194 THE SHELDUCK AND SUKFACE-FEEDING DUCKS 



and as a rule a plentiful supply of down, which is dark brown in bulk, with fair-sized 

 light centres and whitish brown tips. The nest feathers are more pointed than 

 those of the Pintail, and are marked with a double brown bar (the upper one being 

 sometimes represented by two spots) and a fan-shaped extension down the shaft to 

 the tip. (Pis. U and LXVI.) The nest is made by the duck alone, and contains as 

 a rule from 8 or 9 to 14 eggs, exceptionally as many as 16. The colour varies con- 

 siderably ; it is usually greenish grey or yellowish grey, occasionally pale blue-green 

 or greenish white. Average size of 270 eggs, 2-21 x 1 -61 in. [56*3 x 40-9 mm.]. (PI. T.) 

 Incubation is performed by the duck alone, and lasts 25 to 26 days (W. Evans). 

 Heinroth also gives 26 days, but O. A. J. Lee states that the average period is 

 25 days, but that some eggs hatch on the 22nd day. They are laid in the British 

 Isles from February onward to June, but the most usual time is from the end of 

 March to mid- April. In the Shetlands eggs may be found from mid-May to the 

 end of June (Saxby). Exceptional cases have been recorded of autumn breeding, 

 hi September and even in October. Normally the mallard is single brooded, and 

 eight to ten weeks elapse before the young can fly, so that the late hatches are 

 probably those of birds which have lost their first sittings, though it is of course 

 possible that some birds may attempt to breed twice. [F. c. B. J.] 



5. Food. Minute organisms obtained by passing water and ooze through 

 the beak, aquatic insects and their larvae, worms, slugs, small frogs, small fish, 

 leaves and seeds of aquatic plants, grain, and acorns. The young feed largely on 

 insects, under the guidance of the female, and in the fledgling stage obtain much 

 food by diving, wherein they differ from the adults, [w. P. P.] 



GAD WALL [Anas strepera Linnaeus. Bastard (Kent). French, chipeau- 

 bruyant ; German, Mittel- or Schnatter-Ente ; Italian, canapiglia]. 



I. Description. The gadwall may always be distinguished by the colora- 

 tion of the speculum, the inner half of which is white, the outer black. In front 

 it is bounded by a wedge-shaped patch of black passing towards the tip of the 

 outstretched wing into Indian-red. The sexes differ in coloration, and there is 

 a conspicuous seasonal change of plumage in the male. (PI. 158.) Length 20 in. 

 [508 mm.]. The male has the base of the hind-neck, scapulars, and flanks marked 

 by coarse vermiculations of black and white, and the minor coverts rich Indian-red. 

 The crown is black, more or less markedly barred with brown, and the side of the 

 head and neck are buffish white, mottled with brown. The fore-breast is white 



