Animal food, consisting primarily of insects and spiders, is actively
sought along branches and under leaves. Often a foraging bird will
leap to the underside of a branch and hover, mothlike, beneath a
cluster of leaves while extracting some insect. Some individuals hung
upside down on small branches, paridlike, while foraging. Lawrence
(1953:710), and Southern (1958:201) have recorded similar behavior of
the Red-eyed Vireo. Occasionally, I have seen a Bell Vireo fly from a
perch and capture an insect in the manner of a flycatcher. The birds
do not appear to be adept at this type of food-getting. Nolan
(1960:242) mentions Bell Vireos holding hard-bodied insects by means
of their feet while breaking the exoskeleton with the beak to obtain
the soft parts. Southern (1958:201) recorded a female Red-eyed Vireo
foraging on the ground; I have seen a Bell Vireo on the ground but
once, and it was gathering nesting material.

_Bathing_

On May 14, 1960, in a rill that empties into the northeastern edge of
the reservoir a female flew down from a perch six inches above the
surface, barely dipped into the water, flew to a perch 12 inches above
the water, violently shook her ruffled body feathers, quivered her
wings, and rapidly flicked her fanned tail. The entire procedure was
repeated three times in five minutes. She was accompanied by a singing
male that did not bathe.

Nolan (1960:241) reports a male Bell Vireo bathing by rubbing against
leaves wet with dew; he notes that the White-eyed Vireo bathes in a
similar manner. Southern (1958:201) twice observed Red-eyed Vireos
bathing in water that dropped from wet leaves. In my study area in
1960, only territories 7, 8, 9, and 10 were not immediately adjacent
to permanent water. The pairs of Bell Vireos in those territories
presumably had to reply on wet vegetation for bathing.

VOCALIZATIONS

The male Bell Vireo begins to sing regularly soon after its arrival in
spring. Some daily singing continues following the cessation of
breeding activities until departure of the species in late summer or
early fall. The highest sustained rate of song occurs on the first and
second days of nest building. Because careful records of
meteorological data were not kept, I cannot significantly correlate
rates of song and specific temperatures and other weather conditions.
Frequency of song was reduced when the temperature rose above 90 deg. F.,
as it did on many days in June, 1960. N