222 
CHARADRIIFORMES 
Nesting. On ground, nest of seaweed or vegetable fragments. 
Distribution. Eastern Canada, breeds on the Atlantic coast from Nova Scotia north- 
ward along the Labrador coast. Owing to advancing settlement nesting localities have at 
present been reduced to the more isolated situations. Is a more or less regular but rather 
sparse winter visitor upon Lake Ontario, but rarely wanders farther inland along the 
Great Lakes. 
Economic Status . With similar feeding habits to those of the other 
gulls, the superior size, strength, and numbers of the Black-backed Gull 
increase its powers for good or harm. The species is certainly not to be 
trusted in the vicinity of unprotected nests of other species, or even young 
birds, as both eggs and young are eagerly devoured when opportunity 
offers. To offset this, however, the opportunity to become an important 
pest is small except in a few localities, as on the Labrador coast where the 
Black-back breeds abundantly in close proximity to great numbers of 
eiders and other sea birds. The damage it does on the Labrador coast, 
however, is small compared with the more serious and wanton waste of 
some of the fishermen. 
49. Western Gull, le Gotland de l'ouest. Larus occidentalis. L, 24. Like the 
Herriug Gull, but with a very dark mantle, lead-colour rather than light slaty or pearl 
grey. 
Distinctions. Dark, lead-coloured mantle, primaries black to base with only sub- 
apical white mirror or single outer feather (Figure 322). Juvenile birds seem almost 
identical with Herring Gulls of similar ages, but the browns are of a blacker and bluer shade. 
Field Marks. Dark mantle, when adult, with large amount of black with very little 
or no white to wing tips. The adult Herring and California Gulls, which are most likely 
to be mistaken for the Western Gull, have only the primary tips black. 
Nesting. On ledges, crannies, grassy hillsides, and similar localities by the sea. Nest 
of grasses, etc. 
Distribution. Western, from Washington to lower California. Occasionally wander- 
ing north to Vancouver Island. 
SUBSPECIES. The form accredited to Canada is the North-western Gull (le Goeland 
du Nord-Ouest) Larus occidentalis occidentalis. 
Figure 322 
Wing of Western Gull; scale, $. 
Most of the references in literature to this species on the British 
Columbia coast refer to the Herring Gull. On investigation it has been 
found to be very rare, though perhaps of regular occurrence after the 
breeding season. More information is desired concerning this species in 
Canada. At present we have only two localities absolutely substantiated, 
Comox and Clayoquot on Vancouver Island. 
51. Herring Gull, le Gotland argent^. Larus argentatus. L, 24. Plate XXVII B. 
Distinctions. Probably the commonest and most generally distributed gull in eastern 
and interior Canada. Several other gulls so closely resemble this species, except for size and 
slight colour details, that considerable care must be used in identification. In autumn 
and winter, adult has head and neck flecked with ashy brown. Similar to Glaucous- 
winged Gull shown on Plate XXVII A, except wing tip black instead of grey. 
