1580s, of persons, "wearing a ruff;" by 1610s in animal and bird names, "having a ruff" of feathers, etc., from ruff (n.1). The American ruffed grouse is so called by 1782.
Entries linking to ruffed
ruff n.1
kind of large band or frill, stiffly starched, 1520s, originally in reference to sleeves (of collars, from 1550s), probably a shortened form of ruffle (n.). They were especially common in the late sixteenth and seventeenth centuries. Extended to distinctive sets of feathers on the necks of birds from 1690s.