These are nearly as common as the above, but probably not as well known, as they keep well up in the tops of the taller trees, where they also build their nests, very much the same as the [Red-eye]. Their song is much more pleasant. Four eggs, like above (.72 × .52).
CASSIN VIREO.
629a. Lanivireo solitarius cassini. 5 inches.
To be found west of the Rockies from British Columbia south to Lower California and Mexico. In southern California, it is found breeding much more commonly than the [Western Warbling Vireo], placing its nest high in the oaks and coniferous trees. It belongs to the same musical family, keeping up its song from morning until night. The nest is made of similar material to the previous, and the eggs are the same, except in size (.75 × .58).
BLACK-CAPPED VIREO.
630. Vireo atricapillus. 4½ inches.
A smaller variety, the male marked with a black cap. Breeds in Texas, north to Kansas. Winters in Mexico (not illustrated).
HUTTON VIREO.
632. Vireo huttoni. 4½ inches.