Figure 1:

Adult male mountain gorillas (n = 28) had lower mean baseline faecal glucocorticoid metabolite concentrations than adult females (n = 44; F = 13.20, P < 0.001, n = 1936 faecal samples). Individual points represent the mean ± 1.5 SD for each animal; the vertical black lines are the upper and lower 95% confidence intervals. The blue line represents the mean of the mean ± 1.5 SD for all adult males; the red line represents the mean of the mean ± 1.5 SD for all adult females.