Bell’s Vireo 437 
This genus, containing a considerable number of species, ranges over 
North America as far south as Costa Rica and throughout the Greater 
Antilles (for key, see p. 431). 
Bell’s Vireo. Vireo bellz. 
A.O.U. Checklist no 633—Colorado Records—Thorne 87, p. 264 
(error apud Cooke); Cooke 97, p. 218; H. G. Smith 03, p. 438; 05, 
p. 82 ; 08, p. 189. 
Description.—Male—Above dull greyish-brown, slightly tinged with 
olive, more so on the rump and upper tail-coverts ; orbital ring and 
supra-loral streak obscurely white ; wings and tail dull dusky with 
paler edgings, and an obscure double wing-band formed by the pale 
tips of the middle and greater coverts ; below white, tinged on the sides, 
flanks, under tail-coverts, axillaries and under wing-coverts with sulphur- 
yellow; iris brown, bill pale horn, lower mandible paler, legs dusky 
horn. Length 4-15; wing 2-20; tail 1-80; culmen -38; tarsus -75. 
The sexes are alike; the young birds closely resemble the adults, 
but the wing-bands are more distinct and the inner secondaries are 
edged with yellowish-white. 
Distribution.—Breeding in the prairie regions from North Dakota 
and Indiana southwards to north-east Mexico ; in winter further south 
through Mexico to Oaxaca. Bell’s Vireo, long suspected to be a regular 
summer visitor to Colorado, has only recently, through the observations 
of H. G. Smith, been proved to be so. He has taken it in con- 
siderable numbers at Julesburg, Wray and Holly, all localities on the 
eastern border of the State, between the 18th of May and 31st of August, 
while his first example was obtained on Clear Creek near Denver on 
June 6th, 1903. It may be considered a regular summer bird in the 
eastern half of the State. 
Habits.—Goss writes: “These active birds inhabit 
dense patches of bushes and briers on the prairies ; hedge- 
fences are also a favourite resort. Their call and alarm 
notes are rather harsh, and their song does not rank 
very high. Their deep, cup-shaped nests are suspended 
from slender forks of twigs or vines and are composed 
of lint-like strippings from plants, neatly interwoven 
with bits of old leaves, and lined with fine weed stems, 
and in some cases hairs. The eggs, usually four in number, 
are pure white, thinly speckled at the larger end with 
dark reddish-brown, and measure ‘69 x ‘50.” 
