May, 1914 
BIRDS OF NORTHERN IMONTANA 
141 
1911 (Condor, xiv, 1912, p. 30), but I now believe that the birds seen by me 
in Gallatin County in May (Auk, xxviii, 1911, p. 46), also belong to this 
subspecies. 
Vireosylva olivacea. Ked-eyed Vireo. Summer resident in the j^rairie 
region, nesting in cottonwood groves. Rare north of the Sun River and not 
very common there. 
Vireosylva gilva swainsoni. Western Warbling Vireo. Common summer 
resident in aspen groves in the mountains up to about 5500 feet. Most abun- 
dant along the foothills. Pound all summer in cottonwoods in the prairies, 
but in small numbers. 
Lanivireo solitarius cassini. Cassin Vireo. Observed on the West Pork 
of the Sun River, at an altitude of about 5500 feet, on September 3, 1912. 
Vermivora celata celata. Orange-crowned Warbler. Common summer 
Fig. 47. Nest and eggs of McCown Longspur. 
resident of aspen groves in the mountains from the lower foothills to about 
6000 feet. 
Dendroica aestiva aestiva. Yellow Warbler. Abundant summer resident 
of cottonwood groves and willow thickets in the prairie region. Migration 
dates: May 22, 1912, August 18, 1911. Nesting begins early in June and 
young are on the wing about the first Aveek in July. 
Dendroica auduboni auduboni. Audubon Warbler. Common summer 
resident of evergreen forests in the mountains, occuring throughout the Can- 
adian zone. 
Dendroica striata. Blackpoll Warbler. Common migrant in cottonwood 
groves in the prairie region. Observed near Choteau in considerable numbers 
May 22 to 25, 1912. This region is probably at about the Avestern limit of the 
migration range of this species in Montana. 
