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BULLETIN 16 7, UNITED STATES NATIONAL MUSEUM 



many are birds of Scandinavian origin. The figures in table 1 are 

 taken from Schi0]er's work and show that on size alone the West 

 Greenland sea eagle {HcHiaeetus dlhiciJla groenlnTidimis Brehm) 

 deserves subspecific rank: 



Tabt-E 1. — Average measurements {in millimeters) of SI young and 26 adult 

 skins of Haliaeetus albicilla groenlandicus and 12 young and h adult of H. a. 

 albicilla, from Scandinavia and Denmark. {After 8chi0ler, 1931) 



Although individual variation in this species is considerable, there 

 is little doubt that when sufficient material for comparison is available, 

 some further subdivision will be necessary. Of the American rec- 

 ords the Cumberland Sound birds probably belonged to the Green- 

 land race ; the Nantucket bird was immature and probably was also 

 of this form, though it is within the bounds of possibility that it was 

 a straggler from Iceland, where H. a. albicilla breeds. The Unalaska 

 specimen, however, must belong to the form that breeds in north- 

 eastern Asia. According to A. H. Clark (1910) and Dr. H. C. 

 Oberholser (1919) this race is so much smaller than the typical form 

 that it deserves recognition, and the latter writer suggests that 

 Hume's name, H. a. hrooJcsi, can be used for it, though applied to a 

 winter bird in North India. 



/Spring. — In the case of such a widely distributed species, ranging 

 as it does over practically the whole of the Palearctic region, the 

 habits must necessarily vary according to the locality. Thus, even 

 in the case of the Greenland sea eagle, the birds that breed in the 

 north are perforce migratory, moving southward on the approach 

 of winter, when their hunting grounds are frozen over, while in 

 southern Greenland, where the warm current keeps the coast more or 

 less open, they are sedentary, working their way northward along the 

 coast in spring. Except in the far north, the adults remain all the 

 year round in the neighborhood of their nests. Immature birds that 

 winter on the Schleswig coast generally leave about the end of 

 February for the north. 



Courtship. — There seems to be little doubt that this eagle pairs 

 for life, as the same birds may be seen in one district for j^ears. 

 When one of the pair is killed, the survivor, if it be the breeding season, 

 obtains a fresh partner within a few days. Dr. H. L. Saxby (1874) 



