Anti-predator mechanisms play a key role in the survival of any animal in nature. Anurans exhibit a great diversity of defensive behaviours and interact with the widest range of predators of any vertebrates. However, there are few systematic and experimental studies of anuran defensive behaviours, which are generally opportunistic. Here, we deploy a range of methods to investigate various facets of anuran defensive behaviour using the cane toad Rhinella marina as a model organism. This originally Amazonian anuran is now widely distributed across the globe and has caused several predators to decline at introduction sites where this species is not native, a direct result of its anti-predation defenses. First, we compiled previously published data on anuran predation events to assess the relationship between predator/anuran size and predator size and type. We then performed a systematic experiment to test the hypothesis that there is an ontogenetic variation in cane toad behavioural defense displays, as well as a variation in these displays between males and females. In total, we tested 173 individuals including juveniles, adult males and adult females. We show that the size and type of the predator is related to the size of the anuran as prey and that this, in turn, has led to the adoption of different predation-avoiding behavioural defensive strategies during ontogeny. Our results also indicate that both the sex and the size of anurans influence the adoption of defensive strategies.

反捕食者机制在自然界中任何动物的生存中都发挥着关键作用。Anurans 表现出多种多样的防御行为，并与任何脊椎动物中最广泛的捕食者相互作用。然而，关于anuran防御行为的系统性和实验性研究很少，这通常是机会主义的。在这里，我们部署了一系列方法来研究使用甘蔗蟾蜍Rhinella marina的 anuran 防御行为的各个方面作为模式生物。这种最初的亚马逊anuran现在广泛分布在全球各地，并导致一些捕食者在该物种不是本地的引入地点减少，这是其反捕食防御的直接结果。首先，我们汇编了之前公布的关于无尾龙捕食事件的数据，以评估捕食者/无尾龙大小与捕食者大小和类型之间的关系。然后，我们进行了一项系统实验，以检验甘蔗蟾蜍的行为防御表现存在个体发育变异以及雄性和雌性之间这些表现存在差异的假设。我们总共测试了 173 人，包括青少年、成年男性和成年女性。我们表明，捕食者的大小和类型与作为猎物的无尾巨蜥的大小有关，而这反过来，导致在个体发育过程中采用不同的避免捕食的行为防御策略。我们的研究结果还表明，anurans 的性别和大小都会影响防御策略的采用。