There are two adult plumage variations known as the tan-striped and white-striped forms. Both variations feature dark eyes, a white throat, yellow patch in front of the eyes, and gray bill. Both male and female white-striped birds are more aggressive than tan-striped birds during the breeding season.
Fun Fact Although they look nothing alike and aren't particularly closely related, the White-throated Sparrow and the Dark-eyed Junco occasionally mate and produce hybrids. The resulting offspring look like grayish, dully marked White-throated Sparrows with white outer tail feathers.