Bell's vireo (Vireo bellii) is a songbird that migrates between a breeding range in Western North America and a winter range in Central America. It is dull olive-gray above and whitish below. It has a faint white eye ring and faint wing bars.
This bird was named by Audubon for John Graham Bell, who accompanied him on his trip up the Missouri River in the 1840s.
The least Bell's vireo (Vireo bellii pusillus) is an endangered subspecies in Southern California. Consideration of Bell's vireo has been a factor in several land development projects, to protect least Bell's vireo habitat. The decline of the least Bell's vireo is mostly due to a loss of riparian habitat.