166 LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS 



flock in a small tidal pool beside a grounded iceberg between Lyttleton Island 

 and Cape Hatherton, and Mr. MacMillan heard them whistling off Sunrise 

 Point. Returning from Cape Sabine to Cairn Point in mid-February, 1914, I 

 saw many guillemots in the open water along the edge of the young ice. On 

 March 1, 1914, Doctor Hunt, the surgeon of our party, shot 19, all in winter 

 plumage, in open leads off the mouth of Foulke Fjord, where many flocks of 

 them were feeding. 



The fall migration of this species is not very extensive, so far 

 as it is known, for it can be driven from its summer home only when 

 the ocean is solidly frozen. Probably most of the Greenland birds 

 are forced out to winter on the open ocean or around the edges of 

 the ice packs. The birds which breed north of Hudson Bay prob- 

 ably do not migrate through Hudson Strait, but winter in the south- 

 ern part of Hudson Bay or in James Bay, which is almost always 

 more or less open; the occasional freezing of this bay may account 

 for the accidental occurrence of this species in Ontario. Mandt's 

 guillemot winters in Bering Strait, but does not seem to wander south 

 of Norton Sound, Alaska. 



Cepphus mandti will probably prove to be a subspecies of Cepphus 

 grylle. Numerous specimens of intermediate birds are to be found 

 in collections, which are either intergrades or hybrids. Two summer 

 birds from the Gulf of St. Lawrence, which I have seen, show the 

 intermediate characters. 



DISTRIBUTION 



Breeding range. Coasts and islands of the Arctic Ocean. From 

 northern Greenland (Cape Union, Thank God Harbor, Bessells Bay, 

 and Cape Lieber south to about Disco Bay), Spitzbergen, Franz 

 Josef Land, Nova Zembla, the northern Siberian coast to Herald 

 and Wrangel Islands, the vicinity of Point Barrow, Alaska, and 

 islands north of Hudson Bay. South along the west coast of Ungava 

 into James Bay. Birds have been recorded as far north as latitude 

 84. Nonbreeding birds may occasionally be found in Bering Sea 

 and on the coast of Labrador (Cape Whittle, June 24), but breeding 

 records from these localities need confirmation. Has been taken at 

 Gaspe, Quebec, June 10. 



Winter range. As far north as open water can be found, south 

 to Bering Strait (rarely Norton Sound) and Hudson Strait. Many 

 doubtless winter in Hudson Bay and James Bay, occasionally reach- 

 ing Lake Ontario, and some probably occur on the Labrador coast 

 at this season. 



Spring migration. Arrive in northern Greenland; Bowdoin Bay, 

 May 8 (not common until late June) ; Thank God Harbor, February 

 28 and during March; Cape Sabine, first seen March 15 ; northeastern 

 Greenland, latitude 80 10', June 10. 



Fall migration. In northern Greenland last seen at Floeberg 

 Beach, latitude 82 27', August 29; at Port Foulke, September 1; 



