324 REPORT OF BERING SEA COMMISSION. 



Pribiiof andence Under diverse physiographic conditions 



Comni.'iuder herds 



do not miugie. would dcstroy all specific characters.* 

 L-itterence of The pelasTe of the Pribiiof fur-seals differs so 



pelage oi Alaskan ^ ^ 



and Russian iur- markedly from that of the Commander Islands 

 fur-seals that the two are readily distinguished 

 by experts, and have very different values, the 

 former commanding much higher prices than the 

 latter at the regular London sales. 

 Extent of migra- 4 rpj^^ ^j^ breeding malcs of the Pribiiof herd 



tion. ~ 



are not known to range much south of the Aleu- 

 tian Islands, but the females and young appear 

 along the American coast as far south as north- 

 ern California. Returning, the herds of females 



CouTSO of north- , , , , r /~\ 



ward migration, movc iiorthward aloiig the coasts 01 Oregon, 

 Washington, and British Columbia in January, 

 February, and March, occurring at varying dis- 

 tances from shore. Following the Alaska coast 

 northward and westward they leave the North 

 Pacific Ocean in June, traverse the eastern passes 

 in the Aleutian chain, and proceed at once to the 

 Pribiiof Islands. 



* The home of a species is the area over which it breeds. It is 

 well known to naturalists that migratory animals, whether mam- 

 mals, birds, fishes, or memljers of other groups, leave their homes 

 for a part of the year because the climatic conditions or the food 

 supply become unsuited to their needs ; and that wherever the 

 home of a species is so situated as to provide a suitable climate 

 and food supply throughout the year such species do not migrate 

 This is the explanation of the fact that the Northern fur-seals are 

 migrants, while the fur-seals of tropical and Avarm temperate lati- 

 tudes do not migrate. 



