When face to face with a predator, would you rather have blistering speed to out-run or fancy footwork to out-manoeuvre your foe? If you opted for speed, you're not alone. We intuitively think quicker means better when it comes to eluding capture. Our fascination with fast is so pervasive that most research on predation and prey evasion focuses solely on maximal speeds when evaluating performance. But, are we missing an important part of the predator–prey story? Christofer Clemente and Robbie Wilson from the University of Queensland, Australia think so. In fact, they suggest that when it comes to gauging success in escaping from predators, our thinking needs a change in direction.
Clemente and Wilson wanted to explore the role of traits other than speed in determining whether a victim escapes from a predator unscathed. They decided to focus on manoeuvrability; the capacity to turn rapidly within a confined space (i.e. with a small turning radius). Unfortunately, studying animal twists and turns has taken a backseat to speed in most research to date for one very practical reason: manoeuvrability is a hard thing to quantify and measure, especially in free-living animals. To overcome these logistic challenges, the team had to think outside the box. They designed a tablet-based game to simulate encounters between on-screen ‘prey’ dots and the ultimate food- (and technology-) motivated predators: university students. The team manipulated the behaviour of a single prey dot moving left to right across the screen by programming differences in prey speed, size and directional changes (manoeuvres) into discreet trials. To capture the prey and end the trial, the human predator had to tap on the moving dot within a certain radius of accuracy. After thousands of trials on dozens of volunteers, the researchers were able to evaluate what combinations of prey size, speed and manoeuvrability fared best when facing the touch of death.
If you initially opted for speed over foot-work in the thought experiment above, don't fret: Clemente and Wilson confirmed the importance of being fast when it comes to escape success. However, their results also suggest that for slow prey, manoeuvrability can be the difference between escaping or ending up as dinner. The interaction between speed and manoeuvrability is even more complex when considering body size. Larger prey were hugely disadvantaged when travelling at intermediate speeds compared with smaller prey. Yet, body size did not seem to interact with manoeuvrability to determine escape success: more manoeuvrable means more likely to escape across all prey sizes. The researchers note that smaller animals such as mice and lizards, which have relatively slow absolute speeds, also tend to be highly manoeuvrable.
Clemente and Wilson's research stresses the need to move beyond the current focus on speed when it comes to predicting the outcomes of predator–prey interactions. Understanding the role of traits like manoeuvrability, as well as acceleration and predictability, may provide a more complete picture of how some individuals thwart the hunt. Despite all this complexity surrounding escape success and performance, one clear pattern emerges: slow and steady definitely does not win the race!
- © 2015. Published by The Company of Biologists Ltd