inches in height (Table 5). The height above ground of the
nests does not vary appreciably as the season progresses as is the
case with nests of Red-eyed Vireos, for which Lawrence (1953:54) noted
that late nests were placed higher than those built earlier in the
season.

Most nests are so situated that they are protected and concealed by
the dense foliage of trees. Where nests are placed in low bushes, as
coralberry or dogwood, the bush is invariably overhung by the foliage
of a much taller shrub or tree.

The nest tree or shrub was in every instance situated at the edge of a
thicket or isolated from adjacent trees by several feet. Preference
for open situations is characteristic of the species. In contrast, the
nest of the White-eyed Vireo (Bent, 1950:229) is placed toward the
center of thickets.

In the choice of sites in the study area, the Bell Vireos were almost
unopposed by other avian species, owing to the size of the fork
utilized and the fact that the nests are located peripherally, rather
than centrally, in the bush or tree. This lack of competition for a
nest-site provides a Bell Vireo with an ample supply of nest-sites
within any one territory.

TABLE 5. NEST-SITES UTILIZED IN 1960.

====================================================================
| Number | Average | Average
Plant | of | height of | height of
| nests | plant | nest
-----------------------------+--------+---------------+-------------
_Ulmus americana_ | 4 | 7 ft. 6 in. | 2 ft. 3 in.
_Maclura pomifera_ | 20 | 13 ft. 11 in. | 1 ft. 11 in.
_Crataegus mollis_ | 1 | 11 ft. | 3 ft. 1 in.
_Gleditsia triacanthos_ | 2 | 15 ft. 6 in. | 1 ft. 9 in.
_Acer negundo_ | 4 | 8 ft. 9 in. | 2 ft. 5 in.
_Cornus drummondi_ | 2 | 8 ft. | 2 ft. 8 in.
_Symphoricarpos orbiculatus_ | 3 | 3 ft. | 1 ft. 10 in.
| | |
7 | 36 | 11 ft. 4 in. | 2 ft. 3 in.
-----------------------------+--------+---------------+-------------

Selection of the first nest-site may take as long as two days,
possibly owing to incomplete development of the nesting tendency, but
more likely to a general lack of familiarity with the terri