LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 199 
pursuit. The presence of dead birds about the rookeries indicates 
that deadly combats may sometimes occur. 
Winter—During mild winters the Pallas’s murres often spend 
the winter not far from their summer homes in the southern por- 
tion of Bering Sea, but they ordinarily winter about the Aleutian 
Islands, where the water is usually open, or on the North Pacific 
Ocean. It is interesting to note in this connection that, whereas the 
Briinnich’s murre winters much farther south than the common 
murre on the Atlantic coast, the Pallas’s murre winters much farther 
north and apparently not far from its breeding range. 
DISTRIBUTION. 
Breeding range.—Coasts and islands of the North Pacific, Bering 
Sea, and western Arctic Ocean. From Kodiak, the Aleutian and 
the Commander Islands northward throughout Bering Sea; and in 
the Arctic Ocean from .Wrangel and Herald Islands, and Koliut- 
schin Island, Siberia, to Kotzebue Sound and Cape Lisburne, Alaska. 
Recorded in summer from Kamtschatka, Kurile Islands, and Japan 
(Yezzo), where they probably breed, 
Winter range—The open sea about the Aleutian and the Com- 
mander Islands, and probably along part of the coast of southern 
Alaska to Seymour Narrows and to southern Japan. In favorable 
seasons birds occur north to the Pribilof Islands. 
Spring migration—Birds arrive on their breeding grounds, Bo- 
goslof Island, April 26; Pribilof Islands, April 1 (first taken) ; St. 
Michael, last of May (sometimes earlier) ; Kotzebue Sound, Cha- 
misso Island, June 6; Point Hope, April 14 (earliest). 
Fall migration—Birds leave their nesting places in Bering Sea, 
beginning in August, but the colonies are not deserted until the mid- 
dle of September or later. 
Egg dates.—Bering Sea Islands: 25 records, June 2 to September 
1; 13 records, June 18 to July 12. North of Bering Strait: 7 records, 
July 3 to August 8; 4 records, July 6 to August 1. South of Alaska 
Peninsula: 6 records, June 10 to 26; 3 records, June 18 to 24. 
ALCA TORDA Linnaeus. 
RAZOR-BILLED AUK. 
HABITS. 
Far off to the southward of Grand Manan Island an outlying 
group of rocky islands, the Murre Ledges, mark the entrance to the 
Bay of Fundy. The outermost and southernmost of these is known 
as Yellow Ledge; it isa low, flat rocky island, about half an acre in 
extent at high tide, and is covered with a mass of loose rocks and 
bowlders. Here on June 17, 1891, I first made the acquaintance of 
