Staying safe from top predators: patterns of co-occurrence and inter-predator interactions

Abstract

Top predators often have cascading effects on mesopredator communities by driving behavioural changes. Using camera-trapping surveys, we explored the site-detection probability of sympatric predators and temporal overlap and examined behavioural patterns to explore hypotheses of carnivore guild interactions between and within large and small predators in the presence/absence of lion (Panthera leo) in open and closed habitat cover. We used single-season two-species occupancy models to test inter-predator interactions at 205 camera sites spread across five Protected Areas of the Maputaland Conservation Unit, South Africa. These data showed the respective associations between the presence of large carnivores and smaller carnivores. We observed that leopard (Panthera pardus) and hyena (Crocuta crocuta) tended to avoid interference encounters, as they were less likely co-detected at the same sites. There was a decrease in detection of leopard and hyena as a function of lion presence. Small predators such as the group honey badger (Mellivora capensis)-striped polecat (Ictonyx striatus) and the slender mongoose (Herpestes sanguineus) were detected less often at cameras where leopards were detected. Detection probabilities of the group badger-polecat and slender mongoose were much higher in the closed habitat than in open habitat where leopards were detected. At camera sites where hyenas were detected, badger-polecat and genet (Genetta tigrina) detection probability was much higher in the closed habitat than open habitat. Slender mongoose overlapped less temporally with large predators while others did not. Our study showed that large predator guilds can affect the probability of detecting subordinate mesopredators; therefore, reintroduction of large carnivores can have a cascading effect on subordinate carnivores, and it is necessary to consider this effect when planning recovery programmes for carnivore conservation. We think this study is of importance and interest as top predators often shape mesopredator communities by inducing apparent avoidance behaviour based on associations between the presence of large carnivores and smaller carnivores. As a consequence, smaller predators use closed habitat to minimize the risk of larger predators due to intraguild interference interaction. We explored behavioural patterns of sympatric predators’ site detection probability and temporal overlap and examined hypotheses about carnivore guild interactions between leopard and spotted hyena, these two and small predators with and without lion in open and closed habitat cover. Reintroduction of one carnivore population can have cascading effects on the other, and this nature of consequences needs to be accounted when planning conservation or species recovery programmes. Therefore, we extended our study to explore these important aspects. Our study is novel as there are no studies documenting species interactions between/within large and small predators from co-occurrence patterns in South Africa.