Can predators influence small rodent foraging activity rates immediately after wildfires?

Abstract

Background Habitat complexity, predation risk, and intraspecific competition shape rodent communities and impact foraging. Wildfires remove vegetation shelter, which increases the predation risk perception and leads to changes in trophic resources availability. Consequently, prey adjust their foraging activity levels to minimise the likelihood of encounters with predators. Rodents select safe habitats and can detect predators’ scents, which allows them to reduce the predation risk when foraging. Aims To evaluate the effects of carnivore occurrence and habitat structure on rodent foraging activity rates immediately after fires using mixed models and structural equation modelling. Methods This study used 900-m linear transects to analyse environmental variables, acorn removal by rodents, and carnivore activity in three recently burnt areas. Results In areas with higher stone marten abundances, rodents removed more acorns. However, acorn removal was also higher in structurally complex habitats with greater rodent abundance. Conclusions Rodents’ foraging activity is driven by increased interspecific competition and the predation risk perception due to the simplicity of the burnt habitat. Additionally, stone martens and rodents share the same preferences for habitat complexity after fires. Implications Habitat complexity increases seed holding by rodents, which positively contributes to fire recovery and attracts predators, thereby increasing species diversity.