Figure 5
From: Quality prevails over identity in the sexually selected vocalisations of an ageing mammal
Relationship between male rank and the minimum frequency of the sixth formant of groans. Lower values of dominance rank indicate higher-ranking males. Males tend to produce groans with a lower minimum frequency of the sixth formant when higher-ranking (linear relationship, marginally significant, P = 0.05). Dots represent mean values per year for each male and lines show repeated measures of the same individual across years.