312 U. 8. NATIONAL MUSEUM BULLETIN 211 



feet and 37 in 1947 averaged 22.4 feet above the ground. (Many of 

 the nesting trees, being in gardens or along the streets, had their 

 lower branches trimmed.) Nests were ordinarily placed near the 

 ends of branches in thick tufts of needles, and often partly supported 

 by bunches of cones. The birds occasionally used planted Monterey 

 cypress also. 



The nest was described by Dawson (1923) as "a sturdy, tidy struc- 

 ture of interlaced twigs and grasses, strengthened by a matrix of mud 

 or dried cowdung, and carefully lined with coiled rootlets or horse- 

 hair." Some writers report mud used in the nest and others make no 

 mention of it. A "mud cup" is mentioned by I. McT. Cowan (MS.) 

 at Vancouver, British Columbia. Schorger (1934), in his description 

 of a nest in Wisconsin, does not mention mud. Goss (1891) says 

 that the nests he found on the ground at Chama, N. Mex. "were all 

 without a trace of mud." 



At my colony grasses, pine needles, etc., were seen in the bills of 

 nest-building females; many females frequently gathered horse manure 

 and mud, a combination that, when dry, makes a firm, plasterlike 

 cup. 



The dimensions are given by Macoun (Macoun and Macoun, 1909) : 

 "In size it averages over 6 inches across, with a cup over 3 inches and 

 a depth of at least \}{ inches." 



In Phase 2 (nest-building, copulation, and egg-laying) the male, 

 although he takes no part in the actual construction of the nest, 

 usually accompanies the female on each trip as she gathers material 

 and carries it to the nest. At this time they make a long, continuous 

 series of trips in contrast to the toying with and dropping of nest 

 materials, or occasional trips to a nest-site, of Phase 1. When the 

 female enters the tuft to place the material and mold the nest, the 

 male perches nearby and displays the ruff-out, uttering schl-r-r-r-up 

 and squeee. He uses one of several habitual guard perches, a wire, a 

 pole or a branch tip. From this perch he may drive other males if 

 they come near the nest site or into the tree. In this respect there is a 

 certain amount of localized aggression by the male. But such local- 

 ization does not take place until after the pairs have been formed in 

 Phase 1. The greatest portion of the male's aggressive activity is 

 directly concerned with guarding his female against the approaches 

 of other males. This guarding, or aggression concerned with a sexual 

 situation which reaches its height in Phase 2, is not localized; i. e., 

 it has little, or only incidental, connection with any particular area or 

 territory and may occur at any point on the wires, along the streets, 

 on the edge of the creek, or several hundred yards out on the adjacent 

 marsh. 



In Phase 2 the female exhibits the pre-coitional display frequently, 



