GREATERSCAUP 249 



tip, and deeper and heavier at base (fig. 46), nail, wider and larger; eye, same as 

 that of Lesser Scaup. Body, same as that of Lesser Scaup, except sides, whiter. 

 Tail, same as that of Lesser Scaup. Wings, same as those of Lesser Scaup, except 

 that a few of the inner primaries are white like the secondaries (fig. 47). (See 

 Lesser Scaup Duck.) 



ECLIPSE PLUMAGE: Same as that of Lesser Scaup Duck. 

 AUTUMN PLUMAGE: Same as that of Lesser Scaup Duck. 



ADULT FEMALE. Identical in colour with female Lesser Scaup Duck; the 

 more pronounced whitish area on the primaries, and the bill (see male) being 

 the best distinguishing features. The head of some Greater Scaups is sepia, darker 

 than that of female Lesser Scaup. (See Lesser Scaup.) 



JUVENILE. The sequence of plumage changes is the same as in the juvenile 

 Lesser Scaup Duck. 



SPECIMEN IDENTIFICATION 



See Lesser Scaup Dck, under which species the distinctions are fully de- 

 tailed. 



FIELD MARKS 



ON THE WATER AND IN FLIGHT. Greater Scaups are difficult to dis- 

 tinguish in life from Lesser Scaups except under the most favourable conditions. 

 They are, however, the Scaups of the coasts and the larger bodies of inland water, 

 while the Lesser are abundant everywhere inland on the smaller bodies of water 

 and in the marshes. To distinguish on the water and in flight from the Lesser 

 Scaup and other species see Lesser Scaup Duck. 



VOICE. A loud, discordant scaup, scaup, and a purring pbbbbrr, oft re- 

 peated in flight. Courtship voice of male, a gentle pa-whoo; the female responds 

 chup-chup or chup-chup-cherr-err or tuc-tuc-turra-tuc. 



LIFE STORY 



The Greater Scaup Duck, or "lake blue-bill" as it is commonly 

 called, is closely related to the European Scaup. It probably derived 

 its name from its habit of feeding on oyster or mussel beds, which in 

 Europe are called "scaup" and in Scotland "scalp" beds; the term is 

 of the same derivation as "scallop," the name of a well-known shellfish. 

 Or the name may have been given on account of the bird's characteristic 

 call scaup, scaup. Or both. It is very similar to the Lesser Scaup or 

 "little blue-bill" and in life is difficult to separate with certainty. The 

 distinctions between the two species are dealt with fully under "Speci- 

 men Identification" of Lesser Scaup. The Greater Scaup will average 

 about one-quarter pound heavier than its smaller relative but the sizes 

 intergrade to such an extent that this is not a determining factor. It 

 is a much more northern breeder than the Lesser Scaup, and is distinct 

 in many of its habits and its behaviour. Its migration routes are differ- 

 ent, it winters further north on both coasts and it is more of a maritime 

 species. On its migrations it frequents the lakes, large ponds and rivers, 

 feeding and resting on the larger waters, where it gathers in huge flocks 

 or "rafts" during the day. 



