Sample collection

In the period 2012–2018, we collected fecal samples from red foxes legally hunted or found dead in the provinces listed above, which were given to our laboratories for different purposes (e.g. general diagnostics, rabies surveillance, oral vaccination monitoring, surveillance of Trichinella spp.). For each fox, age (juvenile: foxes < 1 year old; adult: foxes > 1 year old), gender, date and geographical location of the finding/culling were annotated.

Each fox was then georeferenced according to the procedure outlined in Obber et al. [16] (Fig. 1).

In accordance with Boitani et al. [29], each fox was assigned, on the basis of the time of finding, to one of six temporal classes of the biological cycle of the species:

January–February: mating period;

March–April: cubs birth period and early denning period, when cubs remain in the dens or in their immediate surroundings;

May–June: cubs spend time and become visible also outside the dens, seeking food;

July–August: cubs begin to be more independent;

September–October: cubs begin to move out of their family group;

November–December: dispersal period, when cubs move to find, establish and mark a new territory.