1926] Swarth: Birds and Mammals from the Atlin Region 119 



at 3500 feet on Otter Creek, July 30, and a male in juvenal plumage 

 at the base of Monarch Mountain, August 17, the last date of record. 

 The Wright flycatcher was of decidedly rare occurrence, not more 

 than six or eight indi\dduals, all told, being seen during the summer. 

 Breeding birds were taken at a higher altitude than that at which 

 hammondu occurs. 



Otocoris alpestris arcticola Oberholser. Pallid Horned Lark 



Breeds in fair abundance throughout the open country on the 

 ridges above timber line. On June 19, young out of the nest were 

 seen. During the last week in July and the first week in August, old 

 and young were in the midst of the molt; two adult males collected 

 on August 7 and 8, respectively, have nearly completed the change. 

 During this season of molt, the horned larks were generally found 

 either as single birds or two or three together, but before the end of 

 August they were gathered in flocks of from fifty to one hundred 

 individuals. 



Fourteen specimens were collected (nos. 44769-44782), three in 

 juvenal plumage, three adults in worn breeding plumage, and one 

 immature and seven adults in more or less completely acquired winter 

 plumage. The species was last seen on August 24, though later trips 

 were made to the high altitudes where it occurs. 



Pica pica hudsonia (Sabine). American Magpie 



Several pairs were seen near Carcross during the last week in May, 

 and two nests found, occupied but without eggs. None was seen about 

 Atlin during the early part of our stay, and we were told that magpies 

 did not nest in that section but that the birds did appear there at the 

 very end of the summer. I saw several at Gladys Lake, September 8. 

 On September 19 one appeared at Atlin, and I saw the species each 

 day until the 23rd, when I left. 



The late summer invasion of the Atlin region by the magpie is 

 probably related to the migration of this species to the coast of south- 

 eastern Alaska, as observed by me on the lower Taku River in 

 September, 1909 (Swarth, 1911, p. 77). The valley of the Taku, lying 

 southwest of Lake Atlin, is a natural outlet from this region to the 

 coast, and the magpies I saw there were, together with other species, 

 migrating down this valley from the interior. 



