Fig. 6. Behavioural response of a receiver to offensive behaviour without urine release (filled columns; O, N=174 bouts) and to offensive behaviour accompanied by urine release (`offensive urine release'; open columns; O+U, N=86 bouts). Responses are measured as changes in the relative frequency of certain agonistic levels (levels -2, -1, defensive behaviour; levels 0, A, neutral behaviour; levels 1-5, offensive behaviour; see Materials and methods) from the preceding to the current time interval. Asterisks denote significant differences between the responses to offensive urine release and responses to offensive behaviour (^**P<0.01; multivariate ANOVA). Values are means +1 S.E.M.