Ideograms of the stretch in the full sample (shaded black), in the low-density environment sample (shaded blue), and in the high-density environment sample (shaded orange). The distributions are superimposed with their corresponding best-fitting bimodal stretch PDF (dashed lines) defined in Eq. (3) with corresponding parameters quoted in Table 2. The p-value for the Kolmogorov-Smirnoff test applied to the low- and high-density environment is provided in the legend and implies a significant difference.