BREWER- S SPARROW 1213 



They seemed to be spending most of the forenoon hours every day in 

 the mesquites along the overflow ditches, thoroughly wetting the 

 plumage in the shallow streamlets and then perching in the green 

 canopied branch-work above to preen at great length. Sometimes such 

 bathmg parties would be perfectly quiet save for the sound of fluttering 

 wings. Then again some certam individual would break into pro- 

 longed singing * * *. Occasionally many, occupying adjacent mes- 

 quite thickets, would sing ecstatically in chorus, giving an effect of the 

 bedlam of canary songs one hears in a bird store." 



Once on the breeding grounds, however, these sparrows become 

 quite inconspicuous, ducking into bushes at the least provocation and 

 keeping warily close to shelter when feeding on the ground. Flock 

 activities cease, except for communal singing, and loosely defined 

 territories are set up, with singing males occupying some regular 

 vantage point, usually on the end of a branch in the vicinity of the 

 nest. Few data are available on territory size or the extent to which 

 these may be defended. L. Wing (1949) indicates that there may be 

 as many as 47 breeding pairs per 100 acres in eastern Washington. 



The timberline sparrow behaves similarly. H. S. Swarth (1930) 

 ^^Tites: "It was evident that singing males were occupiyng perches in 

 fairly close proximity, a bird, perhaps, to every five or six acres, where 

 conditions were favorable. They were wary, and generally flew 

 before they could be closely approached, but always moved about 

 within a rather short radius, unuilhng to be driven far afield. For 

 each singing male it seemed Hkely that there was a mate upon a nest 

 near by * * *." 



It does not seem to be known whether natal care is by the female 

 alone or by both parents, and I find nothing in the Hterature on the 

 behavior of a parent towards its offspring, 



W. P. Taylor (1912) describes the flight pattern of hreweri on its 

 northern Nevada breeding groimds: "The birds made rather nervous 

 movements, often flying irregularly into the air to a height of fifteen 

 feet or more and then shooting straight down and coming to rest in a 

 sagebrush. Certain variations in flight were observed. For instance, 

 at times a manner of movement resembHng that of a vesper sparrow 

 was noted, the Brewer flying in a zigzag manner towards a bush at 

 some distance and sinking to the ground behind it, repeating the 

 operation on being flushed again." The timberline sparrow acts in 

 the same manner when flushed from the top of one of the balsam 

 thickets on which it perches when suspicious of danger. H. S. 

 Swarth (1926), impressed by the wariness of these sparrows, writes 

 that when flushed they fly long distances and then dive into birch 

 thickets. He found it difficult to dislodge and follow a bird from such 



