Peer Review #1 of "Evolution of switchable aposematism: insights from individual-based simulations (v0.2)"

Abstract

Some defended prey animals can switch on their normally hidden aposematic signals. This switching may occur in reaction to predators' approach (pre-attack signals) or attack (postattack signals). Switchable aposematism has been relatively poorly studied, but we can expect that it might bring a variety of benefits to an aposmetic organism. First, the switching could startle the predators (deimatism). Second, it could facilitate aversive learning. Third, it could minimize exposure or energetic expense, as the signal can be switched off. These potential benefits might offset costs of developing, maintaining and utilizing the switchable traits. Here we focused on the third benefit of switchability, the cost-saving aspect, and developed an individual-based computer simulation of predators and prey. In 88 128 model runs, we observed evolution of permanent, pre-attack, or postattack aposematic signals of varying strength. We found that, in general, the pre-attack switchable aposematism may require moderate predator learning speed, high basal detectability, and moderate to high signal cost. On the other hand, the post-attack signals may arise under slow predator learning, low basal detectability, and high signal cost. When predator population turnover is fast, it may lead to evolution of post-attack aposematic signals that are not conforming to the above tendency. We also suggest that a high switching cost may exert different selection pressure on the pre-attack than the postattack switchable strategies. To our knowledge, these are the first theoretical attempts to systematically explore the evolution of switchable aposematism relative to permanent aposematism in defended prey. Our simulation model is capable of addressing additional questions beyond the scope of this article, and we open the simulation software, program manual, and source code for free public use.PeerJ reviewing PDF | Abstract 44 45 Some defended prey animals can switch on their normally hidden aposematic signals. This 46 switching may occur in reaction to predators' approach (pre-attack signals) or attack (post-attack 47 signals). Switchable aposematism has been relatively poorly studied, but we can expect that it 48 might bring a variety of benefits to an aposmetic organism. First, the switching could startle the 49 predators (deimatism). Second, it could facilitate aversive learning. Third, it could minimize 50 exposure or energetic expense, as the signal can be switched off. These potential benefits might 51 offset costs of developing, maintaining and utilizing the switchable traits. Here we focused on 52 the third benefit of switchability, the cost-saving aspect, and developed an individual-based 53 computer simulation of predators and prey. In 88 128 model runs, we observed evolution of 54 permanent, pre-attack, or post-attack aposematic signals of varying strength. We found that, in 55 general, the pre-attack switchable aposematism may require moderate predator learning speed, 56 high basal detectability, and moderate to high signal cost. On the ...