Abstract: The effects of geographical factors, such as latitude and altitude, on climate are known to influence the food habits of predator species distributed over a broad distribution range. A sharp latitudinal gradient in the diet of the Eurasian otter (Lutra lutra (L., 1758)), that is an increase of trophic diversity from temperate to Mediterranean Europe, has been described recently. Altitude, affecting the diversity of fish assemblages and hence prey availability for otters, could also be a key factor influencing otter diet. With the aim of testing for the presence of an altitudinal gradient in otter diet in the Mediterranean area, we assessed the composition of diet at 24 sampling reaches spread in three main river catchments of southern Italy. The analysis of 1885 spraints revealed that fish were the main prey of otters, followed by amphibians, while other food items were of lesser significance, although crustaceans could be locally important. The altitude of the sampling station was negatively correlated with fish consumption and positively correlated with otter trophic diversity; at higher altitudes, alternative prey (particularly amphibians) were included in otter diet. The reduction of fish availability with elevation plays a major role in shaping this dietary pattern. The ability of otters to exploit alternative prey, such as amphibians, could allow the colonization of small rivers sustaining a low fish biomass.
Abstract: Diet composition of otters (Lutra lutra) was investigated in 2001 by spraints analysis (N ¼ 1323) on ï¬ve rivers of southern Italy, with the aim of assessing the inï¬uence of ï¬sh availability, elevation and discharge on the consumption of food resources alternative to ï¬sh. Data were expressed as per cent frequency of ccurrence (%FO) and per cent volume (%V). The study conï¬rmed the great feeding adaptability of the otter that, in rivers partially interconnected and ï¬owing on a small area, showed a strong ï¬sh eating habit in some rivers (Sinni and Mercure-Lao) and a diet mainly constituted by alternative resources in other ones (amphibians in the rivers Cogliandrino and Frido, crustaceans in the River Battendiero). Fish consumption for the ï¬ve rivers was signiï¬cantly correlated with ï¬sh biomass and with mean summer discharge, while it was inversely correlated with the mean altitude of the ï¬ve rivers. The lack of a clear seasonality in the consumption of food sources alternative to ï¬sh together with the correlation between ï¬sh use and ï¬sh biomass for each river indicated ï¬sh availability as the main factor affecting otter relying to non-ï¬sh preys. Otter diet seemed inï¬uenced by the characteristics of river habitats (altitude, discharge and consequently ï¬sh biomass) more than by summer drought, typical of Mediterranean regions. The %FO and the %V allowed to drawn a similar picture of otter diet. Nonetheless the %V was useful for better illustrating diet variation among the different rivers and we argue that it could be useful in habitats where the otter feeds on preys with different proportions of indigestible remains.
Abstract: In an Alpine area, scat analysis and marking activity were used to assess the feeding habits, habitat preference and the degree of overlap of trophic niche and habitat use in sympatric carnivores: the red fox (n5133 faecal samples), the badger (n5177), the pine and the stone marten (Martes sp., n5382). Fruits were the main trophic resource for all species. The diet of martens differed from those of the red fox and badger by means of a higher consumption of garbage and non-Rosaceae
fruits. The red fox preyed on more lagomorphs and roe deer and relied almost exclusively on two fruit species, rose-hips and whitebeam berries. Badgers ate few invertebrates, with cultivated fruits and pine seeds forming the bulk of their diet. On the whole, trophic niche overlap was kept low by the exploitation of different species of berries and mammals and, secondly, by seasonal differences in the use of same items by the three carnivores. Badger trophic niche overlapped to a wider extent than those of the other two predators in summer, when fruit availability is higher. Foxes used all habitats according to their availability, except for villages, which were avoided. Badgers used mainly open habitats, particularly Alpine meadows, avoiding villages and mixed woods. Martens selected the habitats avoided by the other two predators and avoided all the others. The narrow range of habitat used by martens and diet evidence suggest that, within the context of interspecific competition, they could play the role of sub-ordinate species, segregating in fox-free urban environments.
Abstract: Management of recolonising species needs precise knowledge concerning those environmental parameters that can inï¬uence the species current distribution at the margins of their range and their potential for further expansion. The otter (Lutra lutra) is one of the most endangered species of the Italian fauna. After a sharp decline, it has gradually recovered and, at present, it is conï¬ned to southern Italy. At the southern boundaries of the Italian otter range, the inï¬uence of two geographic
and 15 habitat variables on otter distribution (estimated by 1-year monitoring of 18 spraint-sampling stations) was assessed, to improve management efï¬cacy. Latitude represented the main source of variation in the spraint-collection data. The species was in fact well established in central and northern areas, whereas the southern and western sampling stations showed an unstable river occupancy (the average percentage of positive surveys being 94.5 and 35.8%, respectively;U=0, P = 0.0014). Secondarily, otter relative abundance was positively associated with the degree of cover of aquatic macrophytes. Our results suggest that the whole analysed hydrographic network offers a suitable habitat for otters. Thusweargue that the discontinuous distribution observed in our study area could be a consequence of the sharp decline suffered by the Italian otter populations
during the 1970s and 1980s. The positive trend of the last decades has resulted in the progressive recolonisation of empty habitat patches, a process that is still hindered by the lack of connectivity to extant populations. Ourï¬ndings have implications for landscape restoration projects, suggesting that provision of suitable habitat alone may not be sufï¬cient to effect recolonisation by some species.
Abstract: In central and southern Europe, the red fox Vulpes vulpes is considered the reservoir of the parasite nematode Trichinella britovi, whose mainly fox-to-fox transmission would involve cannibalism in mountainous areas. Reviewing available literature, we examine the main ecological features of the host-parasite relationship, pointing out those aspects which do not agree with the currently accepted epidemiological pattern and requiring further research
Abstract: 1. Changes in otter Lutra lutra distribution in Italy were examined by analysing geographical, historical and survey data.
2. As in other European countries, otters declined sharply in Italy during the late 1970s and throughout the 1980s. Between 1985 and 2004 the species became extinct, except for some reintroductions, in northern and most of central Italy while the species appears to have substantially recovered in its southern range. This recovery of the otter population is apparently not due to increased research effort, but reflects a real expansion of range.
3. Differences in the degree of range reduction during the second half of the 20th century and in the availability of suitable habitats are probably the major factors that have determined the two opposite trends shown by otter populations in the last 20 years.
4. Better knowledge of otter status and distribution is needed for effective conservation management. We suggest that a national survey of the Italian otter population that employs genetic approaches should represent a first step of the national action plan for otter conservation.
Abstract: During the summer 2002-2003, mist-netting at seven cave entrances enabled a survey of cave-dwelling bats in the southern Ticino Canton (Switzerland). Overall, 36 individuals belonging to 7 species were recorded: Rhynolophus ferrumequinum, Hypsugo savii, Plecotus austriacus, P. auritus, Myotis nattereri, M. daubentoni and M. bechsteinii. On average, the percentage of positive surveys was 55.6%. The low number of trapped bats, the high preponderance of males and the low number of recaptures suggest that in the study area caves play a minor role as summer day- and/or night-roosts
Abstract: The food habits of both weasels and stoats (Mustela nivalis and M. erminea) and the occurrence of fruit in their diet were studied by scat analysis in the Gran Paradiso National Park (western Italian Alps). Being impossible to distinguish between stoats and weasels scats, they were grouped together as the genus Mustela. Despite the high consumption of small rodents, which represented the main food item in the diet of small mustelids (41.5% in mean volume), wild fruits (mainly Rosaceae and Ericaceae) were also relatively common (23.3% in mean volume). Fruits were exploited throughout the year, with an intensive use in seasons of high availability. Their consumption did not significantly differ between habitat types, despite a significant decrease of fruit availability from deciduous mixed forest to alpine prairie. This evidence suggests that this trophic behaviour could represent a consolidated feeding strategy of both weasels and stoats, which seem to adopt an opportunistic behaviour as shown by larger size mustelids. We argue that fruits, owing to their good availability and high profitability, could play an important role in the diet of small mustelids in alpine habitats, slackening their well-documented dependence on rodents.
Abstract: 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
Abstract: Population size of European otters (Lutra lutra) was estimated in Pollino National Park (southern Italy) by genetic typing of fresh feces collected in the field. Of 187 fecal samples gathered, 185 (98.9%) yielded otter DNA, 77 (41.2%) were successfully typed, and 23 different genotypes were identified. A nonlinear regression between the number of typed spraints and the cumulative number of identified genotypes was repeated after randomization of the sample until it gave an estimated otter population of 34â37 animals (0.18â0.20 otters/km of watercourse). The applied method represents a valuable conservation tool, combining the advantages of an indirect survey with the accuracy of an exhaustive census.
Abstract: From June 2000 to December 2003 a low-density badger (Meles meles) population
was studied by radiotelemetry in an area of agricultural lowland in northern Italy. Four badgers, one male (M1) and three females (F1, F2, F3) were caught but only three of these were radio-tracked for 8-12 months because the transmitter attached to F3 failed. Tracked animals showed considerable home range overlap, with an overall mean size of 3.83 km2 (M1 = 3.22 km2, F1 = 2.39 km2, F2 = 5.87 km2, Minimum Convex Polygon of 100% of the locations). In the study area 10 setts (mean number of entrances = 2.1) were detected. Each radio-collared badger used 2-3 setts, occupying one sett from 1 to 8 months (mean = 3.7 months, SD = 3.06) before moving to another one. All badgers shared, although in different periods, one main sett located in the inner part of their ranges. Considering this evidence and additional data about badger translocation from neighbouring areas, the social structure badgers in northern Italy is discussed
Abstract: Between 2001 and 2004, with the aim of restoring the natural biodiversity of a protected area, the Eurasian badger (Meles meles) was reintroduced into the Montevecchia and Curone Valley Regional Park (northern Italy), where it had been
extirpated by human persecution. The project was combined with the reduction of badger damage on railway tracks allowing at least a pair of badgers per year and to move animals whose translocation would have been anyhow imposed by
precautionary measures. Four badger family groups (a total of 12 animals) were trapped and moved to an acclimatisation enclosure located in the middle of the release area. Post-release monitoring was carried out by both radio-tracking and
indirect methods. The average group range size (1.58 km2) was similar to reports from favourable districts in Britain, supporting the contention that badgers can thrive in this area. Radio-tracked badgers selected woods, while urban areas and
cultivated field were avoided. Although results indicate that the badger has actually established in the Park, with badger field signs currently spread on 40% of the protected area, more monitoring is needed to determine whether it is at sustainable
levels or if more translocation should be considered.
Abstract: The diet and feeding relationships of two cyprinids, the Italian orange-fin roach Rutilus rubilio and the chub Leuciscus cephalus, were studied in southern Italy by the analysis of 189 gut contents. Fish species were sampled in conditions of
sympatry/hybridisation in the River Sinni, and allopatry in the River Mercure-Lao (roach) and in the River Raganello (chub). The diet of both fish species included both plant material and invertebrates. The broad spectrum of prey eaten
showed that both fish species looked for invertebrates along the whole water column and particularly on the surface. For the River Sinni a high dietary overlap was found. The high contribution of plant material in the overall diet of roach in the
presence of other cyprinids species, compared with the almost equal importance of plant material and animal food in allopatry, suggested that competition could be the cause of roach dietary shift towards suboptimal food sources. For the river Raganello, the high proportion of vegetation in the diet of chub, compared to the River Sinni, was explained as a consequence of habitat degradation caused by anthropogenic activities. Our results confirmed the generalist and opportunistic foraging behaviour of both fish species.
Abstract: Between 2001 and 2004, 229 foxes, 36 stone martens and 48 badgers from the western Italian Alps were examined for sarcoptic mange and for gastrointestinal helminths to investigate their prevalence and geographical distribution and to point out the existence of potential interactions among them. Sarcoptic mange was observed in 25.3±2.8% SE of foxes and in 5.6±3.8% SE of stone martens, while no badger was found infected. Helminths belonged to Cestoidea Cyclophillidea (3.0±1.1% SE), Nematoda Trichurida (Capillaria aerophila and Trichuris vulpis: 6.5±1.6% SE; Trichinella britovi: 3.0±1.1% SE), Ascaridida (12.2±2.2% SE) and Strongylida (6.9±1.7% SE). Sarcoptic mange infection and the presence of helminths proved to be associated, with mangy foxes showing significantly higher prevalence of both cestode and nematode (particularly Ascaridida) worms. Moreover, considering three clusters of parasites (S. scabiei, nematodes and cestodes), more foxes than expected hosted simultaneously 2 and 3 taxa. These evidences suggest the existence of some kind of interaction, whose modalities and implications are discussed in this paper
Abstract: Food habits of the red fox (Vulpes vulpes) were studied in the Aosta Valley region (NW Italian Alps) and were related to the prevalence of Trichinella infection in the red fox itself and in two Mustelid species (the stone marten (Martes foina) and the badger (Meles meles)). The search of Trichinella by the automatic digestion of muscles samples led us to determine a prevalence of 3.5+/-1.2% in red foxes, 7.9+/-4.3% in stone martens and 1.9+/-1.8% in badgers, with no significant differences among the species. All larvae were identified as Trichinella britovi. The fox diet was assessed through the analysis of both faeces (n=180) and the stomach contents of road-killed animals (n=109). Our results confirmed the opportunistic feeding behaviour of the red fox, which is able to use various trophic resources, both of animal and vegetal origin: e.g. wild and cultivated fruits (F%=47.1; V%=67.3), rodents (F%=22.8; V%=64.8) and carrion (F%=15.6; V%=78.6) formed the bulk of the fox's diet. The frequency of occurrence of potential events of cannibalism was 1.0%, even if the complete absence of undigested remains, other than hairs, suggested the possibility of confusing cannibalism with coat-cleaning. We suggest that intra-specific necrophagy could not represent the unique way of transmission of the nematode in natural conditions.
