Impatto antropico e coesistenza della fauna selvatica: interazioni spaziali tra ungulati selvatici, uomini e lupi nelle Alpi Marittime

Following the gradual abandonment of the Alpine mountains by human populations in the 1960s, wildlife has recovered in both numbers and distribution. The increase in wooded areas and ecotones has improved environmental conditions for the spread of wild ungulates, leading to the return of predators that had previously disappeared due to the absence of prey and unruled culling. As a result, animals with broad ecological plasticity, such as roe deer, have been able to expand their distribution range, overlapping with other species and leading to the development of complex interspecific interactions (e.g., competitive and/or predator-prey dynamics). Nevertheless, man has not completely abandoned the mountain environment, maintaining activities such as farming, hunting and tourism, that must be accounted in the complex interplay between competition and predation. This, together with the necessity of considering the presence of interacting species when modelling communities, has received little attention in previous studies, which have mostly focused on detailed interactions such as those between roe deer and wolves, rather than taking a comprehensive approach to modelling the entire community. This study modelled the co-occurrence probabilities of roe deer, red deer, and wolves in the Maritime Alps using data derived from 57 camera traps, encompassing an area of 136 km2, which have been analysed through multi-species occupancy models. The study aimed to (i) evaluate the role of interactions in shaping inter-specific communities, (ii) explore the impact of human activities on species detection probability, and (iii) investigate the effect of the hunting season on competition and predation relationships using roe deer as the focal species. Among the identified species, roe deer reported the highest frequency of recorded events and was also the most widespread species. The models outputs provided important evidence of interspecific dependence, revealing that pairwise interactions among species had a greater impact than only considering individual environmental effects. Furthermore, the probability of certain species occupying the same site varied along environmental gradients; i.e., the two ungulates are more likely to occur together as the distance from houses decreased. It was also found that the placement of cameras on trails increases the likelihood of detecting wolves but decreases the likelihood of detecting ungulates. Most importantly, the hunting season significantly reduces the likelihood of capturing roe deer, but had no effect on the capture of either red deer or wolves. The results suggest that the use of habitat by wildlife should not only be examined in relation to site-specific variables (e.g., environmental variables such as terrain roughness or forests) because species are in close interaction with each other, and these interactions cannot be overlooked. Similarly, humans resulted to exert a significant influence on shaping the community, especially when considering hunting, which further modifies the dynamics. This study provides important insights into species interactions in the human-dominated landscape of the Western Alps, confirming the relevance of including prey, predators, and human dynamics as a whole. The findings have significant implications for guiding management decision and for indicating good practices to minimize human impacts for developing sustainable approaches in complex predator-prey systems.