28 THE 15IRDS OF THE BRITISH ISLES. 



many remain until April and May; parties of migrants are 

 about long after our resident birds have begun nesting. All 

 sportsmen agree that "foreign" Mallards are smaller and 

 lighter than our birds, but no racial difference has so far been 

 discovered. Marking birds has demonstrated that some of our 

 immigrants come from Scandinavia, Lapland, and Holland, 

 and British birds have been found in Germany and Fiance. 

 The voice of the drake is a low, conversational chuckle during 

 the breeding season, with an occasional sonorous quack. But 

 when the birds are startled it is the duck which quacks in alarm, 

 but in a different tone. Seebohm spells the male note quark, 

 and the female quark, a good distinction. When pairing the 

 drake also whistles. Pairing begins early ; I have often 

 watched display in October. A number of drakes swim round 

 a duck, posturing in various ways, but the sequence of actions 

 is not always the same. The bird sits up in the water, as if 

 making its seat more comfortable, and dipping the head, strokes 

 its breast with its bill. It raises and fans its tail, showing 

 off the white, and stretches its neck along the water as a final 

 compliment to its selected mate. 



Incubation often begins in March. The nest is usually at 

 a short distance from the water, in thick vegetation, in woods, 

 dry reed or willow beds, hedgegrows, or in heather on the 

 moors. Sometimes it is in the fork of a tree or the deserted 

 nest of some large bird. Grass and dead leaves are the usual 

 materials used, and a lining of dark brown down is added as 

 incubation proceeds, with which the eggs are covered when the 

 duck leaves them ; when she is silting (I'late ii) her sombre 

 dress is sufficient protection. The eggs (Plate 13), eight to 

 fourteen in number, are variable — greenish blue, olive-brown, 

 cream, or white. The normal moult begins in August, and by 

 the end of September most drakes are in full dress. The 

 spring moult of drakes is incomplete, but in ducks it even 

 includes the down. In May the drakes assume the so-called 



