1922] Swarth: Birds and Mammals of ihe Stikine Region 301 



of the upper parts in the northern birds is appreciably more gray, less 

 buffy, and the spots are less yellowish. We obtained no adults, but 

 the Wrangell adult, above mentioned, and others from the Eoeky 

 Mountain region farther south are not perceptibly different from the 

 Caiifornian birds. The differences seen in the juvenals may be signifi- 

 cant, but our material is not sufficient to demonstrate the fact. 



Hylocichla ustulata ustulata (Nuttall). Russet-backed Thrush 



There were a very few individuals of this species still lingering in 

 the region when we arrived at the mouth of the Stikine River, about 

 the middle of August. One was seen on Sergief Island, August 18, 

 and another on September 4, both in the alder thickets that surrounded 

 our camp. As neither one was taken, it is, of course, possible that the 

 birds seen were of the subspecies swainsoni, rather than ustulata. Our 

 experience on the Stikine disclosed the presence of swainsoni so far 

 down the river that it would not be surprising if occasional individuals 

 should wander quite to the coast during migration. However, as 

 Sergief Island is within the known range of ustulata, while swainsoni 

 has never yet been taken on the coast, it is proper to refer the records 

 from that point to the race known to occur there. 



Hylocichla ustulata swainsoni (Tschudi). Olive-backed Thrush 



One of the commoner species of the upper Stikine Valley. First 

 noted at the Junction on May 28 ; the next three days saw an influx 

 of considerable numbers. On May 31 the first song was heard, so 

 similar to the, to us, more familiar notes of the russet-backed thrush 

 as to be indistinguishable. On June 5 a female was shot, with eggs 

 beginning to enlarge in the ovary, on June 9 one was taken which 

 had laid part of its set, and on June 12 the first set of eggs was ob- 

 tained. A young bird, just out of the nest, was taken at Glenora on 

 July 7, and full-grown juvenals were collected at Flood Glacier early 

 in August. 



This is a bird of the poplar woods and willow thickets of the low- 

 lands, primarily, but we found it also in small numbers well up the 

 mountain sides. On July 17 Dixon saw several at the upper edge of 

 the spruce timber (about 4000 feet) on the mountains above Doch-da-on 

 Creek. 



Nests found were all at the lower levels. The first discovered was 

 in fairly open woods, mostly of small willows, and in a very exposed 



