BATS. 



83 



observer will not watch his movements long on such occa- 

 sions without noticing a manoeuvre which at first looks like 

 the falling of a tumbler pigeon, but on closer observation 

 proves to be simply a closing of the wings and a consequent 

 drop of about a foot. Sometimes this is repeated every few 

 yards as long as in sight. It is occasioned by some large 

 and intractable insect having been captured, and the anterior 

 joint of the wing, with its well-armed thumb, is required to 

 assist in retaining it until masticated." 



To prevent confusion it may be here stated that, although 

 Britain seems to have a proportionally large number of 

 species of bats, yet some of these, like the Hairy-armed 

 (y. Leisleri)^ Serotine (F. serotiniLs)^ and Parti-coloured 

 Bat (F". discolor)^ 2ire exceedingly rare. 



Every agriculturist will frequently have noticed the 

 Commcn bat (F. pipistrelliLs) hawking for flies ; and 

 various dipterous insects, which are its main food, are 

 specially injurious to farm crops. It is particularly noticeable 

 in the common bat that it spends the twilight hours mainly 

 round farm steadings and buildings which house cattle, and 

 is thus always near its food-supply. Individuals in confine- 

 ment take large numbers of house-flies on the wing, and are 

 not averse to small pieces of meat. It is from keeping bats 

 in confinement that much of their life-history has been 

 learnt — among other facts the interesting one that they 

 produce but a single young one at a birth. For a time the 

 young one sticks closely to its mother's breast, and, when 

 not suckling, is kept carefully tucked up in one of the wing 

 folds. 



Whilst several of the rarer bats are extremely local in 

 their distribution, it often happens that these exist in con- 

 siderable numbers in particular districts. An illustration of 

 this may be given in connection with the Mouse-coloured 

 bat {Vespertih'o viiinniLs)^ referred to above. This species is 

 particularly fond of the nocturnal Lepidoptera, the wing- 



