Different environmental contexts, different responses: Evaluating the drivers of red fox occupancy patterns in Portugal

Identifying the drivers and ecological mechanisms that shape species occupancy patterns at large scales is decisive in understanding how species respond to environmental changes. In this study, we compiled camera trapping data from different scientific projects and monitoring programs to conduct the first assessment of the relevant ecological drivers of red fox ( Vulpes vulpes ) occupancy patterns at the national level in Portugal. Here, using single-species/single-season occupancy models, we target two regions with different environmental contexts - north and south of River Tagus. Our results show that the red fox occupancy drivers change depending on the environmental context. In the northern region (more mountainous and densely forested), occupancy patterns were mostly shaped by direct human-associated disturbance, positively associated with dogs’ relative abundance index. On the other hand, in the southern region (plain areas dominated by agroforestry systems), the variation in red fox occupancy patterns was best explained by the habitat characteristics, with foxes showing a higher probability of occupying areas with greater habitat diversity. Considering these results, we conclude that the red fox’s generalist character is highlighted by its capacity to adopt two different occupancy strategies depending on the environmental context: the use of more humanized areas, along with free-ranging dogs, in the Northern region, and the use of areas with more diversified resources in the Southern region. Therefore, our study reinforces the red fox's highly adaptive character, adding crucial information to tailor red fox management and conservation actions to the different regional environmental contexts of Portugal.