56 THE BIRDS OF THE BRITISH ISLES. 



nets sunk to fifteen fathoms, but confirmation is desirable ; in 

 clear water the bird may be watched swimming easily at a depth 

 of ten feet or more, but it is difficult to believe that it would, if 

 it could, dive so deep as ninety. Normally the dives do not 

 exceed fifteen seconds in duration. The Tufted's habits are 

 fairly regular ; as a rule most of the day is spent idly on the 

 water, the birds slumbering with the blue bill tucked into the 

 black back, floating lightly, small black and white buoys 

 swinging in the wind. Others attend to the toilet, rolling on 

 one side and showing the white under parts to perfection, as 

 they scratch neck or flank with a foot. Small wonder that 

 they are called "White-sided Ducks." Grebes careen to preen 

 and flash white in the same way, but even at a distance there 

 is a difference in the silky gloss of the Grebe and the dead 

 Chinese white of the Tufted drake. The social habit is well 

 d-evelopedjand flocks of considerable size consort with Pochards ; 

 the bird is seldom met with in any numbers on the sea. Towards 

 evening the flocks fly or swim to the feeding ground, which may 

 be on another lake or the shallower parts of that on which they 

 have spent the day, and again in the early morning the birds 

 usually feed. Tufted Ducks, however, may be seen diving for 

 food at all hours, often in little groups close inshore, vanish- 

 ing one after the other until the water swirls and eddies. 

 Aquatic weeds are their main food, but molluscs and insects 

 are taken. If alarmed the birds sink the body, stiften the neck, 

 and make for open water, but are slow to take wing ; when 

 they do they splash with wings and feet. Flocks on the wing 

 flash as they turn, but aerial gymnastics are not frequent ; 

 at times a flock will suddenly drop diagonally to a lower level 

 and at once resume horizontal flight, and the descent to the 

 water is swift and accompanied by a loud rushing sound. The 

 flight and alarm note are, to my ears, similar — a growling 

 currah or kiirr, but the breeding call is a soft, liquid puk^ with 

 a little of the Pintail twang. I have heard this from drakes as 



