These 4-widespread species are often confused with on another. This direct comparison will make the differences easier to see. The song sparrow regulary shows a central chest spot, but the 3 other species may also have a central spot, so do not make identification soley on this mark. The savannah and vesper sparrow are typically seen in open, grassy habitats. The song and Lincoln´s prefer more cover.
Song Sparrow
Relatively heavier streaks than other species and heavy malar (p.xx) mark. Strong line behind the eye, smooth eyeline and cheek. This song sparrow shows a more distinct eye ring than the benchmark song sparrow shows.
Lincoln Sparrow
Clear gray above and below eye. Dark eyeline. Finer streaks than on song sparrow and buffy wash across upper chest.
Savannah Sparrow
Streak-headed appearance, yellow lores. Streaks finer than on song sparrow. Some races( p.xx) are much darker with heavier streaks.
Vesper Sparrow
Similar to savannah but more prominent eye ring. Compare length of wing tips vs that shown on benchmark song sparrow photograph. White outer tail feathers show in flight.