Wild felids in trophic cascades: a global review

Abstract

Carnivores, often identified as keystone species, can influence prey and subordinate carnivores through density‐ and behaviourally mediated pathways. Although the magnitude of their impacts remains debated, carnivores may trigger successional direct and indirect ecological effects on lower trophic levels in specific contexts, commonly known as trophic cascades. Felids, as ambush predators, have great potential to impact food webs. Yet, their influence on ecosystem dynamics remains understudied. This global comprehensive literature review aimed to assess evidence for felids' ecological roles in trophic cascades across both natural and human‐dominated ecosystems. We found 61 publications that studied the influence of 18 felid species in trophic cascades. Research exhibited taxonomic and geographic biases, favouring big cats, temperate regions and biomes, as well as tropical moist forests in Central and South America. Of the studies, 23% (n = 14) were experimental, while 77% were observational or correlative. Among the latter, 60% tested at least one alternative hypothesis and 47% examined bottom‐up processes. Despite varying levels of inference, 80% of studies provide information consistent with trophic cascades involving felids. Their examination confirmed wild cats' ability to induce density‐ and behaviourally mediated trophic cascades, thereby influencing critical biotic and abiotic processes, including mesopredator control, functional diversity maintenance, and carbon storage. The magnitude of these effects may be altered in human‐dominated landscapes, although current research effort remains too limited to draw conclusions. In conclusion, felids may act as drivers of ecosystem change, and acknowledging their ecological roles can aid in promoting their conservation. However, we encourage more strongly inferential and comprehensive investigations into felid‐mediated trophic cascades, prioritising research on small cats, felids in Asia and Africa, and the impacts of humans on trophic cascades, which can help to better inform conservation interventions and perspectives.