Vertebrate community responses to the Vaia windstorm: from species richness to spatio-temporal behavioral shifts

Extreme weather events, such as windstorms, are among major forest disturbances and entailsignificant changes in ecosystem structures and wildlife population dynamics. Understandingcommunity-level responses to such disturbances is vital not only for informed conservationstrategies, but also to assess the potential drivers of disease dynamics. This study investigatedthe mid-term impact of the 2018 Vaia windstorm on the species richness, abundance and activityof vertebrate communities in the Paneveggio-Pale di San Martino Natural Park (Trento, Italy).Using a standardized camera-trapping design, we monitored two altitudinal levels: Val Canali(1.100 m a.s.l.) and Paneveggio (1.700 m a.s.l.). At each site, 20 camera traps were deployed forone-month in late spring of 2023 and 2024. By applying a control-impact design, we quantifiedspecies richness, relative abundance index (RAI), and spatio-temporal activities by comparingwindthrow-affected (‚Vaia‘) versus undisturbed (‚no-Vaia‘) habitats.Our findings indicated that natural disturbances enhance species richness by increasingenvironmental heterogeneity, providing novel refugia and foraging opportunities. Specifically,red deer (Cervus elaphus) and Alpine chamois (Rupicapra rupicapra) showed higher abundances inwindstorm-affected sites, likely benefiting from increased resources from pioneer vegetation.Conversely, roe deer (Capreolus capreolus) abundance declined in these areas, suggesting asensitivity to altered forage quality, habitat structure or new interspecific interactions withsympatric species. Habitat specialists, including martens (Martes sp.), hares (Lepus sp.), andgrouse, remained strongly associated with undisturbed forests. Among carnivores, red foxes(Vulpes vulpes) were more frequent in Vaia-affected habitats, while wolves (Canis lupus) showedno significant spatial preference. Most species exhibited temporal niche partitioning, avoidingdisturbed open areas during midday and peaking at dawn and dusk. This behavioral shift likelyrepresented a trade-off between thermoregulation and foraging, while simultaneously beingshaped by potential interspecific and human-wildlife encounters.This study underscores the complex, species-specific responses of vertebrate communities toextreme weather disturbances, like the Vaia windstorm. These changes might have implicationsnot only for ecosystem resilience, but also for public health related issues for the role thatvertebrate communities play in disease dynamics. We argue that future monitoring mustintegrate biodiversity indices with systematic pathogen surveillance.We acknowledge the Unione Nazionale Cacciatori Zona Alpi (UNCZA) for their support and forproviding the essential technical equipment for this research.