1-42 
TIIIv COXDOR 
Vol. XVI 
Oporornis tolmiei. MacGillivray Warbler. Common summer resident of 
willow and wild-rose thickets in the foothills and lower mountains, up to 5000 
feet. Occurs in the prairies in migrations. Migration date : May 23, 1912. 
Geothlypis trichas occidentalis. Western Yellowthroat. Common sum- 
mer resident of the prairie region and foothills, usually in willow thickets. On 
1 he prairies I have also heard the birds singing in the rushes on the borders of 
sloughs, and believe that they nest there. Migration date May 19, 1912. 
Wilsonia pusilla pileolata. Pileolated Warbler. Common summer resi- 
dent of willow thickets in the mountains, from the foothills to 6000 feet. Com- 
mon migrant in the prairie region. Observed in migration at Choteau, ]\Iay 
22-28, 1912, and on the Sun Eiver August 26-28, 1911. 
Setophaga ruticilla. Redstart. Summer resident of the willow thickets 
along the foothills and in the lower mountain canyons i;p to 5500 feet. Much 
more common as a migrant, when it also occurs in the prairie region. Ob- 
served in migration at Choteau, May 22-28, 1912. 
Anthus rubescens. Pipit. Migrant in the prairie region. Occurs in large 
flocks with horned larks and McCown Longspurs, and feeds about the borders 
of alkaline ponds. Migration dates: September 17 to October 1, 1911. 
Anthus spraguei. Sprague Pipit. Common summer resident of the prai- 
ries. Appears to prefer neither the dry prairie benches, nor the rich grass 
meadows, but occurs about the borders of ponds, or in hollow depressions in 
the prairie where the soil is moist, hut too alkaline to he clothed with a tall 
thick growth of grasses. The bird itself is very difficult to see and observe, 
blit the song is one of the commonest sounds on certain parts of the prairies in 
June and July. Migration date : May 23, 1912. 
Cinclus mexicanus unicolor. Dipper. Permanent resident on mountain 
streams. Occurs in the vicinity of waterfalls in summer, but winters in places 
Avhere the fall of the stream is not so steep, and yet Avhere the current is SAvift 
enough to keep open AAmter all Avinter. Begins nesting late in May. 
Dumetella carolinensis. Catbird. Common summer resident in AvilloAv 
thickets on the prairies, and, along the foothills of the mountains, in thickets 
of Avild-rose. Migration date : May 23, 1912. 
Salpinctes obsoletus obsoletus. Rock Wren. Summer resident. Occurs 
in rocks about the edges of prairie buttes, and in the loAver mountain canyons 
up to 5000 feet. Rather rare. Migration date: May 27, 1912. 
Troglodytes aedon parkmani. Western House Wren. Common summer 
resident of the prairies, nesting about buildings and in dead stumps in cotton- 
Avood groves. Migration date : May 19, 1912. 
Nannus hiemalis pacificus. Western Winter Wren. Rare summer resi- 
dent of spruce forests in the mountains. A pair, Avith brood of young, Avere 
observed on BeaA^er Creek, in the Sun River countrA^ on June 29, 1911. A sin- 
gle bird observed on Birch Creek, May 31, 1912. 
Certhia familiaris montana. Rocky Mountain Creeper. Occurs rarely in 
spruce forests in the mountains. All my records are from about the head- 
Avaters of the Sun RiA^er, and are betAveen August 29 and September 8, so I am 
doubtful if the species is more than a migrant here. 
Sitta carolinensis nelsoni. Rocky IMountain Nuthatch. Summer resident 
in the mountains. Occurs in Lodgepole Pine and Douglas Fir forests in the 
Canadian zone, and in White-bark Pine forests in the Hudsonian zone. 
Sitta canadensis. Red-breasted Nuthatch. Migrant. Common in the 
