JUN 2 1905 



May, 1905. The Irish Naturalist. 



97 



THE DURATION OF FLIGHT AMONG BATS. 



BY C. B. MOFFAT. 



(Read before the Dnbliu Naturalists' Field Club, 21 March, 1905.) 



1 AM not sure that the subject of Bats is of interest to most 

 people, or even to most naturalists ; but to me they have always 

 been fascinating animals, and. it surprises me to find, from 

 time to time, how very little is known about them. Some 

 years ago attention was drawn by Dr. N. H. Alcock, at that 

 time one of the hon. secretaries of this Club, in a most interest- 

 ing introduction to a series of articles which he unfortunately 

 has not had time to complete, to the extraordinary dearth of 

 our information about Bats, and particularly about the.habits 

 of Bats. For one thing — Are they nocturnal creatures or are 

 they not ? We all know that it is their usual practice to come 

 out of their sleeping places a little after sunset, some kinds 

 being rather earlier than others ; but Dr. Alcock showed that 

 scarcely anything was known concerning their further move- 

 ments. He raised the question, "How long do Bats fly?" 

 After setting out on their after-sunset excursions, do they 

 *' not go home till morning," or do they just fly while there is 

 enough lingering twilight to guide their entomological 

 pursuits ? Surely it was a singular thing that such a question 

 could need to be asked in one of the closing years of a 

 century famous for devotion to zoological research. Yet 

 there was then only one British Bat concerning whose habits 

 anything definite could be stated, and I have reason to believe 

 that only half the truth had been ascertained about it. I refer 

 to the Noctule — a species which happens not to be found in 

 Ireland. The Noctule had been repeatedly seen by various 

 observers returning to its den before the twilight was quite 

 gone ; in fact, its whole flight occupied only about an hour. 

 It is, doubtless, well known that the Noctule is a very large 

 Bat— it is the so-called " Great Bat" of Gilbert White's delight- 

 ful Selborne letters — and in consequence of its superior size 

 it can be seen entering its sleeping place at hours when the 

 Pipistrelle or the lyong-eared or the Whiskered Bat would be 



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