1922] Swarth: Birds and Mammals of the Stikine Region 2S9 



of course, were migrants, and the assumption is that those individuals 

 of intermediate character that were taken at the same time were also 

 migrating birds, presumably from some intermediate region near the 

 northern limit of the habitat of rufina. Our experience on the upper 

 Stikine leads me to believe that very young birds, even before the 

 Juvenal plumage is discarded, may wander many miles from the nest- 

 ing ground. 



Melospiza melodia caurina Ridgway. Yakutat Song Sparrow 



A fairly common migrant at Sergief Island, amid the same sur- 

 roundings as rufina. One was seen the day of our arrival, August 17, 

 and the birds were present in fluctuating numbers up to the date of 

 our departure, September 7. The third week of August was the time 

 of greatest abundance. , Usually caurina and rufina could be told apart 

 in life, the greater size and grayer color of the former serving to dis- 

 tinguish it ordinarily. There are, of course, equivocal specimens, as 

 mentioned in this report under rufina, that are practically intermediate 

 between the two subspecies, and difficult of determination even when 

 in hand. There are also in the series of caurina from Sergief Island 

 some specimens closely approaching the larger kenaiensis in appear- 

 ance. As, however, the latter reach only the minimum measurements 

 of that subspecies it seems best to place them all under caurina. There 

 is thus in the available series of caurina a considerable range of varia- 

 tion exemplified, from small, reddish colored birds not widely different 

 from rufina, to large, gray colored ones that could be inserted in a 

 series of kenaiensis without violence. 



There is one bird from Sergief Island (no. 40045, female, August 

 18) that I refer to caurina despite the fact that it is largely in juvenal 

 plumage and was collected in the breeding range of rufina. Such of 

 the first winter plumage as has been acquired is distinctly of the 

 caurina type, and in the flesh the bulk of this bird was decidedly 

 greater than that of the average rufina. Despite the youth of this 

 individual, I believe it to be a migrant from the distant habitat of 

 caurina. Juvenals of rufina also were found traveling far from the 

 nesting ground. 



Fourteen specimens of Melospiza m. caurina were taken at Sergief 

 Island, on dates ranging from August 18 to September 5 (nos. 40045, 

 40046, 40066-40077). The series comprises one adult male, one adult 

 female, five immature males, six immature females, and the juvenal 

 female above described. 



