602 
BIRDS OF NEW MEXICO 
washed with grayish olive-yellow. Young: Upperparts pinkish gray and pinkish 
drab; underparts pure white, sides and flanks tinged with pale yellowish. 
Range. —Breeds along the Lower Colorado in California, in Arizona, to central- 
western Texas and south to Chihuahua, Sonora, and Sinaloa. 
State Records. —The Arizona Least Vireo has been taken at Fort Bowie, 
Arizona, just to the west of the New Mexico line, while in Texas it has been collected 
at El Paso, and in New Mexico it was taken on the Gila River, May 29, 
1876 (Stephens).—W. W. Cooke. 
Subgenus Lknivireo 
CASSIN VIREO: Vireo solit&rius c&ssini Xantus 
Description.— Length: 5-5.6 inches, wing 2.8-3, tail 2.1-2.3, bill from nostril .3, 
tarsus .7-.8. Adult male: Top and sides of head dark gray in sharp contrast to white of 
loral streak , orbital ring, and throat; back and scapulars dull olive-green, brighter on 
rump; tail and wings slaty, with light olive-green edgings, more yellowish on tail 
feathers, of which the outside ones have the outer web 
w’hite; wings with two distinct bands; underparts white, 
shaded with olive and yellow on sides; under mandible 
bluish gray, with black tip. Adult female: Similar but 
duller, head and neck browner gray,w*hite of underparts 
less pure. Young in juvenal plumage: Wings and tail 
as in adults, rest of upperparts brownish gray, under 
parts dull w r hite, flanks tinged with yellowish. 
Comparisons. —See Plumbeous Vireo, p. 603. 
Range. —Breeds in Transition Zone from southern British Columbia, south¬ 
western Alberta, and northwestern Montana south through California to San Pedro 
Martir Mountains, Lower California; eastward in migration through Arizona and 
New Mexico (casual in Colorado); winters in Mexico south to Oaxaca and Chiapas. 
State Records. —Breeding to the northwest and southw r est of New Mexico, the 
Cassin Vireo comes southeast in fall migration and passes through the State on its 
way to its Mexican winter home. It arrived on September 2, 1883, at Willis, 7,800 
feet (Henshaw r ), and was numerous. It enters the State, however, somewhat earlier, 
for one was taken, August 7,1908, at 6,600 feet in the Animas Mountains (Goldman). 
The most eastern record is that of the specimen taken on August 27,1903, at the base 
of Emery Peak near Folsom, a second one being taken September 11, 1903, close to 
the Colorado line near Bear Canyon (Ilow'ell). It is a tolerably common fall migrant 
at Apache (Anthony); and the last w T as taken near there on September 25, 1893, on 
the west side of the San Luis Mountains (Mearns). [In the spring of 1919, one w r as 
seen 35 miles southwest of Chloride at 7,000 feet, April 24, and one at Chloride, 
April 26 (Ligon).J 
Nest. —Usually 8 to 20 feet from the ground, hung in oaks, cottonwoods, maples, 
alders, dogwoods, manzanitas, buck brush, and also in conifers; compactly woven 
with shreds of inner bark, grasses, and bits of plant down, lined with fine grass stems, 
and decorated with pieces of white cocoon, and sometimes paper and string, bound 
with web. Eggs: 4 or 5, white, sparsely marked with smallish spots of brown. 
Food. —Nearly 98 per cent animal matter, about half being bugs—squash-bugs, 
leaf-bugs, stink-bugs, shield-bugs, leaf hoppers, tree hoppers, jumping plant lice, and 
black olive scale. Caterpillars and a few' moths make up more than 23 per cent of 
From Handbook of W'estern Iiirds 
Fig. 106. Cassin Vireo 
