304 Wild Life in Wales 



leading a less exposed life ; but, however that may be, she 

 must fly in order to deposit her eggs, which are dropped 

 singly over the water ; and when engaged in that occupa- 

 tion, how many of her sex must fall a prey to the ever- 

 watchful trout, just at the very moment when on the 

 preservation of her life hangs the welfare of the future 

 generation ! 



The Sand Martins were all left roosting by the margin of 

 the lake ; as we walked home by the river side, little flocks 

 of Swallows were disturbed from every bush of alder, or 

 sallow, that overhung the water. This is always the 

 favourite roosting quarters of these birds, as soon as the 

 breeding season is over ; the closer the boughs hang to the 

 water, the more they seem to be preferred, but I have often 

 wondered what it can be that prompts the choice. Is there 

 any enemy which instinct leads them thus to avoid, and, if 

 so, what can it be ? Can it be those " policemen of the 

 night," the prowling Owls, to whom the risk of a wetted 

 plumage may be a deterrent, but to whom the Swallows, 

 sitting upon the rather bare branches they usually affect, 

 might otherwise prove a tempting and conspicuous prey ? 

 Or is it simply the survival of a habit, begotten of long 

 residence in tropical climes, where other enemies have to be 

 guarded against, that is too deeply ingrained to be lightly 

 cast aside, even although the causes of its acquisition do not 

 exist in this country ? 



