New drivers of the evolution of mimetic accuracy in Batesian mimics: body size, habitat stratification and geographic zone affect accuracy of myrmecomorphic spiders

Aim: The evolution and maintenance of accurate Batesian mimicry has been explained by several hypotheses built upon relaxed selection. Such selection can be influenced by ecological factors, such as habitat type or geographic distribution, which have not been considered. I investigated whether the mimetic accuracy is influenced by habitat stratification where mimics occur (ground, low vegetation, bush, tree), their body size, and geographic distribution (temperate, subtropical, tropical).

Location: Worldwide

Taxon: Araneae

Methods: I gathered data on body size, geographic area of distribution, and habitat stratification from literature on more than 400 ant-mimicking (myrmecomorphic) spider species from 18 spider families and ranked them into four accuracy levels based on morphology, from poor inaccurate mimics to very accurate ones. Then I used regression to study the effect of body size, distribution, and habitat on mimetic accuracy while controlling for phylogeny.

Results:...