Figure 1.

Stimuli used in the experiment: (a) disruptive with all markings of high contrast (AH); (b) disruptive with all markings of low contrast (AL); (c) disruptive with high-contrast edge and low-contrast internal markings (EH); (d) disruptive with low-contrast edge and high-contrast inside markings (IH); (e) average of the markings on treatment AL (L); (f) average of the markings on treatments EH/IH (M); and (g) average of the markings on treatment AH (H). Within a single replicate of marked treatments (IH, EH, AH and AL) the pattern was the same, with only the contrast level and contrast placement differing. Across replicates, targets were based on different samples of bark, and so each replicate of targets had a unique pattern.