114 VESPERTILIONID^— PIPISTRELLUS 



More recently, Mr C. B. Moffat ^ has taken the trouble to 

 compare the movements of bats, hedgehogs, and frogs from 

 26th October 1901 to 21st February 1902, as observed 

 at Ballyhyland, County Wexford, Ireland. His facts are 

 carefully tabulated, and mark a distinct advance in our know- 

 ledge of the winter routine of three very different types of 

 animals. He finds that bats (and he thinks that practically 

 in every case they were Pipistrelles) "were observed on nine- 

 teen evenings in November, nine evenings in December, ten 

 evenings in January, and five evenings in February." He 

 therefore concludes that at "all times during the winter, pro- 

 vided the temperature of the hour of dusk is above 43° Fahren- 

 heit, some Bats of the common species are pretty sure to be 

 found flying, if looked for in suitable localities. Below 43° 

 their emergence is not to be calculated on, but it sometimes 

 takes place at lower temperatures, down to 39°.^ It will be 

 noticed that a return of mild weather brings out the Bats 

 immediately, no matter how frosty the previous nights and 

 days may have been. The reason why so few Bats were seen 

 during February was that the whole of that month — until the 

 last week, when they reappeared — was continuously cold." 



Discussing the possibility that not all these observations 

 referred to the present species, Mr Moffat admits that he is 

 unable to distinguish it from the Whiskered Bat, which also 

 occurs at Ballyhyland. But he contends that, although a few 

 of the latter may have been noted in his table as Pipistrelles, 

 yet his general results would not be thereby affected, and I 

 think the same remark applies to the records of other observers. 

 Most of the bats which he saw at low temperatures cannot, 

 he believes, have been other than Pipistrelles ; and in point 

 of fact he saw one captured on 28th December 1901, when the 

 temperature stood at 43^° Fahrenheit. 



Mr Moffat's conclusions may, I think, be regarded as 

 sound so far as concerns the winter flights of the Common 

 Bat in the south-east of Ireland, and his limitations may 

 be taken as approximately correct; in fact I can myself 

 corroborate them for the same county, where at Kilmanock 



1 Irish Naturalist, 1904, 81-87. 



2 The corresponding figures as given by Jenyns are 40° and 38° F. 



