112 
the Condor 
Vol. XVII 
few years ago by Mr. Silloway and noted in an unpublished manuscript of his 
now in the possession of Dr. Elrod. It is another bird that is probably increas- 
ing in numbers due to the increasing areas of cut-over land. 
The west shore of Flathead Lake is in general quite different in character 
from the east shore. The soil is evidently drier and the rainfall is probably 
considerably less. The forests are largely confined to slopes of east and north 
exposure, while the other slopes are clothed only with open grass land. These 
forests are composed almost entirely of yellow pine, the other trees, such as 
Douglas fir, western larch and Engelmann spruce, being confined to a few 
scattered individuals. The bird life of the two shores consequently differs 
considerably, such species 
as the Audubon and Town- 
send warblers, the King- 
lets and the Olive-hacked 
Thrush, that are common on 
the east shore, being almost 
lacking here, while in the 
open pine forests Western 
Wood Pewees are the com- 
monest birds, and in the 
grass lands Western Mea- 
dowlarks and Western Ves- 
per Sparrows are abundant, 
all of these species being 
rare or local on the east side 
of the lake. 
These conditions are found 
well illustrated on Wild 
Horse Island, the largest isl- 
and in the lake. This island is 
near the west shore and al- 
most directly across the lake 
from Yellow Bay. Here, on 
July 2, two more birds new 
to Flathead Lake were 
found. The first of these was 
the Pygmy Nuthatch ( Sitta 
pygmaea pygmaea ) . I observ- 
ed and later secured a sin- 
gle bird of this species in 
the pines, and Dr. Elrod saw three more on another side of the island. The 
other new bird was the Prairie Falcon ( Falco mexicanus), a male of which 
flew low over my head as I was adjusting my camera to take some pictures 
from the top of a high rocky hill on the west end of the island. 
The mountains of the Mission Range nearest to Yellow Bay are rather low 
in elevation. Their sides have been burned repeatedly by forest fires, so that 
down timber, brush and thickets of young lodgepole pine make climbing very 
difficult. A trip made to the top of one of the peaks on July 16 was rather 
disappointing in the number of birds found. As we ascended the mountain 
most of the species found about the lake shore disappeared, while few of the 
Fig. 42. Canyon of the Pend d’Oreille River, 
Montana; nesting ground of the Violet-green 
Swallow 
