Data from: Predator response to the coloured eyespots and defensive posture of Colombian four-eyed frogs

Deimatic displays, where sudden changes in prey appearance elicit aversive predator reactions, have been suggested to occur in many taxa. These (often only putative) displays frequently involve different components that may also serve antipredator functions via other mechanisms (e.g. mimicry, warning signalling, body inflation). The Colombian four-eyed frog, Pleurodema brachyops, has been suggested to gain protection against predation through putative deimatic displays where they inflate and elevate the posterior part of their body revealing eye-like colour markings. We exposed stationary artificial frogs to wild predators to test whether the two components (eyespot/colour markings, defensive posture) of their putative deimatic display, and their combination, provide protection from predation without the sudden change in appearance. We did not detect any obvious additive effect of defensive posture and eyespots/colour markings on predation risk but found a marginally-significant trend for model frogs in the resting posture to be less attacked when displaying eyespots/colour markings than when they were not, suggesting that the presence of colour markings/eyespots may provide some protection on its own. Additionally, we found that models in a resting posture were overall more frequently attacked on the head than models in a defensive posture, indicating that a defensive posture alone could help redirect predator attacks to non-vital parts of the body. The trends found in our study suggest that the different components of P. brachyops' coloration may serve different functions during a deimatic display, but further research is needed to elucidate the role of each component when accompanied by sudden prey movement.

恐吓展示（deimatic display）指猎物外观突发变化以引发捕食者厌恶反应的行为，此前被认为在众多动物类群中存在。这类（通常仅为推定的）展示往往包含多种组分，这些组分也可通过其他机制发挥反捕食功能（例如拟态、警戒信号传递、身体膨胀）。哥伦比亚四眼蛙（Pleurodema brachyops）被认为可通过推定的恐吓展示获得反捕食保护：它们会膨胀身体并抬起身体后部，露出类似眼睛的体色斑纹。我们将静止的人工蛙模型暴露于野生捕食者环境中，旨在验证其推定的恐吓展示的两个组分（眼斑/体色斑纹、防御姿态）及其组合，在无需外观突发变化的情况下是否能降低捕食风险。本研究未检测到防御姿态与眼斑/体色斑纹对捕食风险存在明显的叠加效应，但我们发现了一处边际显著的趋势：处于静止姿态的蛙模型在带有眼斑/体色斑纹时，遭受攻击的概率低于无斑纹的个体，这表明体色斑纹/眼斑本身或可提供一定的保护作用。此外，我们发现处于静止姿态的蛙模型的头部遭受攻击的频率整体高于处于防御姿态的个体，这说明仅依靠防御姿态即可帮助将捕食者的攻击转移至身体的非致命部位。本研究的趋势结果表明，Pleurodema brachyops的不同体色组分在恐吓展示过程中或承担不同功能，但仍需进一步研究以阐明当伴随猎物突发移动时，各组分所发挥的具体作用。