The Arizona Crested Flycatcher 
occupied by these paired doubles; and the group may be separated by an 
interval of a hundred yards or so from the next quartet. The arrange¬ 
ment is evidently studied, and it must be mutually agreeable, for the two 
species are upon the best of terms, and I have never seen evidence of 
jealousy or ill-will on the part of either, though I have camped right under 
their nests. 
Verticalis is evidently the follower, the “copycat,” for the Cassins 
invariably begin nesting first. Most nests are under way by the third 
week of April (there is one record by Fred Truesdale of a set of five taken 
at Shandon on the 28th day of March, 1914); while sets of verticalis are 
seldom complete before the 15th of May. Apart from this, there is no 
constant difference either in the size, composition, or placing of the nest; 
shape, color, or size of eggs; or in the attitude of the birds toward friends 
or enemies. Cassin will chase a Raven as far as neighbor Western, and 
Mrs. Western will applaud the act as heartily (and as unresentedly) as will 
Mrs. Cassin. That the two strains remain inviolably distinct under 
such circumstances is either a tribute to the virtue of the birds, or a 
monument to our own lack of perspicacity in discerning differences or 
incompatibilities greater than we now suppose to exist. 
No. 167 
Arizona Crested Flycatcher 
A. O. U. No. 453. Myiarchus magister magister Ridgway. 
Description. —Adults (sexes alike): Pileum dresden brown, the feathers darker 
centrally, the remaining upperparts chiefly olivaceous gray (nearly Saccardo’s olive), 
on back graying, on hind neck and sides of neck, the upper tail-coverts and exposed 
edges of rectrices pale brownish; tertials and rectrices in superior aspect brownish dusky, 
the exposed edges of primaries and inner webs of rectrices cinnamon; the wing-coverts 
broadly tipped and the tertials broadly edged on outer webs with brownish white; chin, 
throat, sides of neck, and breast, broadly ashy gray; remaining underparts, including 
axillars and wing-linings, pale yellow (barium yellow). Bill and feet black. Av. 
length of adult males (skins): 217 (8.55); wing 109 (4.30); tail 100 (3.94); bill 24 (.945); 
tarsus 24.7 (.97). Females somewhat smaller. 
Recognition Marks. —Towhee size; requires careful discrimination from the 
Ash-throated Flycatcher, M. c. cinerascens. It is much larger, and the yellow of abdo¬ 
men, etc., is both darker in tone and much more extensive. 
Nesting. —Not known to breed in California, but probably does so. Nest: 
Placed in old woodpecker hole in sahuaro (giant) cactus or, more rarely, in mesquite 
tree; a heavy cushion of hair or fur, guarded, almost invariably, by a cast-off snake- 
skin. Eggs: 3 to 5; much like those of M. cinerascens, but slightly darker and more 
heavily marked; almost indistinguishable, save for size, from those of Myiarchus 
crinitus. Av. size 25.4 x 18 (1.00 x .70). Season: June. 
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