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. — Fireo belli pusillus. 

 Family : 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 Distrihutio^i : 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 ch)se 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 tlie bushes, showing at 

 times decidedly imitative qualities not possessed by any 

 of its family except the white-eyed vireo. 



