IN THE SHETLANDS 33 
mined way, and certainly pecked at it, though, at the 
distance, this was all I could say with certainty. It is 
interesting if a means of defence resorted to against 
animals only, by some colonies of these birds, is by 
others employed to repel the intrusion of man also. 
For the habit itself, I do not remember reading of it, 
either in the case of terns or any other bird or animal, 
except one with which Swift has made us familiar— 
Swift, that great misanthrope, who, by the sheer force 
of his satire, has anticipated to some extent the rea- 
soned truth of Darwin. As I say, I can hardly doubt 
that these terns acted as they did with malice pre- 
pense, yet, as their conduct is, perhaps, susceptible of 
another interpretation, I ought to mention that the 
bombardment was not continuous, but occasional only 
—a dropping fire, so to speak. As far as I could 
observe, however, the act was always in combination 
with the plunging sweep down, which makes me 
certain that, if not the mere mechanical effect of 
intense excitement, it was prompted by hostility—to 
which latter view I strongly incline. 
A little way farther on I found two quite tiny terns 
—the other was of a fair size—lying together in the 
nest. There was excitement when I took up these 
also, but not nearly so great as just before, except, 
perhaps, on the part of the two parents. The first 
young bird had assumed almost its final appearance, 
though not quite able to fly. I concluded, therefore, 
that this had something to do with the different degree 
of excitement shown by the terns as a whole, but 
D 
