GREEN, GREENISH GRAY, AND OLIVE 437 



Nevada in California. Throughout this extensive range 

 the breeding season occurs some time between the first 

 of May and the last week in July ; and within that 

 period each pair sometimes, but not usually, raises two 

 broods. My own observations lead me to believe that 

 in the same^ zone there is, in the case of all birds, a 

 difference of about five days in nesting for every degree 

 of latitude. This would make the season north of San 

 Francisco from three to four weeks later than in the 

 San Diegan district. 



The Western Flycatcher is even less restricted in his 

 selection of a building site than in choice of climate. 

 On the ground among the roots of trees, up high on a 

 tree branch, in the bottom of a deserted flicker's hole, on 

 a ledge of rock, he seems to follow no law but his own 

 sweet will or that of his wee mate. 



The notes on this Flycatcher by Mr. Charles A. Allen, 

 of Nicasio, California, seem to me well worth quoting. 

 He says : " It is a very widely' distributed species 

 throughout this part of the State, both among the forests 

 on the highest hills, where there is not a drop of water 

 for long distances, and along the banks of brooks and 

 streams in the lowlands ; I have found its nests in all 

 sorts of situations, — sometimes in a small tree, placed 

 in the upright forks of the main stem ; again, on the 

 side of the stem where a small stub of a limb or some 

 sprouts grew out ; or in a cavity in a tree trunk ; against 

 an old stump, or a root which had been washed down 

 during a flood in the middle of a stream ; among curled- 

 1 See map of life zones, p. xvi. 



