91 
148. Greater Scaup Duck, scaup duck, bluebill. broad-bill, lake bluebill. 
Marila marila. L, 18-50. Like a larger edition of the Scaup Duck shown on Plate X A. 
Distinctions. Difficult to separate from the Lesser Scaup, but larger. Male with green- 
ish instead of puipie reflections on head. In any plumage exoept occasional joung birds, 
distinguished from the Lesser Scaup by 
the white to near-white on the outer webs 
of the inner primaries (Figure 125, compare 
with Figure 126). In the Lesser Scaup 
this light spot may be represented by a pale 
area, but it does not reach the clear wnite 
of this species. The females resemble the 
females of several other species, but can 
be separated from all except the female 
Lesser Scaup and the Ring-neck by the 
white spot at base of the bill, and from 
the latter, together with the Redhead and 
Canvas-back, by the white instead of grey 
Bpeculum. 
Field Marks. In general the adult male 
Scaups appear black for the front half of 
the body and white for the remainder, a 
colour pattern visible at a considerable distance. At rest, distinguished from the male 
Ring-neck by light instead of black back; in flight in any plumage by white instead of 
grey speculum. An experienced eye can sometimes tell the two Scaups apart in life by 
the white on the primaries as above, otherwise, as small differences in size are very 
deceptive, they are probably inseparable in the field. The female is distinct from all white- 
bellied brown Ducks except the Lesser Scaup and the Ring-neck by the white spot at the 
base of the bill, and from the latter and the Redhead and Canvas-back by the white 
instead of grey speculum. 
Nesting. On the ground, near grassy ponds. 
Distribution. Common to New and Old Worlds. In America, across the continent. 
Many of our breeding records for this species have been confused with the next. We have 
no authenticated nesting record from the prairies or British Columbia where it seems 
to be a migrant only. Known to nest north at least as far as Great Slave lake. It is more 
common on the coast than in the interior. 
Much information founded on accurate specific identification is 
desired as to the occurrence, nesting, and migration of this species. It is 
more of an open or large water bird than the Lesser Scaup, but is often 
found in the marshes and shallows in company with it. 
149. Lesser Scaup Duck, bluebill. broad-bill, little bluebill. marsh 
bluebill. Marila ajffinis. L, 16 • 50. Plate X A. 
Distinctions. Difficult to separate from the Greater Scaup, though slightly smaller. 
Male: with purplish instead of greenish re- 
flections on head. In any plumage except 
occasional young birds distinguished from 
the Greater by the absence of white or 
near-white on the outer web of the inner 
J rimaries (Figure 126, compare, with 125). 
n this species this area may pale a little, 
but it never approaches the whiteness of 
the Greater Scaup. The female resembles 
the female of several other species, but 
may be separated from all except the 
Ring-neck by the white spot at base of bill 
and from that species together with the 
Redhead and Canvas-back by the white 
instead of grey speculum. 
Field Marks. In general, male Scaups 
appear black for the front half of body 
and white for the remainder, a colour 
pattern visible at considerable distances. 
At rest, distinguished from the male Ring-neck by light instead of black back and in 
flight, in any plumage, by the white instead of grey speculum. An experienced eye can 
Figure 126 
Wing of Lesser Scaup Duck; 
scale, about $. 
Figure 125 
Wing of Greater Scaup Duck; 
scale, about j. 
