[Cit.vv. VMI, 32 



1>A u.vs. '22 \- 2-a:\ 



The Pochards (and another class of Ducks with 

 wliich we are not concerned liave the outer jjrimaries 

 iiiinilar to Lf.oi-e uf the. Tnte Duck^ hut the iimer firimnrieH 

 0/ the some xilnte or pale colour as the SfL^ecuhnn, hut tipped 

 with rivsku. 



The .Scaup Ducks, in whicli Oates inehides one ot 

 the species, viz., the Tufted Duck, treated in this book ; 

 " have the primaries very similar to those of the Pochards, 

 but the injier ones, instead of being white or of a pale 

 colour on both webs, have only the outer web white or of a 

 pale colour, the inner web being dark." 



KEY 8. 



7. Primaries uniform ivithout a pattern. — 

 Spotbill (Kesident, or of limited migration). Marbled 

 Duck. 



//. Primariefi luith outer iveb of vf>y dark colour 

 and inner weh of a dusky colour with dmk tip. — 



All the True Ducks — Highly migratory and rapid- 

 Hying. 



///. Outer primarief: an in II above, hut inner pri- 

 maries of same xchlte or pale colour as speculum but tipped 

 with dusky. — 



All the Diving Ducks. 



Exception. — The Tufted Duck, called by some a Scaup 

 Duck, which has inner primaries witli outer web white 

 or much paler than the inner. 



Similarity or 23. Among the Surface-feeding Ducks, tlu'ee species 



dissimilarity are alike in the colouring of the sexes, z'is., the Spotbill, the 

 hico'lou^rlng. Gadwall and the Marbled Duck, while all the rest are 

 (Key 9V° unlike. The Diving Ducks have the sexes dissimilar, 

 but there is not the broad difference that the True 

 Ducks show, where nature, wdiile endowing the males with 

 brilliant colours, has left tlie females drab and incon- 

 spicuous by comparison. Tlie most striking examples of 

 the latter phenomenon among the Ducks treated are the 

 Mallard, the Common Teal, the Wigeon, the Shoveller 

 and the Red-crested Pochard. 



KEY 9. 



/. (Sexes uiik", or nearly alikr. — 



Spotbill. ! Uadwall. 



Marlilcd Duck. 



fl. ^ecrcs di'<iiimilui . — 

 The rest. 



Note.— The Diving Ducks sliow liowever rather less dififeieuce 

 between the .Se.xes thau most surface-feeders do 



