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This double-page spread of Swainson’s Hawks from The Crossley ID Guide: Raptors captures the variable plumage you might see among a large mid-migration group.
Swainson’s Hawks have one of the most spectacular migrations of any raptor, with some birds migrating from the northern Great Plains to the grasslands of Argentina. En route, they form large flocks, passing over the Great Plains in big groups and over hawk watches such as Corpus Christi and sites in the Lower Rio Grande Valley of Texas. The biggest flights pass through Veracruz, MX, and Panama, where birds are funneled into a narrow bottleneck before continuing south into South America.
Swainson’s Hawks have the most variable plumage of any buteo, with perhaps the exception of Red-tailed Hawk, but the good thing about Swainson’s is that all birds can be identified by the same suite of few characters: long tapered wings, with dark flight feathers, usually paler underwing coverts, and almost always pale undertail coverts. The upperparts, wing, and tail feathers of all variants are similar in appearance, so focus on the body and underwing coverts to get a sense of the variation of Swainson’s.
In the book, this is one of the mystery quiz pages where each bird is numbered and the solutions are given at the back of the book. One more thing to look forward to!