Серый виреон Vireo vicinior

One of North America's most nondescript birds: pale gray above, lighter whitish below, with a hint of pale spectacles and wingbars. Long-tailed for a vireo, but with a typically thick bill. Occurs on dry rocky slopes with patches of dense brush and trees, especially oaks and junipers. Usually seen singly or in pairs, often detected by voice. Most similar to drab Bell's Vireo but note habitat and size differences. Also compare with Plumbeous Vireo, which is shorter-tailed and more boldly marked.