Warbler Guy, which warblers are superspecies?

That’s a fine question, Jeremy (in Boise, ID).

Given a superspecies consists of two or more species that evolved recently into isolated breeding ranges next to each other, it is not surprising that superspecies’ members are closely related.

Among songbirds, think of Eastern and Western Meadowlarks. Their breeding ranges are separated across North America and are nearly isolated except for a small overlap area. The same kind of breeding isolation geography pattern occurs in more than 100 North American species that are considered members of 53 total superspecies.

Of these 53, some wood-warbler species qualify. Note the distinct breeding ranges of the Black-throated Green superspecies consisting of this species along with Black-throated Gray, Hermit, Townsend’s, and Golden-cheeked Warbler.

Other warbler superspecies include 1) Nashville, Virginia’s, and Colima; 2) Northern and Tropical Parula; 3) Yellow-throated and Grace’s; and 4) Mourning and MacGillivray’s.