The very similar Bell’s Sparrow breeds in coastal California and the Mojave desert, but overlaps on its wintering grounds with Sagebrush Sparrow. Bell’s Sparrows from coastal California are somewhat darker, with darker stripes bordering the throat, than Sagebrush Sparrows—but Bell’s Sparrows from the Mojave are paler and more like Sagebrush Sparrows. Overall, the two species are extremely difficult to tell apart, and many times the best a birder can do on the wintering grounds is mark these birds as Bell’s/Sagebrush. Black-throated Sparrow breeds in more desert habitats of the Southwest than Sagebrush Sparrow does. The Black-throated Sparrow has a bold black bib, crown, and cheek, and a white stripes over the eye and white malar or “mustache” stripe. Vesper Sparrows are browner than Sagebrush Sparrows, with streaking on the breast and without the contrasting gray head. They also show more white in the outer tail in flight.
The Sagebrush Sparrow was formerly considered one of five subspecies of the “Sage Sparrow." In 2013, Sage Sparrow was divided into two different species: one subspecies became the Sagebrush Sparrow, and the other four were classified as subspecies of Bell’s Sparrow. Bell's Sparrow has more subspecies and greater geographic variation because of their adaptability to a greater variety of habitat types and mountain ranges in and around California. The Sagebrush Sparrow, with somewhat paler plumage and longer wings (attributed to longer migrations), is fairly uniform across its broader range in the intermountain West of North America.
Find This Bird
As with many inconspicuous sparrows, the best way to find Sagebrush Sparrows is to look for them in the early morning during the breeding season, when males perch out in the open on tall shrubs and sing for your attention. At other times they may be considerably harder to find. Just be aware that in the right habitat—undisturbed sagebrush—these sparrows are fairly numerous, and they tend to forage on the ground and scurry rather than fly between patches of shrub cover. Patient watching and listening either for the sounds of foraging or for this bird’s bell-like tink call will help you find them.