560 "U.S. NATIONAL MUSEUM BULLETIN 237 part x 



or it may be abundant (Yosemite Valley; Grinnell and Storer, 1924). 



In early October, in Yosemite Valley, the species has been found 

 "frequenting the same thickets as the Golden-crowned Sparrows 

 [Zonotrichia atricapilla] which had then just arrived from the north," 

 (Grinnell and Storer, 1924), while K. Hoffmann (1927) states that "in 

 migration it associates with Gambel Sparrows [Zonotrichia leucophrys 

 gambelii] in the bushes in the deserts of southeastern California * * *." 

 In fall it has also been noted in StiUwater County, Mont., in association 

 with rufous-sided towhees (C. M. Welch, 1936). There is but little 

 tendency, however, toward actual gregariousness. Statements by 

 GrinneU and Storer (1924) and L. Huey (1942) indicate that the green- 

 tail is basically nonsocial after the breeding season. 



Winter. — Some of the wintering populations may be fairly dense. 

 In giving the species' status in the Organ Pipe Cactus National 

 Monument area of Arizona, Huey (1942) states that it is "perhaps the 

 most generally distributed winter visitor. While never in concentrated 

 numbers, it was found singly in almost every place where vegetation 

 was dense enough to given it shelter." From middle or late September 

 until mid-May it is common to abundant in parts of Sonora and 

 Sinaloa (A. H. Miller in MiUer, Friedmann, Giiscom, and Moore, 

 1957), to mention but two sections of Mexico in which it sojourns in 

 the nonbreeding season. 



Among the rare individuals that have been found wmtering in the 

 eastern United States, two showed an attraction to white-throated 

 sparrows {Zonotrichia albicoUis). First, G. C. Embody (1908) writes of 

 a vagrant greentail collected in Virginia that was "in company with 

 White-throated Sparrows, in a thicket along the edge of an open 

 field * * *." Second, S. A. Ehot (1948) tells of a bird, evidently a 

 first-year male, which appeared as an accidental visitor at a North- 

 hampton, Mass., feeding station: "From January 22 on, its favorite 

 companion was a White-throated Sparrow * * *^ and as it matured its 

 behavior towards this female White-throat became more and more 

 devoted. In April it came but little to the feed but could be found 

 nearby, always with the White-throat. On April 15, Mrs. Risley had 

 her last look at it, closely following the White-throat and apparently 

 courting it. We supposed that the White-throat went north that 

 evening with the Green-tail in pursuit, but on April 26 a group from 

 Pittsfield found it moping by itself in the forsythia! What happened 

 next, nobody knows." 



The apparent special "affinity" between the green-tailed towhee 

 and the Zonotrichia sparrows certainly merits further study. As this 

 towhee does appear to be a true Pipilo, one is tempted to speculate 

 whether the genera Pipilo and Zonotrichia are more closely related 

 than the 1957 A.O.U. Check-List indicates. 



