Aposematic organisms are often unprofitable to predators (e.g. because of defensive chemicals) which they advertise with a conspicuous signal (e.g. bright and conspicuous colour signals). Aposematism is thought to reduce predation of prey because the colour signal increases the ability of predators to learn, recognize and remember the prey’s defensive properties. The efficacy of aposematism has been extensively documented in laboratory studies, although its benefits seem to be harder to demonstrate in the field. In this study, we compared the levels of partial and overall predation among four prey types (undefended and cryptic, undefended and warning coloured, defended and cryptic, and aposematic prey). Overall, predation of warning coloured and defended (aposematic) prey was lower than the predation for cryptic and undefended prey; however, it was the same as predation of cryptic and defended prey. Moreover, aposematic prey had higher levels of partial predation (where prey was not wholly consumed by the predator) and lower attack intensities. This suggests that prey were being taste sampled, but also might be better able to survive attacks. Therefore, the benefits of aposematism may lie not only in reducing outright predation, but also in altering a predator’s post-attack behaviour, thus leading to greater escape opportunities and post-attack survival of prey. These results reinforce the importance of examining predation in more detail rather than simply examining attack rates.

中文翻译：

---

事实是细节：捕食者以比其他猎物更少的侵略性攻击姿势性猎物

惯常性生物通常对掠夺性动物（例如由于防御性化学物质）无能为力，它们以明显的信号（例如明亮和明显的颜色信号）做广告。由于颜色信号增加了捕食者学习，识别和记住猎物的防御能力的能力，所以认为放任会减少猎物的捕食。尽管在临床上难以证明其益处，但在实验室研究中已经广泛记录了它的功效。在这项研究中，我们比较了四种猎物类型（不设防和隐秘，不设防和警告色，设防和隐秘以及无目的猎物）的部分和整体捕食水平。总体而言，有色人种和防御性（惯常的）猎物的捕食活动要低于隐秘和不设防的猎物的捕食活动。然而，它与神秘的和防御的猎物一样。此外，姿势性猎物的部分捕食水平较高（在这种情况下，捕食者并未完全消耗猎物），攻击强度较低。这表明正在对猎物进行品尝，但也可能更好地抵抗攻击。因此，放牧的好处不仅在于减少彻底捕食，而且在于改变捕食者的攻击后行为，从而导致更大的逃脱机会和攻击后的生存。这些结果加强了更详细地检查掠夺的重要性，而不是简单地检查攻击率。这表明正在对猎物进行品尝，但也可能更好地抵抗攻击。因此，放牧的好处不仅在于减少彻底捕食，而且在于改变捕食者的攻击后行为，从而导致更大的逃脱机会和攻击后的生存。这些结果加强了更详细地检查掠夺的重要性，而不是简单地检查攻击率。这表明正在对猎物进行品尝，但也可能更好地抵抗攻击。因此，放牧的好处不仅在于减少彻底的捕食，而且在于改变捕食者的攻击后行为，从而导致更大的逃避机会和攻击后的生存。这些结果加强了更详细地检查掠夺的重要性，而不是简单地检查攻击率。