Separation of Palm from Myrtle is straightforward, Palms always show bright yellow undertail coverts, a character not shared with the other species. A dull Magnolia Warbler in fall may approximate a fall-plumaged Myrtle, but it should exhibit a yellowish wash to the underparts, a character absent in the latter species. In addition, the undertail pattern of the Magnolia shows a white band across the base of the tail, while the Myrtle shows a large white patch extending through the center of tail from it s base to tip. Lastly, Magnolias tend to have a grayish head and back, with a uniform face pattern, while the Myrtle tends to have brown upper-parts and a noticeable supercillium. Cape Mays are among the most variable of all fall warblers and in some instances may look like a Myrtle.
Structure can often be a good method to separate the two species.
Cape Mays have a more slender bill and shorter tail. The yellow in the rump is much duller than on a Myrtle and often shows a greenish tone. The back is also more uniform and the underparts are less streaked. Cape Mays often show a yellow wash on the underparts, a character not shared with the Myrtle. In juvenile plumage the Myrtle lacks its yellow rump.