Data from: Multi-trait mimicry and the relative salience of individual traits

Mimicry occurs when one species gains protection from predators by
resembling an unprofitable model species. The degree of mimic-model
similarity is variable in nature and is closely related to the number of
traits that the mimic shares with its model. Here, we experimentally test
the hypothesis that the relative salience of traits, as perceived by a
predator, is an important determinant of the degree of mimic-model
similarity required for successful mimicry. We manipulated the relative
salience of the traits of a two-trait artificial model prey, and
subsequently tested the survival of mimics of the different traits. The
unrewarded model prey had two colour traits, black and blue, and the
rewarded prey had two combinations of green, brown and grey shades. Blue
tits were used as predators. We found that the birds perceived the black
and blue traits similarly salient in one treatment, and mimic-model
similarity in both traits was then required for high mimic success. In a
second treatment, the blue trait was the most salient trait, and
mimic-model similarity in this trait alone achieved high success. Our
results thus support the idea that similar salience of model traits can
explain the occurrence of multi-trait mimicry.