May, 1914 
BIRDS OF XORTHERX MONTANA 
143 
mountains in late August and early September. Rare on the prairies, where I 
observed it near Choteau, May 25, 1912. 
Penthestes atricapillus septentrionalis. Long-tailed Chickadee. Common 
permanent resident of willow thickets in the prairie region, and in the lower 
mountain canyons up to 5000 feet. 
Penthestes gambeli gambeli. Mountain Chickadee. Common permanent 
resident of pine and fir forests in the mountains. 
Penthestes hudsonicus hudsonicus. Hudsonian Chickadee. Probably a 
rare permanent resident of spruce forests in the mountains. I observed it but 
once, when I found a pair, accompanied by six nearly full-grown young, in a 
dense spruce thicket on the South Fork of the Teton River, at an altitude of 
6000 feet. 
Regulus satrapa olivaceus. Western Golden-crowned Kinglet. Common 
summer resident of spruce forests 
in the mountains. 
Regulus calendula calendula. 
Ruby-crowned Kinglet. Common 
summer resident of fir forests in 
the mountains. Migrant in Avil- 
loAV thickets in the prairies, Avhere 
I observed it, near Choteau, May 
25, 1912. 
Myadestes townsendi. Town- 
send Solitaire. Common summer 
resident about steep cliffs and 
rocky ridges in the mountains. 
Hylocichla fuscescens salici- 
cola. Willow Thrush. Summer 
resident of AvilloAV thickets in the 
prairies. Most abundant along 
the foothills in the mountains. 
Common in LeAvis and Clark 
County, but becoming rare north- 
Avard in Teton County. 
Hylocichla ustulata swainsoni. 
Olive-backed Thrush. Abundant 
summer resident in the moun- 
tains, and abundant migrant in cottonwood groves on the prairies. Migra- 
tion dates: May 22, 1912, August 21, 1911, and September 4, 1912. The latter 
tAA’o dates are from the mountains about the headAvaters of the Sun River. 
Hylocichla guttata auduboni. Audubon Hermit Thrush. Rare migrant. 
1 observed it near Choteau, May 18 and 23, 1912, and on the West Pork of the 
Sun River, September 12, 1912. Have not observed it here in summer in the 
mountains, as I have in southern Montana. 
Planesticus migratorius propinquus. Western Robin. Abundant sum- 
mer resident in cottonAvood groves in the prairies, and in pine and fir forests 
in the mountains up to 5500 feet. Migration dates : March 28, 1912, and Octo- 
ber 29, 1911. Begins nesting in the latter part of May. The eggs take about 
fourteen, days to hatch, and the young leave the nest in about ten or eleven 
days more, so that young are seen on the AAung by the middle of June. The 
