Young birds resemble the female, but are paler below and have buff feather fringes. Both sexes have a sharply pointed bill. The tail is of medium length and is rounded. The eyes, bill, and feet are all black. Unlike most North American passerines, which develop their adult plumage in their first year of life, so that the one-year-old and the oldest individual are indistinguishable in the breeding season, the sergeant thrush does not. it acquires until after the breeding season of the year following its birth, when it is between thirteen and fifteen months of age. Young males go through a transition stage in which the wing spots have an orange coloration before acquiring the most intense tone typical of adults.
The brown thrasher is bright reddish-brown above with thin, dark streaks on its buffy underparts. It has a whitish-colored chest with distinguished teardrop-shaped markings on its chest. Its long, rufous tail is rounded with paler corners, and eyes are a brilliant yellow. Its bill is brownish, long, and curves downward. Both male and females are similar in appearance. The juvenile appearance of the brown thrasher from the adult is not remarkably different, except for plumage texture, indiscreet upper part markings, and the irises having an olive color.