The characteristics and density of Eurasian badger Meles meles setts and the factors affecting sett-site choice were studied from February 1999 to January 2000 in the River Po Park (Piedmont region, NW Italy). Badger setts were a complex of underground tunnels with, on average, 6.4 entrances. In hilly habitat badger sett density was higher than in lowlands (1.32 vs. 0.21 setts/km2) as well as the mean number of entrances per sett (11.5 vs. 3.5). These data were similar to those recorded in many other European areas with low badger population density. In our study area, badgers clearly selected tree-cover (woods and shrubs), also tolerating human disturbance. In a widespread plain area, where the original forest vegetation has been dramatically reduced, sett sites were concentrated in residual wood belts along the slopes of alluvial terraces or in scrubs growing on artificial embankments. This study confirms the badger as a highly adaptable species that can exploit different habitats. Nevertheless badger populations living in predominantly agricultural lands depend on habitats offering sufficient cover for their breeding sett location. The improvement of natural vegetation cover is essential for the future conservation of badger populations in Po plain landscapes.
From September 1994 to August 1995 we studied the diet of coypus, Myocastor coypus, in a freshwater habitat located in the Ticino regional park (NW Italy). Adult and young coypus were directly observed foraging in and near water. Aquatic macrophytes (81.8%) represented the staple food all year round. Common reeds (Phragmites australis) and Elodea spp. were the main components of the overall diet. A complementary seasonal consumption of submersed/floating-leaved macrophytes and emergent macrophytes was observed, the former ones reaching the highest value in summer (65.7%) when the latter ones were at their minimum (16.2%). Differences in diet composition of adult and young coypus were recorded in summer, when adults consumed more submersed/floating-leaved plants (mainly Callitriche stagnalis and Myriophyllum spicatum) and young coypus more terrestrial plants, predominantly black locust Robinia pseudoacacia leaves. Terrestrial vegetation was a usual integrative resource of the coypu diet all year round, particularly for young coypus in summer. Slight damage to the plant community was observed in small areas over-grazed by coypus. Nevertheless, 7 out of 12 threatened Italian hygrophilic species were eaten by coypus, suggesting that particularly sensitive aquatic plants could suffer from long–term foraging. Selective control of coypus in natural ecosystems of particular conservation concern is suggested, in order to limit damage to native plant communities of freshwater habitats.
To investigate time- and spatial related variations in the composition of otter Lutra lutra diet, a total of 838 faecal samples was collected in the upper catchment of the Agri River (Basilicata region, southern Italy), and analysed. Data were split up according to the four seasons and between the main river and three of its tributaries. Fish and amphibians formed the bulk of otter diet, their consumption being inversely correlated. Trophic niche breadth was positively correlated with the frequency of occurrence of fish, whilst it was negatively correlated to that of amphibians and the altitude of the sampling stations. The frequency of consumption of fish did not vary through the year, whilst amphibians were mainly eaten during their hibernation and breeding period. Otter diet along the four main rivers differed significantly, the species being mainly piscivorous on the main river, whilst relying on alternative food resources on its tributaries, where habitat features or human interference reduced fish abundance. Fish availability seems to represent the main factor determining the composition and diversity of otter diet.