200 BRITISH SEA BIRDS. 
period, becomes absurdly tame in districts where 
not persecuted, often allowing an observer to 
stroke her gently whilst she sits upon her eggs. 
The food of the Eider Duck consists of minute 
marine insects, crustaceans, and shellfish, especially 
mussels and small crabs. Most of this food is 
obtained by diving, the Eider being marvellously 
expert at this, not only descending toa great depth, 
but remaining for a long time below. A favourite 
method of feeding with this species is to draw 
shorewards with the tide. It may be watched 
gradually swimming towards the land in some 
sheltered bay, feeding as it comes, until the very 
edge of the breakers is reached. Then comes by 
far the prettiest sight of all, as the bird swims 
through each mighty wave just before it turns over 
and breaks upon the beach, floating light as a foam 
fleck on the huge rollers, now high up on the white 
crests, then momentarily lost to view in the green 
glassy depths. If alarmed on these occasions, the 
Eider generally swims quickly out from shore, but 
if further pursued or fired at, it instantly takes wing, 
rising from the water with little splash, and flying 
rapidly and steadily just above the surface to a 
safer refuge. The Eider is a day feeder, abroad at 
dawn, and continuing its labours well into the dusk. 
As a rule the Eider is a very silent bird. The 
usual note is a somewhat low urr, but in the 
season of courtship the male utters a cooing sound 
when paying his addresses to his mate, as he swims 
