IN THE SHETLANDS 13 
many—cares, shadows, sorrows, they are easily multi- 
plied. 
A tern that either eludes or is not molested by 
a skua at sea, flies home with its fish, to feed its 
young. But here it has often to run the gauntlet of 
other skuas, who wait and watch for it upon the land, 
sitting amidst the short stunted heather, with the 
brown of which their plumage, as a rule, harmonises. 
There are, therefore, land-robbers and sea-robbers— 
pirates, and highwaymen—amongst these aristocratic 
birds, and it would be interesting to know whether 
the two roles are performed by different individuals, 
or indifferently by the same one. To ascertain this 
satisfactorily I have found a difficult matter, but 
I believe that here as elsewhere—in everything, as 
soon as one begins to watch it—a process of differenti- 
ation is going on. 
Where there are terns to be robbed, the skuas—I 
am speaking always of the smaller and, as I have 
found it, the more interesting species—seem to prefer 
them to any other quarry, so that the gulls, generally, 
benefit by their presence; otherwise all are victimised, 
except, as I think, the great black-backed gull. The 
latter will, himself, attack the skua, who flies before 
him, so that, taking this and his size into consideration, 
it does not seem very likely that the parts should ever 
be reversed between them, nor can I recall any clear 
instance in which they were. Of all the birds at- 
tacked, the common gull—which, like common sense, 
seems to be anything but common—makes, in my 
