What subtle field marks do many birds in the *Parulidae* family rely on for identification besides brilliant coloration?

Answer

Wing bars, faint streaks, or spectacles (eye rings)

A significant portion of the *Parulidae* family distinguishes itself using subtle field marks such as wing bars, faint streaks, or eye rings, rather than relying solely on bright coloration.

What subtle field marks do many birds in the *Parulidae* family rely on for identification besides brilliant coloration?
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