AND INCREASE OF CERTAIN BIRDS IN SCOTLAND. 55 
improve a salmon river. If the diseased and weakly birds 
and fish are taken from the moor and river, you have a 
more robust stock left to breed from, and the chances of 
disease are very much diminished. In a very interesting 
correspondence carried on in the Field newspaper this 
summer, it was demonstrated that a hawk will always of 
set purpose pursue the weakest bird which comes under his 
vision. One authority* said that he had seen Merlins (Falco 
zwsalon) frequently desist “from the pursuit of a fully- 
moulted lark in order to bestow their attentions on one still 
in the moult.” He then :adds that “the peregrine with her 
marvellous powers of vision and her experience of flying 
things . ... can detect in a grouse ....a weakness 
which disables him from shifting as well as his fellows.” 
And this writer goes on to ask, “ How does one rook in a 
flock know, before the hawk has begun to stoop, that he is 
going to be singled out as the quarry? How, but by 
knowing that he is, and that the hawk knows that he is, 
the weakest of the whole lot ?” 
Under the present system the weakly and diseased birds 
are sheltered and encouraged to breed. It needs no com- 
ment of mine to show you that this policy is unwise, and 
in the end defeats itself. 
3. Another cause of the decrease is man’s greed. 
People kill birds for their plumage; they trap them alive 
for their song; they wish to possess their skins or eggs. 
The man who can supply these demands gets money. 
Let me give an instance or two. Why is the Kingfisher 
(Alcedo ispida) a rare bird? Not because it is sometimes 
shot for feeding on trout-fry among its other food, but be- 
cause of its bright plumage. 
The man with a gun cannot keep his finger off the 
trigger if he sees a chance of “procuring” or “ obtaining ” 
(he does not care to say “ killing ”) such a beautifully-coloured 
bird, So the poor kingfisher is shot, and is then 
set in a stuffy little parlour to fade and become moth- 
eaten. 
I have seen a good deal of this bird lately, and really it 
* “Merlin,” in Field, July 9, 1898. 
