LAUSR

Aposematic signals, such as bright colour patterns, are conspicuous warnings that indicate the unprofitability of a prey item to a potential predator (Wallace, 1867). Conspicuous warnings frequently incorporate colours such as red, orange and yellow, and also often include bold patterns incorporating black that result in high contrast (reviewed in Ruxton, Sherratt, & Speed, 2004). While conspicuous coloration may bring attention to the aposematic animal, theory suggests that learned and innate aversions to the signal (and to the defences that accompany it) should keep predators from attacking (reviewed in Guilford, 1990; Mappes, Marples, & Endler, 2005; Merilaita & Ruxton, 2007; Skelhorn, Halpin, & Rowe, 2016; Stevens & Ruxton, 2012). However, in complex interactions in nature, aposematic signals do not always provide universal protection and predators may make strategic decisions to attack, and even consume, prey containing various degrees of toxin (e.g. Barnett, Bateson, & Rowe, 2014; Brower & Calvert, 1985; Burdfield-Steel, Schneider, Mappes, & Dobler, 2020; Calvert, Hedrick, & Brower, 1979; Halpin, Skelhorn, & Rowe, 2014; Hristov & Conner, 2005; Rojas et al., 2017; Sherratt, 2003; Skelhorn & Rowe, 2007). To further our understanding of the evolution and maintenance of aposematism, it is important Received: 11 May 2020 | Revised: 24 July 2020 | Accepted: 15 August 2020 DOI: 10.1111/eth.13089