350 Whitakcr : The Fliiyhl of Bats. 



so by means of very powerful and deliberate strokes of the 

 wint,'', lettini;;- each stroke carry it a considerable distance, as a 

 swimmer does in the water. This imparts to the flig'ht a 

 combined appearance of power and jerkiness. 



Even more noticeable than this, however, is its habit of 

 taking" sudden headlong", oblique plunges downwards through 

 the air, for a distance of anything from four or five to twenty or 

 thirty feet. During these dives the wings are held almost 

 fully extended, and flatly out from the body. The bat descends 

 edgeways, so to speak, that is, in the position offering least 

 resistance to the atmosphere. The dives are not vertical 

 descents, but are made at an angle of about sixty degrees, and 

 their object is to secure some insect which the bat has seen. 

 Immediately after thus plunging at an insect and securing" it, 

 the bat reascends to it previous altitude, seeming to prefer to 

 swoop down at its prey, like a hawk. Should it miss the 

 insect at its first attempt, it will sweep round in an ascending^ 

 curve until it has again attained a g"reater height before making" 

 a second attempt. 1 was once fortunate enough to see a 

 Noctule thus attacking a Poplar Hawk Moth which, owing to 

 its large size, was plainly visible to me during the whole of the 

 encounter, and I watched the bat repeat this manoeuvre four 

 times before it actually secured the moth. On another occasion 

 I plainly saw one thus catch a dor beetle which had just risen 

 from the g"rass near my feet. It is seldom that one can actually 

 see the insect the bat is swooping at, however, though the snap 

 of its teeth may often be heard. The Noctule is easily deceived, 

 and a pebble about the size of an ordinary marble thrown in the 

 air will usually be seen and dived at by a Noctule if there is one 

 near. The bat generally finds out its mistake when it has got 

 within a foot or so of the pebble, but will still often follow it 

 nearly to the ground ; I have only once got one actually to 

 catch a pebble. This was done within a few feet of my face, 

 and the bat evidently ' pouched ' the pebble [i.e. thrust it 

 into the skin which stretches between the hind legs, and 

 which forms a kind of bag or pouch when the animal bends 

 its legs forward), for it carried it some twenty feet before 

 dropping it into the reservoir on the edge of which I was 

 standing. 



To watch a Noctule dive at a pebble in this manner gixes 

 one a good idea of the tremendous speed it can attain when 

 sweeping through the air. For one of these bats, when at a 

 distance of thirty or perhaps forty feet, will often catch sig"ht of 



Naturalist 



