Predator‐driven behavioural shifts in a common lizard shape resource‐flow from marine to terrestrial ecosystems

Abstract

AbstractForaging decisions shape the structure of food webs. Therefore, a behavioural shift in a single species can potentially modify resource‐flow dynamics of entire ecosystems. To examine this, we conducted a field experiment to assess foraging niche dynamics of semi‐arboreal brown anole lizards in the presence/absence of predatory ground‐dwelling curly‐tailed lizards in a replicated set of island ecosystems. One year after experimental translocation, brown anoles exposed to these predators had drastically increased perch height and reduced consumption of marine‐derived food resources. This foraging niche shift altered marine‐to‐terrestrial resource‐flow dynamics and persisted in the diets of the first‐generation offspring. Furthermore, female lizards that displayed more risk‐taking behaviours consumed more marine prey on islands with predators present. Our results show how predator‐driven rapid behavioural shifts can alter food‐web connectivity between oceanic and terrestrial ecosystems and underscore the importance of studying behaviour‐mediated niche shifts to understand ecosystem functioning in rapidly changing environments.