GREEN, GREENISH GRAY, AND OLIVE 453 
times seeming, by their whiteness, to be fruit worms. 
The intervals between feeding are unusually short, rang- 
ing from three minutes to half an hour. | 
633.1. LEAST VIREO. — Vireo pusillus. 
Famity : The Vireos. 
Length: 4.80-5.25. 
Adults: Upper parts plain gray, tinged with olive-green on rump, wings, 
and tail; wings with one or two narrow bars ; lores gray and white ; 
under parts white ; sides tinged with olive-gray and pale yellow. 
Young: Lores entirely white ; top of head and hind-neck pale brown ; 
back dull green. 
Geographical Distribution : Southern and Central California, Lower Cali- 
fornia, and Arizona. 
California Breeding Range: Northern San Joaquin-Sacramento valley 
to Sacramento. 
Breeding Season: April and May. 
Nest: In bushes and thickets ; made similar to that of the other vireos. 
Eggs: 3 or 4; lightly dotted with brown, especially at the larger end. 
Size 0.69 X 0.48. 
THE Least Vireo is a bird of the warm valleys and 
foot-hills, frequenting the alder thickets along the wet 
bottom lands and following the spring into the foot-hills 
or more northern valleys to nest. It is a tiny mite in 
grayish green, and scarcely distinguishable from the 
foliage as it hunts through the bush for insects. Its 
semi-pensile nest is fastened to the slender twigs of the 
willows as close to water as it can get. This is not 
because of its fondness for bathing, but because of the 
‘abundant insect life found in wet places. While not 
a great musician, the Least Vireo calls enthusiastically 
early and late from the cover of the bushes, showing at 
times decidedly imitative qualities not possessed by any 
of its family except the white-eyed vireo. 
