148 University of California Publications in Zoology [Vol.24 



they should not arrive at the mouth. However, a short distance below 

 the Great Glacier, about at the boundary, the stream turns sharply 

 to the westward. Just above this bend is the mouth of the Iskut, a 

 tributary of the Stikine that is nearly as large as the main stream. At 

 the point of junction the broad valley of the Iskut enters from the 

 southeast and its course is east and west for some distance. A per- 

 fectly feasible outlet is thus afforded for migrating- birds from the 

 northward at just the point where the Stikine Valley would lead 

 them astray. I do not know that this is the course that is actually 

 followed, but it may very well be, and if so it serves to explain the 

 absence at the mouth of the river of species that were migrating south- 

 ward in numbers at a point some thirty miles up stream. 



There are, however, certain inland species that appear to migrate 

 regularly coastward, though doubtless in lesser numbers than go 

 directly south. Dendroica coronata hooveri has been taken in the fall 

 near the mouth of the Taku Eiver (Swarth, 1911, p. 99), and we 

 obtained it at the mouth of the Stikine, each time in sufficient numbers 

 to appear to be of regular occurrence. Sialia cii,rrucoides has been found 

 near the mouth of the Taku under similar circumstances (Swarth, 

 loc cit., p. 112), and while we, ourselves, did not meet with this species 

 at the mouth of the Stikine, specimens have been taken there. 



The question arises as to the migration of such species as Melospiza 

 melodia rufina and Passerella iliaca fuKginosa, coastal forms primarily 

 but breeding far inland up the Stikine. Whether or not they ascend 

 and descend the river in their travels is not clear, and the facts will 

 be difficult to ascertain. 



The casual occurrence at th# mouth of the Stikine in the spring of 

 such species as Myadestes townsendi and Sialio) currucoides (see pp. 

 301, 309) is noteworthy. Such wanderers in the fall might be ex- 

 plained as individuals that had mistakenly followed the river to its 

 mouth. In the spring, they can not be regarded as having gone 

 astray. The fact that they had reached this point is evidence that they 

 were confidently traveling to a definite goal, though along a path not 

 usually followed by their kind. 



At high water, quantities of drift are carried down the river. It 

 is probable that small mammals living in the bottom lands often take 

 refuge in fallen trees or in masses of brush that are suddenly floated 

 away, and are thus transported far down the river. This may be one 

 factor tending toward the more general extension coastward of inland 

 species as compared with the sharper restriction of coastal forms (see 

 fig. Q). 



