Vireo gilvus
The warbling vireo may be one of the most widespread of the vireos, but its habit of foraging in dense vegetation and high in the trees makes it fairly elusive. It is more often heard rather than seen. Birders who are persistent and patient can often find it moving through the tree tops.
It moves about constantly, catching insects and caterpillars, eating eggs of moths and butterflies. Occasionally, I have seen vireos eating small fruits from my mulberry and red osier dogwood.
When observing a vireo, notice the shape of its beak, which is slightly down-curved at the end and a bit heavier than that of the warbler, whose bill is pointed.
The warbling vireo has a buffy stripe over the eye. It is a gray to gray olive on its upper parts and has a whitish gray breast. The vireo measures 5 inches with a wingspan of 8 inches.
The name is most revealing, since the male has a warbling song. The mnemonic often used is, "I'll seize you and I'll squeeze you and I'll squeeze you 'til you squirt!" Males often sing from the nest that they help build. Vireos are neotropical migrants who appear in the spring with the emergence of insects, leaving in the fall, as insect activity wanes.
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* BILL FENIMORE is owner of the Layton Wild Bird Center, www.wildbird.com/layton. Join the Wild Bird Center on one of its free bird walks. Call 801-525-8400 for more information.
