436 Birds of Colorado 
and the inner secondaries; middle and greater coverts tipped with 
white, forming a double wing-bar; below white, slightly washed on 
the sides and flanks with pale slaty-grey and a tinge of olive; iris 
brown, bill blackish, paler at the base of the lower mandible, legs 
dusky. Length 5-30; wing 3-15; tail 2-25; culmen -45; tarsus -75. 
The sexes are alike ; young birds are very similar to the adults, but 
have the back more brownish. 
Distribution.— Breeding in the Rocky Mountains region from southern 
Wyoming through Mexico to the State of Vera Cruz; further south 
in winter to Oaxaca. 
The Plumbeous Vireo is a fairly common summer bird in Colorado, 
passing along the eastern bases of the mountains during migration, 
and breeding chiefly in the mountains up to about 10,000 feet. It 
arrives from the south early in May—El Paso co. May 8rd, Allen & 
Brewster—passes up into the mountains about the end of the month, 
and breeds in June. The highest breeding locality seems to be 
Breckenridge, 9,700 feet (Carter apud Cooke). Other localities are: 
Loveland (Cooke), Estes Park (Kellogg), Boulder co. (Minot), Idaho 
Springs (Trippe), South Park (Allen), Pueblo (Beckham), and Wet 
Mountains (Lowe). It does not seem to be recorded from the western 
slopes or from the eastern plains hitherto. 
Habits.—This Vireo does not seem to be very different 
in its habits from the others, except that it appears to 
have a more decided liking for pine woods, in the recesses 
of which it is often to be found. The nest was first 
taken by Aiken in May, 1872, on Turkey Creek in El 
Paso co., and is described by Henshaw as composed 
of soft cottony substances bound with strips of bark 
and other fibrous material, and lined with fine grasses ; 
the eggs, four or five in number, are white, spotted 
chiefly at the larger end with reddish-brown. Fresh 
clutches may be looked for from June 10th to June 25th 
according to Gale’s notes. Minot does not consider 
its song so sweet as that of its eastern ally, the 
Solitary Vireo. 
Genus VIREO. 
Small Vireos with the tenth (outer) primary well developed, always 
more than one-third, often half, the length of the ninth, the latter 
shorter than the fourth. 
