Figure 3.

(a) Within-group relatedness of different group sizes by juvenile presence (right) or absence (left) shows that groups with juveniles have higher relatedness than adult-only groups (combined Wilcoxon signed-rank tests for groups of two to five lizards, Z = −4.41, p < 0.001). Horizontal grey reference lines correspond to a relatedness value of 0, expected if groups are composed of unrelated individuals. Histograms show the number of groups of each size, and error bars represent ±1 s.d. (b) Per cent of social juveniles (n = 117) in aggregations of differing kin relationship classes. White wedges denote different categories of nuclear family relationships (57% total). White, nuclear family; grey, extended family; black, unrelated.