What feature primarily gives the male Mourning Warbler its distinctive name?
Answer
The slate-gray hood extending down the throat and chest
The name is derived directly from the adult male’s plumage pattern, specifically the neat, dark hood that appears as a complete slate-gray covering over the head, throat, and upper chest.

Related Questions
What feature primarily gives the male Mourning Warbler its distinctive name?How does the female Mourning Warbler's throat and breast typically appear compared to the male's namesake hood?Despite its somber moniker, how is the Mourning Warbler's song usually described?Which habitat component do Mourning Warblers strongly prefer in their breeding grounds?Where do Mourning Warblers primarily forage for insects?What color provides a striking contrast to the male's dark upper parts?Why is confirming the Mourning Warbler's identity by sight often challenging for observers?What region primarily constitutes the wintering grounds for the Mourning Warbler?How might the male's plumage appear when observed in deep shade?Which area is included in the described North American breeding range of the Mourning Warbler?