SCAUP DUCK 259 



W. Thompson (1851) describes the noise that they made on a calm night in feed- 

 ing in the shallow pools exposed at low water on the sea-banks of Belfast Bay as 

 resembling the sound of a waterfall. 



Scaup sometimes move into lakes lying near the coast in severe weather on the 

 flood tide, and they do in fact often resort to fresh water quite regularly when it is 

 near the sea. 



Gait, Swimming, Diving. The gait is clumsy and waddling but perhaps no 

 more so than that of the Pochards. Although they certainly do not often "haul out" 

 on land I have seen them sitting on the bare point of a marsh in a certain bay in 

 Massachusetts. I think this happens only seldom, more commonly toward spring. 

 Millais (1913) speaks of having once seen a whole flock come in at low tide and 

 alight right on the flats among small pools and rills. In February, 1923, after a 

 very hard winter, I saw flocks of apparently very hungry birds do the same thing. 

 They came in from the bay and alighted on bare mud or in water only an inch or so 

 deep, where they fell to shoveling their bills along in the mud, like any surface- 

 feeder. And the curious thing about it was that they had not the slightest trouble in 

 landing on the bare flats, doing so as cleverly as Black Ducks. 



These ducks swim rather low in the water except when asleep or resting, when they 

 appear much more buoyant. 



They dive even more actively than Pochards and White-eyes; that is, they can 

 feed in even deeper waters and stay under longer. The wings are not used in pro- 

 pulsion under water, at least not by healthy birds, and Alford (1920) says that the 

 tail is spread and the legs shot out at right angles as with other diving ducks. I do 

 not know the maximum depth at which this duck is able to feed. It prefers depths 

 of four to ten or twelve feet, but can doubtless reach bottom up to fifteen or twenty 

 feet. Twenty-one feet was the greatest feeding depth that Dewar (1924) observed. 

 Naumann thinks 5.5 meters is about the limit. The ordinary period under water de- 

 pends, of course, on the depth, but from 15 to 30 seconds is the length of an ordinary 

 dive and 50 to 60 seconds has been recorded (Cordeaux, 1896). This last is certainly 

 exceptional. The longest that Dewar recorded was 49 seconds. I have seen them 

 making very short dives of six or seven seconds in very shallow water. When these 

 and other species are actively feeding the time taken up on the surface is only from 

 one-half to two-thirds as great as the time consumed underneath, but the greater the 

 depth the longer the pause between dives. 



Flight. This is not very different from that of other diving ducks. The start is 

 slow and " pattering " if the weather is calm, the first part of the flock rising long be- 

 fore the hindermost ones get under way, and the noise of a big raft starting to move 

 can be heard for miles. In a good breeze less effort is necessary. 



