While foraging, it is critical for a predator to detect and recognize its prey quickly in order to optimize its energy investment. In response, prey can use low-cost energy strategies such as crypsis and immobility that operate early in the detection–attack sequence. Mesopredators, such as spiders, are themselves attacked by visually oriented predators such as mud-dauber wasps. However, it is not known which colour cues are used by wasps to detect and capture their spider prey or whether there are biases towards such cues. In this study, we evaluated the prey colour biases of two mud-dauber wasps (Trypoxylon tridentatum and Trypoxylon bridwelli) using full-spectrum digital photography and visual modelling. We compared the colour contrast of spiders that were preyed upon with that of the spiders in the surrounding habitat. We show that the spiders captured by the wasps had higher chromatic contrast with their typical backgrounds compared with other co-occurring spider species not found in Trypoxylon nests. Our results suggest that Trypoxylon wasps may exhibit colour biases and/or preferences when hunting their spider prey. Our study highlights the importance of considering the perceptual abilities and biases of predators when studying predator–prey interactions.

在觅食时，捕食者快速检测并识别猎物以优化其能源投资至关重要。作为响应，猎物可以使用低成本能量策略，例如在检测攻击序列的早期进行的低温和固定化。中蜘蛛，例如蜘蛛，本身会受到肉眼可见的掠食者的攻击，例如泥巴黄蜂。但是，尚不知道黄蜂使用哪种颜色提示来检测和捕获其蜘蛛猎物，或者是否对这种提示有偏见。在这项研究中，我们评估了两种黄泥黄蜂（Trypoxylon tridentatum和Trypoxylon bridwelli）的猎物颜色偏差）使用全光谱数码摄影和视觉建模。我们比较了被捕食的蜘蛛和周围栖息地的蜘蛛的颜色对比。我们显示，与在Trypoxylon巢中未发现的其他同时出现的蜘蛛物种相比，被黄蜂捕获的蜘蛛在其典型背景下具有更高的色差。我们的结果表明，Trypoxylon黄蜂在猎取蜘蛛猎物时可能会出现颜色偏差和/或偏爱。我们的研究强调了在研究食肉动物与猎物之间的相互作用时，要考虑到食肉动物的感知能力和偏见的重要性。