The female has, on average, a narrower black back band, slightly duller upperparts and buffer underparts than the male. Her cap may be gray, but many females have black caps and cannot be reliably distinguished from the male in the field. In the northeastern United States, at least 10% of females have black caps, but the proportion rises to 40–80% in the Rocky Mountains, Mexico and the southeastern U.S. Juveniles are similar to the adult, but duller plumaged.
The Brown-headed Nuthatch is a small songbird found in pine forests throughout the Southeastern United States. Genetic analyses indicated low differentiation between northern and southern populations in Florida. A population on the Bahamas showed moderate to high differentiation compared with Florida populations. The bird, like other nuthatches, possesses a sharp black nail-like beak, which it uses to pound open seeds. It is a frequent visitor to feeding stations and is highly fond of sunflower seeds and suet cakes.