1924] Swarth: Birds and Mammals of the Skeena River Region 365 



Wilsonia pusilla pileolata (Pallas). Pileolated Warbler 



On May 26 and 27 (our first days at Hazelton), pileolated warblers 

 were migrating abundantly through that region. They then abruptly 

 disappeared, one shot on May 30 being the only other one seen in the 

 spring, and were not found breeding anywhere in the lowlands. An 

 adult male shot near the summit of Nine-mile Mountain, July 30, was 

 just beginning the annual molt. It was one of two birds seen together, 

 perhaps a mated pair nesting there. An immature laale taken at the 

 same place August 11 was in first winter plumage throughout, and 

 may have been a migrant. The three were the only birds of this 

 species seen upon the mountain. 



The first migrant appeared in Kispiox Valley on August 19. 

 Pileolated warblers were then fairly common until the first week in 

 September; the last was seen September 11. Six specimens in all 

 collected (nos. 42528-42533) : two adult (summer) males, one adult 

 male in fresh fall plumage, and three immature males. 



Setophaga ruticilla (Linnaeus). American Eedstart 



Abundant in the lowlands. Present when we reached Hazelton, 

 May 26, and in increasing numbers during the next few days. Several 

 nests were found in Kispiox Valley late in June and early in July, 

 all very similar in structure and location. The usual site was an 

 upright fork of willow or alder, from eight to fifteen feet from the 

 ground. The supporting branches were generally so large as nearly 

 to conceal the tiny nest, or else to make it appear as part of the fork. 

 Nests were in exposed situations more often than in thick shrubbery, 

 sometimes in dead branches, but nevertheless, because of this peculiar- 

 ity of construction, they were not easy to see. One nest collected (no. 

 1857, Kispiox Valley, June 27) contained four eggs; others examined 

 held either two eggs or two young birds. 



Redstarts remained in fair abundance until the end of August ; the 

 last was seen September 8. Unlike some species, of which the adults 

 leave ahead of the young, sometimes before the molt, the adult red- 

 starts seemed to linger quite as late as the juveniles. The adult males, 

 of course, are readily distinguishable, contrary to the rule covering 

 most small birds in the fall, and the number that were seen justifies 

 the statement. An adult female was collected August 29, an adult 

 male September 7. Thirteen specimens in all taken (nos. 42534- 

 42546). 



