ASHY RUFOUS-CROWNED SPARROW 953 



The male rufous-crowned sparrow often sings for some time from 

 perches ^\'ithin the canopy of low shrubs, but when undisturbed for 

 long periods, and especially early in the day, may select a perch on 

 the very top of a bush for his announcements. Even then, however, 

 it is often not the tallest bush of the vicinity. The use of a tree 

 canopy as a song perch, as noted by William L. Dawson, is rather 

 exceptional. 



The main season of advertising song in the San Gabriel Mountains 

 extends from late March into July. A few birds were noted in song 

 as early as February, and singing seems to increase in persistence from 

 mid-April through mid-May. In Griffith Park, Los Angeles, 1 found 

 one rufous-crown giving a full song repeatedly Dec. 27, 1945, the only 

 instance I know of fall or mnter singing. 



Enemies. — No doubt the destruction of much of the original 

 coastal scrub vegetation, to which A. r. canescens is partial, by the 

 mushrooming urbanization of southern California has greatly reduced 

 the populations of this race. Little is on record of other agents of 

 mortality, except that a number of the nests found have been later 

 discovered robbed or abandoned, as is common among many small 

 birds. Mrs. Myers (1909) attributed such loss of the brood of 

 young she was watching to "a skulking feline." The lists of host 

 species of the browm-headed cowbird contains no record of Aimophila 

 ruficeps serving in this capacity, although probably it does so occa- 

 sionally. 



Fall and winter. — Information on activities of these resident birds 

 through most of the hot late summer postbreeding period is lacking. 

 On the one round of visits I made to my San Gabriel Mountains plots 

 at that season, Aug. 31 to Sept. 3, 1951, individuals or pairs were 

 present in or near most of the 12 territories mapped the previous 

 spring. The "skitter" calls described under Courtship, were heard in 

 aU three plots, once coming from a group of four birds apparently 

 made up of two pairs or potential pairs in conflict. No songs were 

 heard at this season, nor on a round of visits to these same plots in 

 late December 1951. At this winter period the birds w^ere much 

 more silent; I heard only the dew and tssp calls, and these in only five 

 territories. I heard one bird in another plot where the species w^as not 

 encountered the previous or subsequent springs — deep within the 

 chaparral belt and surrounded by dense chaparral but on an eroding 

 slope in a canj^on where shrubs were shorter and sparser. This 

 record suggests that dispersal, at least of young, takes place some time 

 during fall or early ^nnte^. When the young take up their first 

 territory is unknown, but some occupancy of good feeding areas may 

 take place first, perhaps accounting for the approximately 15 rufous- 



