230 BULLETIN 195, UNITED STATES NATIONAL MUSEUM 



tiire bird, a song so soft that it could have been heard only within a 

 distance of a few feet. 



Noisy and unmusical though the California representative of the 

 species may be, its cries are never shrill or mournful but convey a sug- 

 gestion of rollicking good humor, rather pleasing than otherwise. 



Field marks, — The cactus wren is easily distinguished from any 

 other North American wren by its much greater size, as well as by the 

 fact that it never carries' its tail in the tilted position so familiar in 

 the smaller species. The only bird with which it might be confused, 

 by reason of size, general appearance, and arid habitat, is the sage 

 thrasher, from which it differs, among other respects, in its longer 

 bill and white-streaked back. When flushed, its most conspicuous 

 feature is the white-banded tail, which is widely extended in flight. 



Enemies. — In thickly populated districts the chief hazard to the 

 cactus wren undoubtedly lies in the fact that its conspicuous, conveni- 

 ently located nests offer an irresistible challenge to vandals. This is 

 but one of the many instances in which defenses that cope successfully 

 with natural enemies prove but traps and delusions when the human 

 element enters. Fortunately, the greater part of the cactus wren's 

 domain presents' little allurement to colonists, so the species may well 

 prosper for many years to come. 



In other respects, the cactus wren's nesting habits must be of gi'eat 

 advantage. In cholla cacti the viciously sharp, barbed spines, to which 

 the birds themselves seem utterly oblivious, must very effectually bar 

 the way to climbing predators, while the covering of the nest shields 

 it contents from flying enemies, as well as providing shelter from the 

 elements. In leafy bushes or trees, the nests are placed at the ends of 

 the branches in the outer foliage, thus again making them almost 

 inaccessible to climbers. These precautions, of course, will not avail 

 against the California jay, and the complete disappearance of two sets 

 of eggs in my own yard, without damage to the nests, could be ascribed 

 only to that culprit. 



Winter. — Though not truly migratory, cactus wrens may shift about 

 somewhat when not engaged in nesting duties. In writing of this 

 species in southern Arizona and southwestern New Mexico, H. W. 

 Henshaw (1875) reported that "in the fall, the thickets bordering 

 the streams are frequently resorted to by them." Perhaps such moves 

 into denser cover have contributed to the general impression that the 

 wrens are less common in winter. They also seem less vociferous at 

 this time of year and hence more likely to be overlooked. Near Los 

 Angeles, the birds are often absent from their breeding grounds in 

 winter for days or weeks at a time, but they reappear often enough 

 to show that they have performed no actual migration. 



The paired birds seem to remain together through winter, and, aside 

 from pursuits, no courtship demonstrations have been noted. 



