Figure 11.

The proportional decrease in chamber area with depth of Pogonomyrmex badius nests is similar no matter what the colony size. Every 10-fold increase in depth is associated with a 75% decrease in summed chamber area in the decile (note log-log scale). Depths are the mean depths for each decile and size class. None of the slopes are significantly different from each other: slope of the log-log regression was − 0.59. Intercepts were: size class 0 = 1.69; size class 1 = 2.40; size class 2 = 2.72; size class 3 = 3.09; size class 4 = 3.35. These estimate the area at 1 cm depth, and have only mathematical reality. Actual mean areas in the uppermost deciles were 38, 190, 516, 1700 and 2670 cm² for size classes 0 to 4, respectively.