178 RIVER AND POND DUCKS 



flight is usually performed by two males and one female. In the be- 

 ginning two males approached a female in the water, calling and bowing. 

 She usually rose at once and flew with a slow flapping flight, mounting 

 in the air with the males in pursuit, calling and whistling constantly. 

 First one and then the other of the males swung in front of her, set his 

 wings, inclined his body upward to show his handsome markings, and, 

 after a few seconds, dropped back again to his former position. Late in 

 the season there was always one of the males who was favored and who 

 displayed more often than the other, flying close to the female, so that 

 in passing his wings often struck hers, making a rattling noise. . . . 

 When the flight was over the birds descended swiftly to the water again. 

 . . . When the birds were in the shelter of the rushes they went through 

 other mating actions of interest. The male swam toward the female 

 bowing by extending his neck until the head was erect and then re- 

 tracting it, bringing his bill down onto his breast. He then approached, 

 pressing his breast against the sides of the female and shoving her easily, 

 first on one side and then on the other, biting her back and rump gently 

 as he did so. After a few seconds she lowered her body in the water and 

 copulation took place with the female entirely submerged save for the 

 crown of her head while half of the male was under water. As the female 

 emerged the male turned immediately to face her and bowed deeply, 

 giving a deep reedy call as he did so" (Wetmore, 1920). 



Whenever possible the Gadwall will choose an island as the site for 

 its nest and, failing this, will build in meadows or on the prairies, al- 

 ways on dry ground and never near to water. The nest is a scooped-out 

 hollow lined with the material of the immediate vicinity with which is 

 mixed down and feathers from the duck's breast; it is usually well con- 

 cealed under bushes or in thick grass, which is often arched over it. 

 The Gadwall lays from 7 to 13 dull creamy- white eggs but the usual set 

 is 10 or 11. The average size of the eggs is 2.18 by 1.56 inches. 



The actions of this duck when incubating are described by Dawson 

 (1909) as follows: "The bird's behavior when surprised depends alto- 

 gether upon the stage of incubation reached. In general, the bird sits 

 close until discovered; after that, if the eggs are fresh, the duck may 

 flee upon sighting her enemy a hundred yards away; but if the eggs are 

 near hatching, she will endeavour to lead the investigator astray by pain- 

 fully dragging herself through the grass. If too much harassed, however, 

 she will desert her eggs outright rather than wait for what she regards as 

 inevitable doom, and the same remark will apply to almost any of the 

 nesting ducks." 



The Gadwall is one of the few Surface-feeding Ducks that can and 

 does dive for its food, though this habit is only indulged in when abso- 

 lutely necessary; it usually feeds by dabbling in the marshes and sloughs. 

 Throughout most of the year its food is almost entirely vegetable, though 

 during the summer it consumes an appreciably higher percentage of ani- 

 mal matter. It walks well on land and often wanders far from water, 

 visiting fields of wheat, barley, buckwheat and corn and nearby woods 



