From April to August, 1993 to 1995, we studied the aposematic behaviour patterns of striped skunks, Mephitis mephitis, incidentally while ground-tracking radio-marked animals. During 2668 h of tracking, 207 defensive postures were displayed by 34 radio-collared (27 females, 7 males) and 21 unidentified skunks. Skunks most often advertised their noxiousness using Tail-up (69.1% occurrence) and Stomp (17.4%). Encounters were frequently (42.5%) terminated by the skunk running away from the source of disturbance. Most warning behaviour was directed at radio-trackers (95.7%), and the remainder was displayed to a variety of predatory and non-predatory animals or objects. Stomp occurred more frequently in taller vegetation, where visual advertisement was limited. Reaction distance of skunks disturbed by observers (median = 6 m) was not affected by wind, movement or vegetation height. The small awareness circle and high tolerance of skunks to disturbance are consistent with the life history traits of aposematic animals.