Prey movement, size, and glossiness interact to impact praying mantid attack behaviors

When moving, animals are vulnerable to predation because movement can rapidly attract the attention of a predator. To reduce the risk of predation while moving, animals can use a variety of different strategies (eg erratic movement, coloration). These strategies often work in combination or may be influenced by other prey characteristics (eg size), but few studies have explored these interactions. Here, we investigate how movement trajectory (linear or erratic), prey size (small or large) and prey coloration (glossy or matte) interact to impact the attack behavior of giant rainforest mantids (Hierodula majuscula). We presented mantids with animations of moving targets and filmed their response with a high-speed camera. As expected, mantids were more likely to track large than small targets and targets moving linearly than erratically. Counterintuitively, however, mantids were quicker to strike at erratically moving targets, perhaps because they more closely resembled preferred prey. When mantids attacked the target, their accuracy was influenced by the interaction of target trajectory and glossiness. As predicted, mantids had larger attack errors (ie lower accuracy) toward erratically moving glossy targets compared with linearly moving glossy targets or erratically moving matte targets. However, contrary to our prediction that linearly moving matte targets would be easiest to capture, these targets also elicited large attack errors, similar to those recorded for erratically moving glossy targets. Together, our results demonstrate that anti-predator tactics for prey in motion may interact in complex ways, and simple experimental scenarios may overlook context-dependent effects that emerge when multiple factors interact.