270 BULLETIN 19 7, UNITED STATES NATIONAL MUSEUM 



Nesting. — Grinnell and Swarth (1913) found a nest in the upper 

 tangle of a greasewood {Adenostoma fasciculatwn). This nest was 

 33 inches from the ground, which was sloping, and was discernible 

 for several yards though well surrounded by the sparsely leaved 

 greasewood twigs. Another nest, also found on the same date, May 

 21, in the same kind of a bush, was 36 inches above the ground. The 

 nests are "similar to other vireo's nests in shape and semi-pensile 

 attachment. The main support is at the rims, but their situation 

 among i\\Q. close-set, obliquely upright, stiffish stems of the grease- 

 wood afforded some support by minor twigs." They give details 

 as follows : 



The measurements of the nests are, respectively, of each of the two nests in 

 each respect : outside diameter, about 76, 73 mm. ; inside diameter, 48, 47 ; 

 outside depth, 54, 59; inside depth, 41, 43. The nests are composed largely of 

 silvery gray weathered grass and plant fibers, usually with the vascular bundles 

 unraveled. Some of these elements were evidently grass blades, some stems of 

 plants, and others the shredded bark of weed-stalks. There is an admixture 

 of tenacious spider-web, and portions of .spider cocoons ; on the very outside, in 

 both cases, are many unbroken, tridentate, gray leaves of the sagebrush. In- 

 ternally the nests are lined with a distinct layer of slender, disintegrated, hair- 

 like fibers of great length, so that the inner surfaces of the nests are firm and 

 smooth, but porous. 



Florence M. Bailey (1928) describes New Mexico nests as being 

 "in thorny bushes or trees, 4 to 6 feet from the ground, occasionally 

 supported underneath or on sides ; made sometimes of mesquite bark 

 and loosely woven coarse grass, lined with fine grass, but also made 

 of plant fibers, spider web, and cocoons, lined with long vegetable 

 fibers and decorated with sagebrush leaves." She describes, how- 

 ever (1904), a nest found in junipers at Montoya, northeastern New 

 Mexico, which was composed "principally of shreds of bark, ap- 

 parently the soft juniper bark, and, unlike ordinary vireo nests, was 

 unadorned." 



W. E. D. Scott (1885) found a number of nests in Arizona of 

 which one was "about seven feet from the ground, in smooth, flat 

 country, at an altitude of about 3500 feet." Another nest was built 

 near the center of a mesquite and was about 6 feet from the ground in 

 an upright V formed by two upright limbs. Although admitting that 

 the rim of the nest was attached for almost half an inch of its circum- 

 ference to a small twig on one side, and for an inch to another twig 

 on the other side, he states : "The bottom of the nest outside does not 

 quite rest in the angle of the V, but the sides rest firmly against the 

 limbs forming it, and the result is a Vireo's nest resting in a crotch, 

 and in no degree pensile." 



Yet another nest he describes as — 



built in a kind of thorn bush, almost at the extremity of one of the upper and 

 overhanging branches, six feet from the ground. It is composed externally of the 



