The MacGillivray’s Warbler (Oporornis tolmiei), is a small species of New World warbler. They are migratory and spend their summers in temperate forests located in the western United States, and in boreal forests of west Canada. In autumn, these birds will migrate back to Central America, where they will stay in temperate shrublands for the winter.
Like all members of the genus Oporornis, these birds are sluggish and heavy warblers with short tails, preferring to spend most of their time on, or near the ground, except when singing. They grow to be 5 to 6 inches in length. They are an olive-green color on their upperparts and dull yellow below. Males have black heads and breasts, while females and immature birds have drab light gray heads and white eye-rings. MacGillivray’s Warblers are almost identical to their eastern counterparts, the Mourning Warblers, the only true difference between the two species being the Mourning Warbler’s lack of an eye-ring.
The MacGillivray’s Warbler was named by John James Audubon in honor of Scottish ornithologist William MacGillivray, although the proper credit to its discovery goes to John Kirk Townsend. The scientific name “tolmiei” was given in honor of William Fraser Tolmie.