Recent surveys have shown that in Albania otters occur on rivers which had been judged unsuitable in the 1980s, pointing out the need for further investigations. We assessed otter distribution on a 60 km long stretch of the River Drinos, a major tributary of the River Vjosa. Marking intensity was assessed in two seasons, spring and summer 2010, corresponding to the highest and lowest river discharge levels, respectively. Otter signs (spraints and jellies) were searched for along 300 river stretches 200 m long (sampling stations). Vegetation coverage, hydraulic pattern and human disturbance were assessed visually for the whole length of each sampling
station. Both the mean number of sprainting sites and otter signs per 200 m of watercourse were higher in spring (0.81 and 2.6, respectively) than in summer (0.55 and 1.25). In spring otter signs were recorded in 118 sampling stations (39 %), while in summer, when the first 24 km of the watercourse were completely dried up, 92 sampling stations were positive for otters (31 %). Considering only the permanent river course, the variation in otter distribution was less marked (58 % vs. 51 % of 181 sampling stations). According to previous studies, the number of sprainting sites was correlated to vegetation cover, whilst variation in the hydraulic pattern of the
permanent river stretch did not influence marking intensity. Our results suggest that pollution control and habitat restoration can favour otter expansion in the river plains of central and southern Albania.
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.