196 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



" whenever the winter home of Ross's gull is discovered, Sabine's gull 

 will probably be found there also, for the two species arrived to- 

 gether at the mouth of the Kolyma Kiver, Siberia, the 1st of June. 

 1905, and were together when seen in migration in May several hun- 

 dred miles west of that district." 



DISTRIBUTION. 



Breeding range. — Arctic coasts of both hemispheres. In the West- 

 ern Hemisphere, east to northeastern Greenland (Cape Bismarck). 

 South to central western Greenland (Upernavik) , northern Hudson 

 Bay (Southampton Island), Boothia Peninsula, Victoria Land (Cam- 

 bridge Bay), northern Mackenzie (Franklin and Liverpool Bays), 

 northern Alaska (Point Barrow and from Norton Sound to Hooper 

 Bay), and St. Lawrence Island, Bering Sea. In the Eastern 

 Hemisphere it is known to breed in northeastern Siberia (near 

 Bering Strait), in northwestern Siberia (Taimyr Peninsula) and 

 on Spitzbergen. The northernmost breeding record is at Thank 

 God Harbor, northern Greenland, 81° 40' North. 



Winter range. — The only known winter range seems to be on the 

 coast of Peru from Tumbez to Callao Bay. 



Spring migration. — Northward along both coasts and in the interior 

 of North America. Dates of arrival : Maine, Scarborough, May 31 ; 

 Cumberland Gulf, June 15 ; Melville Peninsula, Winter Island, June 

 29 ; Ellesmere Land, Fort Conger, July 6 ; Illinois, Chicago, April 1 ; 

 Manitoba, Norway House, June 11; California, Monterey, April 9 

 o^l to May 21 ; British Columbia, Bell^Bella, May 24 ; Yukon, Chilkat 

 / Inlet, June 1 ; Alaska, St. Michael, May 7 to 25, Point Barrow, June 

 2 to 6, and Demarcation Point, May 28. Some birds remain in 

 Peru until April. 



Fall migration. — Southward by same routes. Dates of arrival: 

 Maine, Portland, September 22; Massachusetts, August 21 to Sep- 

 tember 27; New York, Long Island, October 7; Iowa, Burlington, 

 October 12 to 15; Nebraska, September 2 to 30; Washington, Shoal- 

 water Bay, September 24; California, Monterey, July 22. Dates of 

 departure: Melville Peninsula, Igloolik, August 13; Greenland, 

 Kikkerton Island, October 6; Alaska, Point Barrow, September 17 

 to October 22; California, Monterey, October 28. 



Casual records. — Accidental in Bermuda, Switzerland, and Austria- 

 Hungary. Occasional in winter in British Islands and northern 

 France. 



Egg dates. — Northern Alaska: Eight records. May 28 to July 6; 

 four records, June 8 to 28. Northern Mackenzie: Seven records, 

 June 20 to July 10 ; four records, July 5 to 7. 



