1911] Swarth: Alaska Expedition of 1909. 159 



Still another group is composed of a few species, which, 

 finding their northern limit at about this latitude in the interior, 

 have apparently followed one or two of the broad river valleys 

 to the coast. Examples of these, already treated in detail, are 

 Geothlypis trichas occidentalis, Empidonax trailU alnorum, 

 and possibly Piranga ludoviciana. 



Judging from our experience the islands of the Sitkan district 

 do not lie in the main migration route of the birds of the Pacific 

 coast. This is true of the western part of the archipelago to a 

 striking degree. During April and May, and in the first week 

 in June, when the migration should have been in full force, we 

 were visiting the western islands, and, though in some places we 

 found vast numbers of waders and many ducks and geese, the 

 smaller land birds were almost entirely absent. In one or two 

 places, noticeably on Coronation and Warren islands, small flocks 

 of migrating warblers or sparrows were met with from time to 

 time; but we visited numerous other points where it was quite 

 possible to spend several hours in the woods without seeing a 

 single small bird ; and when the stillness was broken it was more 

 apt to be by a chickadee or junco than by any transient. I found 

 the west coast of Dall Island to be unusually barren of bird life. 



Possibly the migrants travel more along the inner, sheltered 

 islands. On the east coast of Mitkof Island, in August, there was 

 a steady stream of migrating warblers, kinglets, and other small 

 birds following the shore line southward. At Thomas Bay on the 

 mainland, also in August, migrants were much in evidence. 



The numerous water fowl of the Sitkan district are for the 

 most part species of wide distribution. The sea birds are, with 

 one or two exceptions, of quite general distribution in the North 

 Pacific ; the fresh water species are numerous during the migra- 

 tions, but comparatively few seem to find congenial breeding 

 grounds in this region. They also are mostly of general distri- 

 bution in North America. There are two exceptions, however, 

 a goose (Branta canadensis occidentalis) and a heron {Ardea 

 herodias fannini), which are restricted to the northwestern coast 

 region. 



Museum of Vertebrate Zoology, University of California, 

 BerTceley, June 8, 1910. 



