448 LAND BIRDS 
to understand and translate into human speech. Mrs. 
Eckstrom says: “ Few birds are easier to tell by their 
music and harder to tell without it than the Vireos. By 
all means put their song into words.” The song of the 
Warbling Vireo is a quaint, cheery melody whistled all 
day long until chill autumn rains drive him to a warmer 
climate. He is a mountain-lover, choosing the aspens 
and oaks of the Sierra Nevada rather than the lowland 
thickets. If he condescends to build in a city park, his 
nest will swing as near the top of the tallest tree as he 
can find suitable twigs to hold it. Usually it will be at 
the edge of a stream or near an open space. In the fall 
this bird becomes very friendly, coming into the orchards 
and gardens to hunt busily among the leaves for small 
caterpillars. At this time he is fond of the cornel ber- 
ries that grow along mountain brooks, and occasionally 
condescends to eat mistletoe, though he prefers insect 
food. 
629 a. CASSIN VIREO. — Vireo ‘solitarius cassinit. 
Famity: The Vireos. 
Length: 5.00-5.60. 
Adults: Top and sides of head dark gray, blending to white on the 
throat ; clearly defined white eye-ring and loral streaks; back dull 
olive-green ; wings with two clear white bands; under parts clear 
white, tinged with yellow and olive on sides and flanks. 
Young: Upper parts dull grayish brown ; under parts dull buffy. 
Geographical Distribution: Western United States, chiefly on the Pacific 
coast in summer ; east to New Mexico, and south to Mexico in winter. 
California Breeding Range: Along the Sierra Nevada. 
Breeding Season: May, June, and July. 
