10 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



Bering Sea. It has been recorded as breeding on the coast of Alaska 

 (Deering, Kotzebue Sound, and Muller Bay). 



Migration. — Very little information is available concerning the 

 movements of the gyrfalcons. In the fall of 1905 there appears to 

 have been a rather extensive southern movement in both Europe and 

 North America. It has been recorded that during the fall of 1908 

 they were abundant at Winter Harbor, Franklin, and that the last 

 one seen was on September 8. The Kittatinny Ridge in Pennsyl- 

 vania is apparently a good observation post for this species, several 

 having been noted there in the fall of 1934, from October 11 to Novem- 

 ber 2. 



Nothing is known of the return trip to the north. 



Casual records. — There are several widely scattered records of 

 occurrence south of the winter range above outlined. Among these 

 are: Ohio, a specimen from Washington Court House on January 30, 

 1907; North Dakota, one collected at Grafton, on October 7, 1908; 

 South Dakota, one on October 21, 1880, near Vermillion; Kansas, one 

 at Manhattan on December 1, 1880; Wyoming, one noted at Fort 

 McKinney during the winter of 1883-84; and Washington, a specimen 

 collected near Spokane, in December 1896. 



Egg dates. — Greenland: 5 records, May 6 to June 13. 



Arctic America: G records, May 9 to June 12. 



Labrador: 3 records, May 22 to 28. 



FALCO UUSTICOLUS OBSOLETUS Gmelin 



black gyrfalcon 



Plates 1-4 



HABITS 



This, the darkest of all the gyrfalcons, was formerly supposed to be 

 confined to Labrador in the breeding season; but now it is generally 

 conceded to be the dominant American form, breeding all across the 

 northern part of the continent from Labrador to northern Alaska. 

 Lucien M. Turner says in his unpublished notes on the birds of Ungava: 



This species may be considered common, as it is the most abundant hawk in the 

 region. During the excessively cold periods of winter but few are to be seen. 

 About the middle of March they are more numerous, and they become plentiful by 

 the last of April. They evidently retire to the southern portion of the region for 

 the winter. As soon as the warm days of April arrive these birds seek their 

 mates and, from the evidence presented under the remarks on the eggs procured, 

 it would seem that their courtship is of short duration. These hawks have no 

 special preference for any particular portion of the country, whether it be barren 

 or wooded. 



Dr. E. W. Nelson (1887) says of its status in northern Alaska, 

 though some of his notes may refer to uralensis: 



