Bird field guides once listed the Myrtle warbler and Audubon…
Bird field guides once listed the Myrtle warbler and Audubon’s warbler as two distinct species based on morphological differences. Current guides list them as one species, the Yellow-rumped Warbler, with two slightly different populations. The reclassification of the two birds into a single species was based on a reevaluation of the birds using the Biological Species Concept (BSC). To classify the two species as a single species under the BSC, biologists must have found that the Myrtle warbler and Audubon’s warbler…