138 ANATID/E 
it from other Ducks, while its habits of diving exclude the 
possibility of its being mistaken at a distance for any of the 
Wild Geese. 
Food.—Kider Ducks are constantly plunging under water ; 
they descend to a great depth and remain beneath the 
surface for a considerable time, snatching mussels (their 
staple diet) from off the rocks. They also eat crabs, cray- 
fish, and a small quantity of seaweed. 
The flesh, rank and fishy, is eaten by the Greenlanders. 
Voice.—The voice is low and murmuring, resembling the 
syllable curr, softly produced; as a rule, the bird keeps 
silent unless alarmed. 
Flight.—The Eider Duck can travel at a consider- 
able speed on the wing, still the flight 1s heavy and not 
buoyant. 
Nest.—Though this bird builds on the ground, its nest 
may be found on cliffs, hundreds of feet above the sea-level. 
But the more usual site selected is a low, flat-topped island, 
fairly clad with marine vegetation, in clumps of which the 
nest may be placed. Sometimes a crevice between rocks or 
loose stones 1s utilised. The materials are dry grass and 
seaweeds, to these, which form the foundation, bits of 
heather, stems, and campion, are sometimes added. The 
nest is thickly lined with grey down, the well known Eider- 
down of commerce ; as incubation proceeds the mother-bird 
continues to add more down to the nest.’ 
Incubation begins. about the end of May and lasts for 
twenty-eight days. During all that time it seems evident 
that the hatching-bird abstains from food, a fact which 
has been vouched for by observations made on birds in 
captivity (Payne-Gallwey, ‘Letters to Young Shooters,’ Third 
Series, p. 173). 
The eggs, five to eight in number, are usually of a lght 
olive colour, but the shade varies even in the same clutch. 
The sitting-bird is often remarkably tame (especially in 
countries where the Eider Duck is protected by law), and 
' It may be mentioned that the down which is so characteristic a 
feature of the lining of Ducks’ nests, is plucked by the mother-bird from 
her own breast. The down of aquatic birds is remarkably light and soft, 
and retains among the interstices of its fibres, the heat given out from 
any body with which it is in contact. The softness, lightness, and 
elasticity of Hider-down, with its wonderful heat-retaining properties, 
renders it a highly-prized material for coverlets. 
