Figure 2 : Changes in homing efficiency over five generations.

From: Cumulative culture can emerge from collective intelligence in animal groups

Figure 2

(a) Homing efficiency for all flights in the experimental group (red), the solo control group (black) and the fixed-pair control group (blue). The final (twelfth) flight of each generation in the experimental group and the equivalent (twelfth, twenty-fourth, thirty-sixth, forty-eighth and sixtieth) flights in the control groups are highlighted as bold symbols. Mann–Whitney–Wilcoxon test: **P<0.01 and P<0.05, for the solo versus experimental comparison and for the fixed-pair versus experimental comparison, respectively. Error bars show s.e.m. Inset shows linear mixed-effects model fitted to the final flights of each generation for all three treatment groups. (b) Examples of route development in the three treatment groups. The left panel shows final flights performed by each generation (first–fifth) in one chain in the experimental group; middle and right panels show the equivalent flights performed by a solo control bird and a fixed-pair control, respectively. The release point is indicated by a white dot, the home loft by a black dot. Scale bar represents 1 km. Map image: OS data © Crown copyright and database right (2017).