Crouching lion & coursing hyaenas: Which one zebras are more afraid of?
Predators and their prey have complex relationships that are influenced by a range of factors. Each predator species has its own preferences for what prey to eat, which can be affected by its size, sociality, habitat, season, and more. Over the past two decades, the Landscape of Fear concept has helped us understand these relationships better. The idea behind this concept is that the fear of predation can shape the behaviour of prey animals and influence their distribution and movement patterns in the environment. This, in turn, can also affect the behaviour of predators, as they may avoid areas where prey animals are difficult to catch or where they are at risk of injury.
While there is evidence that the preferred prey of a given predator species responds more strongly to the risk of predation by this species compared to other carnivores, there has been a lack of studies looking at the effects of predators’ hunting tactics on prey response. Ambush predators, such as lions and leopards, remain still and wait for their prey to come within striking distance. They rely on stealth and camouflage to surprise their prey and attack with a quick burst of speed. In contrast, cursorial predators, such as spotted hyaenas and African wild dogs, actively chase and pursue their prey over a distance. They are usually faster and more agile than their prey, relying on speed, endurance, and manoeuvrability to catch their targets. The main difference between the two types of predators is their approach to hunting. Ambush predators rely on stealth and surprise, while cursorial predators rely on speed and agility. Additionally, ambush predators tend to have a sit-and-wait strategy, while cursorial predators are active hunters that roam their territory in search of prey.
Understanding the effects that these different hunting strategies have on prey is crucial for our understanding of complex ecosystems’ functioning and for their effective conservation and wildlife management.
In an effort to fill this knowledge gap, we focused on understanding how plains zebras reacted to encounters with lions and spotted hyaenas in Hwange National Park, Zimbabwe. We used GPS data from collars simultaneously deployed on the three species to identify when and where they encountered each other and decipher how zebras moved after these encounters.
We expected lions, as larger and ambush predators are expected to be perceived as more dangerous and hence to induce a stronger reactive spatial response than hyaenas.
Our study revealed that zebras did respond differently, and more strongly, to lions and hyaenas. The zebras were twice as likely to flee after encountering a lion than after encountering a hyaena. Additionally, when zebras moved away from the encounter, they did so on average faster and further after encountering a lion compared to encountering a hyaena.
However, there was a lot of variability in these behavioural patterns. The response to encounters was very context-specific and also likely to be affected by zebras’ group size, the carnivore group's size and composition, their behaviour, and the encounter's location. For example, zebras in larger groups are safer from predation, so they might decide to stay longer or move shorter distances than zebras in smaller groups. The risk represented by facing a group of 3 lionesses versus a group of 4 lionesses with their sub-adult offspring and pride males is not the same. Similarly, encountering a group of hyaenas feeding on a carcass poses much less of a threat than encountering them when they are patrolling their territory, looking for prey. Lastly, being water-dependent, moving away from encounters close to a waterhole is more costly for zebras, especially if they were on their way to drink.
In conclusion, our research contributes to the growing body of knowledge on how prey respond to encountering predators, highlighting the importance of context in shaping these responses. Our findings also shed light on the potential for multi-predator effects, where the presence of one predator can affect the distribution and behaviour of other predators and their prey. Specifically, we observed that lion presence could lead to a decrease in prey density for hyaenas (since zebras move away from these areas), while at a larger spatial scale, it may benefit them by increasing the likelihood of encounters with zebras (as zebras are more likely to move after encountering lions). We hope that future studies in different ecosystems and with other predator species will help us better understand how predator attributes, such as body size and hunting mode, impact prey antipredator responses.
This study was led by Elise Say-Sallaz, a PhD student (and now a Doctor) from the CNRS lab of Biometry and Evolutive Biology in Lyon, under the supervision of Dr Marion Valeix and was published in Animal Behaviour. You can read the full publication here: Large carnivore dangerousness affects the reactive spatial response of prey.