LINES OF MIGRATORY FLIGHT 145 



breeding stations from twenty to one hundred miles 

 from the point where the Stikine debouches into the 

 Pacific. In the valley of the Skeena River, two hun- 

 dred miles south of the Stikine, the catbird, king- 

 bird, and red^eyed vireo, all eastern forms, penetrate 

 to within one hundred and eighty miles of the sea. 

 In normal migration these retrace their route across 

 the mountains and move south along the broad in- 

 terior flight lines. 



In considering North America as a whole, we must 

 mention also two important terminals, one on the 

 northeast and the other on the northwest, where 

 a few extralimital birds come to our shores to breed 

 and then in fall return to Old World wintering 

 grounds. In Ellesmere Land and Greenland, for 

 example, we find the wheatear breeding regularly; 

 and J. C. Phillips, reasoning from the many records 

 of the European widgeon in the eastern United 

 States, is inclined to believe that this duck has a 

 breeding colony in Greenland. 



In western Alaska Kennicott's willow warbler and 

 the Alaskan yellow wagtail nest each summer, and 

 then return westward, to migrate south through 

 eastern Asia, while the European teal (Nettion 

 creccd) crosses to breed in the Aleutian Islands, but 

 is not known to reach the mainland. The Old World 

 warbler and the wagtail mentioned have had their 

 Alaskan colonies so long established that birds from 



