

 which the noonday warmth has also induced to fly. When flying 

 in the daytime, I have most commonly seen it flitting high up 

 about the tree tops. 



The Pipistrelle flies regularly on favourable nights from 

 March to the end of November, and even during the remaining^ 

 months an exceptionally mild evening will not infrequently 

 tempt it out, so that it may occasionally be seen on the wing 

 even during December, January, or February. 



It is almost ubiquitous, and most catholic in its choice of a 

 hunting-ground. I have seen it in the most secluded glades of 



iyo6 November i. 



