Figures & data
Figure 1. Percentage of ant-wasp encounters resulting in aggressive acts by wasps (A) or ants (B), as a function of the ratio between average ant and wasp abundance at protein baits (n = number of bait stations per ratio category). Box plots show 10th and 90th percentiles (whiskers), 25th and 75th percentiles (boundary of the box), median (line) and outliers (black dots). All data were obtained by videotaping ant-wasp interactions at each bait station for approximately 40 min (see ref. Citation4 for details). Inset pictures show the typical postures of (A) wasps just before picking up an ant and dropping it away from the resource, or (B) ants adopting a threatening posture with wide open mandibles and a drop of acid at the tip of the gaster (white arrow). Below the x-axis of (B) is a schematic representation of ants and wasps (small and large black dots, respectively) when both species were present around the food bait (large gray dot). The proportion of aggressive interactions is relative to the number of passive contacts (contacts that resulted in no response from either species). This proportion differed significantly in both wasps and ants according to the category of ant/wasp abundance ratio (Kruskal-Wallis tests: H = 9.42, p = 0.024 and H = 8.43, p = 0.038; respectively). Different letters indicate a significant difference after a Dunn’s post-hoc test (p < 0.05).
