Very local and endangered small sparrow of highlands in central Mexico; endemic. Occurs in bunchgrass within areas of open pine woods; often rather elusive. Feeds on the ground in grassy areas and adjacent plowed fields, but sings from prominent grass stalks. Plumage looks much like Song Sparrow, with gray face, black-streaked breast and flanks, and rusty wings. Song Sparrow is larger and bulkier, with less extensive rusty in wings, and almost always lives in wetter habitats.