46 
27. Black Guillemot. PIGEON. SEA PIGEON. FR.—LE GUILLEMOT NOIR. Cepphus 
grylle. WL, 13. In summer the Black Guillemot is a small, coal black diver with large 
white wing patches and red feet. In winter the underparts are white and the feathers 
above are black but broadly tipped with white. The wings remain as in summer. 
Distinctions. In summer the species cannot be mistaken for any other. In winter, 
the size and wing coloration are almost equally distinctive. 
Field Marks. The characters above make easily recognizable field marks. 
Nesting. In cavities in the rocks or in openings in the rough talus at the foot of sea 
cliffs. 
Distribution. The Atlantic Guillemot is common along our Atlantic coast but is 
rarely if ever seen inland. 
SUBSPECIES. There are two subspecies of the Black Guillemot in Canada, the 
Atlantic Guillemot, the type form, and Mandt’s Guillemot, Cepphus grylle mandti, a 
northern race inhabiting Arctic regions and distinguished by having all the wing coverts 
white to the base instead of with a concealed dark wing bar. This form is given by 
the American Ornithologists Union check-list as a full species, but should probably be 
reduced to subspecifie status. 
The Black Guillemot is one of the commonest inhabitants of our sea 
coast and is known to nearly all who visit there. It is less gregarious than 
the other members of the family and usually nests alone and not in rookeries, 
though sometimes numbers are drawn together in localities by a community 
of interest. 
30. Common Murre. FR.—MORMETTE. LE GUILLEMOT ORDINAIRE. MARMETTES. 
Uria troille. LL, 16. The Murre in summer is white below, with the head and neck dark, 
smoky, seal brown. The back and wings are black. In winter the throat is light, veiled 
with more or less greyish, and the brown is replaced on the head and neck with black more 
or less shaded with grey especially on the throat. 
Distinctions. The Common Murre is very much like Briinnich’s Murre and the Razor- 
billed Auk. Can be differentiated in summer from the former by the lighter brown colora- 
tion of the head and neck and by the fact that the back of the neck is not darker than the 
front. At all seasons it has a somewhat shorter and decidedly heavier bill. From the Auk 
it can be told by its bill which is not markedly flattened or deepened. 
Field Marks. Bill sizes and neck coloration are the only field marks that can be given 
to separate the two Murres and in life these can only be seen under the most favourable 
circumstances. The birds are said to swim with level instead of up turned tail as does the 
Razor-bill. The difference between the latter’s bill and that of the Murre, however, is 
quite obvious under ordinary conditions. 
Nesting. In large colonies amongst the rocks, making no nest and laying only a single 
egg. 
Distribution. Abundant along the eastern sea coast, never or rarely ever being found 
in the interior on fresh water. 
SUBSPECIES. The Common Murre inhabits the northern parts of both Pacific and 
Atlantic oceans, being represented by different subspecies.in each. The Atlantic Murre 
is the type form and is, of course, the one that occurs on our eastern coasts. 
The number of Murres that will occupy a nesting ledge is sometimes 
remarkable. At the edge of the rocky shelves they gather as close as they 
can stand, like files of soldiers, bearing strong resemblance to the lines 
of penguins that are familiar to us in pictures. 
31. Thick-billed Guillemot. BRiiNNICH’S MURRE. FR.—LE GUILLEMOT DE BRUN- 
nich. Uria lomvia. L, 16°50. This Murre is almost exactly similar to the preceding 
species. 
Distinctions. Head and neck are darker and richer brown without the smokiness of 
the Common Murre and the neck is somewhat darker behind than in front. Bill is some- 
what larger and noticeably heavier. 
Field Marks. Longer, heavier bill and coloration of the head and neck will under 
exceptional visual conditions separate this bird in life from the Common Murre. Sharp 
and tapering instead of blunt and deep bill, and tail not turned up in swimming, should 
serve to distinguish it from the Razor-billed Auk. 
