Family ANATIDAE. 



Chaulelasmus strepera (L.) — Gadwall. 



(Plate 184, fig. n-c). 

 (Snoiickacrt: Avifauna Neerlandica, p. 126, No. 302). ') 



Colour of surface of shell: 



Average dimensions: 

 Average weight of shell: 

 Texture of shell: 



Shape : 

 Nest: 



Down (in bulk): 



Small feathers: 



Site of nest: 

 Number of eggs: 

 Breeding season: 

 Duration of incubation: 



ranges from yellowisli to pale greyish green. 

 Certain authors wrongly assert that a 

 greenish tint never occurs in these eggs. 



54 ; 37.5 millimetres. 



about 4 grams. 



fine and smooth ; to the aided eye it appears 

 still more finely granulated than that of 

 A. boschas, to which, for the rest, Ch. 

 strepera is closely allied ootogically. 



usually blunt oval; sometimes elliptical. 



consist of vegetable materials, lined with 

 down; it is lined with down more abun- 

 dantly than that of A. boschas. 



dark brownish grey, with small lighter centra, 

 topped with grey. 



white at the base, spotted dark irregularly 

 in the centrum, lighter towards the top. 



on the ground, among grass, sedge, etc. 



usually 7-10 (sometimes more). 



May, June. 



about 27 days. 



') See also Dr. E. D. VAN OoRT'S communication in the : „Jaarboekje der 

 Ned. Ornithol. Ver." No. 8, p. 2C. 



