A bright-eyed, hefty billed bird of forests and scrublands. Tends to hold its tail cocked up and wings drooped, especially when feeding. Typically appears almost entirely warm brown; dark above and paler below with some gray on head. Gray Trembler lacks the brown hues of Brown Trembler and has some degree of white below. White-breasted Thrasher has largely bright white underparts and a dark red eye (not yellow as in Brown Trembler). Song is a slow jumble of rich whistles and high-pitched sibilant notes. Calls include scattered whistles and harsh scolding notes.