546 LAND BIRDS 



known concerning the nesting habits of this species, so 

 far as the time of incubation and the rearing of the 

 young are concerned. One nest, found near San Jos^, 

 June 2, and containing young about six days old, was 

 visited daily with no disastrous results, but this is only 

 a partial success among a long list of failures. In this 

 case the parents were so shy that they refused to go to 

 the nest with food while an observer was in sight, and 

 the field glasses could reveal nothing sufficiently accurate 

 to be recorded. The nest was nicely hidden in a clump 

 of weeds on the edge of a small brook and within five 

 inches of the ground. A jump across the brook almost 

 into it resulted in its discovery. When watched, the 

 adults alighted at some distance from it and dodged 

 from clump to clump and through the weeds until they 

 reached the spot where it lay. Close observation failed 

 to record accurately how often they went with food, so 

 slyly did they slip through tangles and open like small 

 gray mice ; the crops of the nestlings, examined immedi- 

 ately after feeding, bulged with insect food dark in color. 

 They left the nest after four days' watching, and were 

 probably less than ten days old. 



681c. PACIFIC YELL6 W-THRO AT. — Geothlypis 

 trichas arizela. 



Family : The Wood Warblers. 



Length: 4.70-5.75. 



Adult Male : Forehead and sides of head black, bordered above with 

 white, sometimes tinged with yellow ; rest of upper parts plain olive- 

 green ; under parts yellow. In winter washed with brown. 



Adult Female : Upper parts olive-brown, without black, ashy, or white ; 



