1921 BIRDS OP MONTANA 133 



about Bozemaii (SaundiTs, IDlla, p. 44); coiuiuon in Jefferson, Powell, Dcoi 

 Lodge and Silver Bow counties (Saunders, 1912a, p. 29) : rare in Teton and 

 Lewis and Clark counties (Saunders, 1914a, p. 189) ; one at Lake Como, Au^Mist 

 :', 1911 (Bailey, MS). I have also seen this species commonly along the inoun^ 

 tain streams of western Park County and have noted it in Glacier National Park, 

 in willow thickets at the outlet of Gnn.sight Lake, at Summit on the Great North- 

 ern Railroad, and along the trail between Iceberg and McDerniott lakes. 



The spring arrival on the breeding grounds takes place in A|)i'il. l)at(s 

 are: Bozeman, April 9, 1909, and April 2, 1911 ; Divide Creek. Silvt i- P.ow Conn- 

 ty, April 11, 1911). The fall migration is not so easily determined. Tiie hitest 

 date I have is from Gold Creek, Powell ( ounty, August 27, 1910, but 1 believe 

 the species remains later than this. 



The nesting has not been recoi'iled fr-oiu this state. .Mi'. G, 1>. Thomas has 

 informed me that he has found nests containing both eggs ami young near Boze- 

 man, but exact dates are lacking. The abundance of this spei'ies in I he breeding 

 season seems to have been overlooked by most observers, due to the fact that the 

 birds inhabit the most impenetrable willow thickets, and are very difficult to 

 observe. During the spring they are conspicuous because of the loud, ch'ar 

 song, which may be heard from the first arrival in April until early m July. 

 After that date the birds are very hard to find. The work of most obsei-vers in 

 westei-n ^Montana has been confined to the summer, after this species has eeaseil 

 to sing, which accounts foi- thi'ir not finding it in regions where it is eoninion. 



252. Pipilo maculatus arcticus (Swainson) 



Akctic Towhee 



A sunnner resident throughout the state, eomiiioa in most localities. Per- 

 haps not found in extreme northeastern .Montana, and rare in sotne places west 

 of the divide. Breeds in the Transition zone, in thickets of willow, wild I'o.se 

 and other shrubs. Recorded by all obsei'vers tlirough the eastern part of the 

 .state, and in the mountainous part east of the divide, but there are only a few 

 records west of the divide. It is not recorded from the Bitterroot Valley, and I 

 have no note of its occurrence in the vicinity of Jlis.soula. At Flathead Lake 

 it is common about Big Fork and I'are at YcJlow Bay. In Deer Lodge, Jefferson, 

 Silver Bow and Powell counties I noted it but once, in the course of two years 

 observation, then only in spring migration and not breeding. It is quite prob- 

 able that the few birds that do breed west of the divide belong to a more west- 

 ern race than arctic lift. 



Migrations take iilace in .May and September. F]iglit years at Terry giv.- 

 May 10 for the average, and May 2, 1894, the earliest. Eight years at Great 

 Falls average May 11, with May 6, 1904, the earliest (Cooke, 1912. \k 2,S9). 

 Other dates are: Lewistown, May 2, 1900, and May 4, 1901 (Silloway. 190;3a, p. 

 58) ; East Gallatin River, May 12, 1909; Anaconda, April 15, 1911 ; and Chotean, 

 May 12, 1912. Fall departures in northern Montana average September 24, with 

 October 9, 1905, the latest (Cooke, 1912, p. 290). Another fall date is from 

 Bozeman, September Vi. 1908. 



