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We applied molecular analysis methods to faecal samples to determine both the overall level of occupancy for pine marten (Martes martes) and current stone marten (Martes foina) distribution in the western Po plain. Surveys were carried out in a 10 × 10-km grid, applying a hybrid sampling design. The specific identification of faecal samples was accomplished either by a polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) method or by amplifying and sequencing a 330-bp mtDNA fragment of the control region (D-loop). Identification success was 93.7 % by the PCR-RFLP and 71.7 % by DNA sequencing. Overall, we collected 47 pine marten records and 24 stone marten records. Thirty-six squares (81.8 %) were found to be positive for at least one marten species, the distribution range of the two species scarcely overlapping. The pine marten was shown to be widespread in lowland areas on the north bank of the River Po, which is probably acting as a barrier to its expansion. In this area, stone marten records were few, while it is was widespread on the south bank of the river. Pine marten expansion may have forced the stone marten to restrict itself to less suitable agricultural and urban areas. Nonetheless, we cannot exclude that stone marten range and/or numbers may being declining as a consequence of pine marten expansion. Six pine marten samples belonged to the Central-Northern European (CNE) phylogroup. The relatively high percentage of CNE martens is consistent with the hypothesis of an ongoing expansion of Alpine and trans-Alpine pine marten populations.

Italy is amongst the European countries for which data on badger Meles meles numbers and variation in population size are still too few to assess its conservation status. With the aim of estimating badger density in northern Italy, between February 2013 and March 2014, we extensively surveyed an isolated hilly area for badger setts and assessed group size by monitoring a sample of setts by two sessions of camera-trapping. The size and shape of each home range were assessed from main sett coordinates using the Dirichlet tessellation method. Then, assuming that badger home ranges tend to be delimited by hard boundaries or geographical features, the polygon shapes were successively modified by hand to draw more realistic home ranges. The overall trapping effort was 754 camera trap-days. The number of badger individuals sharing the same sett/entrances was recorded, distinguishing individuals based on the time and hole of emergence and, possibly, tail patterns. Groups consisted of two to four adult individuals, averaging 2.75 badgers/group. Camera-trapping proved to be a cost-effective and time-saving method. Depending on the method used to draw home ranges, in the study area, sett density was 0.34–0.51 sett/km2, whilst badger density was 0.93–1.4 adult individuals/km2. Both sett and badger densities were rather high with respect to most available data for continental Europe. As badger mean group size seems to be rather constant throughout both hilly and plain areas of the River Po basin, sett density may be used as an accurate estimator of badger density throughout this wide area.

In countries with emerging and developing economies the need to promote development and the lack of information on the status of the Near Threatened Eurasian otter Lutra lutra have given rise for concern about the conservation status of the species. In Albania information about the distribution of this otter dates from 1985. In 2013 we resurveyed 31 sites previously surveyed in 1985, and a further 42 sites throughout the country. At each site nine habitat variables of potential importance to otters were recorded and analysed. Overall the distribution pattern in 2013 did not differ from that recorded in 1985, although a reduction in marking intensity suggested a possible decline in otter numbers. Distribution of the otter has been influenced by land use and human density, suggesting man-induced habitat changes since the fall of communism may have affected the quality and fragmentation of otter habitats.

The location of pine marten records in northern Italy suggests that main rivers may play the role of natural corridors favouring this species’ colonisation of cultivated lowlands. We assessed the distribution and habitat use by the pine marten on a 35 km long stretch of the River Ticino. Surveys were carried out between October 2011 and June 2012 along linear transects in a 2 × 2 km grid. Using the variation in marking intensity as an indicator of habitat use, habitat selection was assessed at two landscape levels—at transect-scale by the χ 2 test with Bonferroni’s confidence intervals for the proportion of use, and at grid-scale by multiple linear regression. By a polymerase chain reaction–restriction fragment length polymorphism method, 91 faecal samples were assigned to the pine marten. Faeces were mainly located in wooded areas, while fields were avoided. At the grid-scale of analysis, marking intensity was positively related to the mean area of wooded patches and negatively to their mean perimeter-area ratio. This suggests that pine marten relative abundance may partially depend on the degree of fragmentation and structure of residual woods. The survey protocol allowed to assess the probability of detection. Occupancy models outlined that heterogeneity in detection probability may arise as a result of variation in marking intensity, i.e. the number of marking individuals. Our results suggest that the availability of both woodland corridors and wood patches are major factors shaping pine marten distribution in intensively cultivated plains and that non-invasive genetic surveys are a cost-effective method for future studies at a broader scale.

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.

In the two last decades, the pine marten Martes martes has expanded in the River Po plain, causing the displacement of the stone marten M. foina from residual wooded areas. As a high degree of food niche overlap can favour exploitative competition and information about stone marten diet in Northern Italy was scarce, we analysed a sample of 181 stone marten faeces collected, prior to pine marten expansion (1997–1998), in the hay-lofts of farms located in the central plain of the River Po. Results were expressed in terms of both frequency of occurrence and mean percent volume, while seasonal variation was assessed by Compositional Analysis. The availability of small mammals was assessed by the analysis of 116 barn- and tawny owl pellets. The bulk of stone marten diet was made up of four main items in equal parts: fruit, birds, lagomorphs and small rodents. Seasonal variation occurred for fruits, which were eaten more in the ripening season, and birds, which were less preyed upon in spring/summer. I...

Summary 1. Biological invasions are considered a major threat to biodiversity. Most research has focused on the distribution, biology and impacts of non-native species on native fauna and flora. However, few studies have explored their role as prey for native predators of conservation concern. 2. To assess the incidence and intensity of predation by the Eurasian otter Lutra lutra on established non-native fish species, data were collated from the published literature. To be selected, studies had to cover at least 1 year, analyse more than 100 spraints and report the study period and percentage relative frequency (%RF) of all prey fish species. 3. To permit reliable, time-related comparisons with %RF of non-native fishes in otter diet, we also reviewed available information about both the distribution of non-native fishes and history of their introductions to European countries, revealing a decrease with longitude in the number of naturalised non-native fishes taken (ranging between 5 and 34) and their percentage in each fish assemblage. 4. Our selective criteria were met by 30 dietary studies from 44 study areas in 15 European countries during 1970–2010. The extent to which otters rely on non-native fishes was almost negligible (mean %RF = 4.8), with the number of non-native fishes preyed upon by otters decreasing with both latitude and longitude. 5. The %RF of non-native fish in the diet increased slightly with time, with otters preying significantly more on non-native fish in study areas where alterations of the fish assemblage had been highlighted in the reference papers. No relationship was found between otter diet breadth and the occurrence of non-native fishes in their diet. 6. The current role of non-native species in otter diet suggests that effective otter conservation management plans should focus on the maintenance and/or enhancement of native fish assemblages.

In marginal habitats, populations should reach lower densities, as a consequence of both lower overall abundance and increasing home range size. To test if recently colonized riparian woods crossing intensively cultivated lowlands of NW Italy represent marginal habitats for the forest-specialist pine marten Martes martes, we assessed its population density by a recently developed, camera-trap-based non-invasive method, the Random Encounter Model (REM). As the central assumption of the REM is that animals move randomly with respect to cameras, we suspected that this method may be unsuitable for species with a strong tendency to use linear elements of the territory as usual paths and select habitats, such as woodland, which are likely to be under-represented in fragmented landscapes. To test for the efficacy of the REM, we also applied a faecal DNA-based genetic census to obtain an independent estimate of the minimum number of individuals occurring in the study area. Camera-trapping used 10 camera-traps, deployed for 10 days within a 2 km2 large unit, for a total of 6 units and 12 km2. Pine marten density was estimated at 0.48 (0.36–0.60) ind/km2. All the faecal samples identified by a mDNA-based PCR-RFLP method as pine marten were genotyped at 15 microsatellite loci using a multiplex protocol. We identified 15 different individuals, corresponding to a density ranging between 0.8 and 2.0 ind/km2. Using the most conservative genetic estimate, the REM underestimated population density of about 60% proving to be unreliable for estimating pine marten population size. We suggest that this may be the case for elusive species for which the assessment of average daily movements cannot be achieved without the use of invasive methods.

The stone marten (Martes foina) and the pine marten (M. martes) are closely related mammalian carnivores potentially subject to exploitative competition. The recent expansion of the pine marten into the intensively cultivated plain of the River Po (NW Italy), where previously only stone marten occurred, offered an interesting opportunity to analyse their relationships. We studied the distribution and diet of Martes species and trophic niche overlap between martens and red foxes (Vulpes vulpes) in two study areas, each with two pseudoreplicates, by analysing genotyped faeces. Our results seem to confirm the displacement of the stone marten from one study area, the pine marten being the only Martes species occurring where previously the stone marten had been reported. We found a large food niche overlap between red fox and both stone and pine martens, but with evidence of size-related differences in the consumption of some food items. We hypothesised that, due to the poor prey-base of the environment, highly altered by intensive crop cultivation, intense interspecific competition originally occurred between the red fox and stone marten. The heightening of interspecific competition caused by the entry of the pine marten in the predator guild may have caused the displacement of the stone marten, at least temporarily. The mechanism of such displacement needs to be clarified through further surveys in areas where the three species occur sympatrically.

In the second half of the twentieth century, European otter populations crashed in large areas of the Italian peninsula. As a consequence, at the end of the century the Italian otter population consisted of five isolated nuclei, the extinction of which had been foretold to occur within a few decades.

In the context of intraspecific competition, the distribution of key resources within a territory could influence the spatial patterns of scent deposition by territory owners, in order to maximise the defensibility of resources and reduce the costs of their defence. We investigated the pattern of spraint deposition by the Eurasian otter (Lutra lutra) in Mediterranean rivers of southern Italy, testing the hypothesis that spraints are concentrated around deep pools bordered by riparian vegetation because these represent important patchy sources of food. Otters strongly selected pools throughout the year, marking the largest ones which probably supported the highest fish biomass. Sprainting sites at pools were also marked more consistently than sites elsewhere on watercourses. A positive correlation between the percentage of spraints next to pools (pool markings) and overall volume of the main prey in otter diet confirmed the importance of pools as sources of prey. These results are consistent with the idea ...

We assessed the diet of pine marten (Martes martes) expanding in the heavily human-altered agricultural plain of the River Po, northern Italy. Between February 2008 and November 2009, surveys were carried out twice a week during seasonal sampling sessions of three to four consecutive weeks. To distinguish the faecal samples from those of sympatric carnivores, a polymerase chain reaction-restriction fragment length polymorphism method was applied. The availability of small mammals was assessed by the analysis of 59 barn owl (Tyto alba) pellets. A total of 109 pine marten faeces were analysed. Its diet consisted of fruit, rodents, lagomorphs and birds. Seasonal variation occurred for fruit, which prevailed in summer, and rodents, which were more preyed upon in autumn. In winter, the diet of the pine marten was almost totally based on vertebrates, and lagomorphs were the main source of protein in summer. Use of small mammals differed significantly from their availability, voles, particularly bank vole Myodes glareolus, being preferred to mice (Apodemus sp.) and rats (Rattus sp.). Medium-size mammals formed about 18% of pine marten diet, a value generally reported for high-latitude habitats. In agricultural areas, the pine marten proved to be an opportunistic predator, able to face the reduced availability of small mammals by preying upon medium-size prey and fruit.

The marking behaviour of the European badger (Meles meles L., 1758) in a low-density population of NW Italy was investigated by examining the distribution and pattern of use of latrines in relation to space-use by a badger social group, as assessed by radiotracking. Latrines were mostly placed close to linear features and marked the core area of the group. The winter-spring peak in latrine use suggested that marking behaviour was correlated to reproductive cycle and involved in sexual advertisement.

Although originally evolved as predators, several species of mammalian carnivores exhibit a great trophic diversity, ranging from hypercarnivory to a high consumption of vegetable food. Habitat characteristics influence food availability and consequently could affect the nutritional composition of the diet of generalist species. By reviewing the available literature, we tested the hypothesis that intraspecific differences in the food habits of badgers (Meles meles) living in different habitats across Europe could affect the percentage of macronutrients (i.e., protein, lipids, and carbohydrates) in their diet. Notwithstanding the different composition of the diet, the percentage of protein and lipids fed by badgers did not vary among temperate forest-pasture mosaics, Mediterranean woodlands, or scrublands and arable lands, suggesting a certain form of regulation of the diet balance. The percentage of carbohydrates was similar in the first two habitats, while it was fivefold higher in arable lands, where cereals were the main food of badgers and were consumed throughout the year. Earthworm consumption by badgers was positively related to the latitude, while the lack of any latitudinal or altitudinal pattern in protein consumption reflected the absence of a gradient in carnivory. A slight inverse latitudinal gradient in lipids consumption probably depended on the use, in southern Europe, of vegetal foods rich in lipids. We hypothesize that in agricultural landscapes dominated by crop cultivations, the decline of animal prey (i.e., earthworms, insects, and vertebrates) due to habitat loss forced badgers to increase the percentage of protein in their diet by over-eating cereals, with the consequence of a disproportionate increase in carbohydrate consumption.

False negative detections may bias the surveys for rare species and reduce the reliability of models based on the proportion of occupied patches. We assessed the detectability of the Eurasian otter Lutra lutra through the standard survey method by analysing the detection history of 28 sampling stretches surveyed monthly between March 2001 and January 2003. Each survey negative for otter spraints was considered as a false negative if the otter had been recorded in the previous and/or following month (respectively, cFN and FN). Otter marking intensity (MI) (MI=N° of spraints per kilometre) was calculated and assumed to represent an index of its relative abundance. Spraints were found in 81.7% of all surveys. Yearly MI ranged from 1.02 to 101.4 spraints per kilometre. In 2002, mean MI was significantly lower than in the previous year, while no clear seasonal trend could be outlined. The minimum number of surveys required to establish the occurrence of the otter, as estimated by a probability model, was 2.6 and was inversely related to MI. For a sub-sample of 18 sampling stretches, the relation between the frequency of both cFN and FN and five variables of potential interest for otters was tested by means of stepwise linear multiple regressions, yielding two highly significant models, which both included only MI as the explanatory variable. The frequency of both FN and cFN was correlated to MI and the resulting equations used to assess the percentage of surveys positive for otters in both years. After the correction for non-detections, otter site occupancy did not vary between the 2 years, except for one river when applying the more conservative estimate of false negatives (cFN). Multiple visits and the assessing of MI should become standard components of otter surveys. This approach has broad applicability and may be applied to assess the large-scale distribution of other rare or elusive mammalian carnivores.

Habitat segregation is considered to favour the coexistence of sympatric pine martens Martes martes and stone martens M. foina, the latter being displaced to agricultural and urbanised areas. Subsequent to the report of pine martens in cultivated areas of the western River Po plain (NW Italy), we reviewed all available information on the presence of this species in plain areas of northern Italy and, for two study areas, applied a non-invasive PCR-RFLP method for the identification of Martes species from faecal mtDNA. A total of 24 pine marten records were collected, grouped in the western part of the River Po plain. The number of records showed an exponential increase from 1988 to 2007, the percentage of woods in a 10 km2 wide circular plot surrounding the location of records being inversely correlated to its distance from the 300 m a.s.l. contour line. In the two study areas, 36 out of 119 “marten-like” faeces were assigned to the pine marten, whilst none belonged to the stone marten. In the best monitored area, the pine marten was present almost constantly. Our results suggest that the pine marten is expanding its range to include cultivated areas which were previously considered a prerogative of the more synanthropic stone marten.

In 2001 and 2002 we studied Eurasian otter (Lutra lutra) fish selection in southern Italy by comparing otter diet (805 analysed spraints) with fish availability, estimated by electrofishing. The surveyed river was dominated by cyprinids, particularly by chub (Leuciscus cephalus), roach (Rutilus rubilio) and bleak (Alburnus sp.). Roach and chub were the most common prey recorded in spraints. Otters ate mainly small prey (total length < 90 mm). Chub were widely consumed according to abundance, whilst roach and bleak consumption was not proportionate to their availability. Otters selected roach both in 2001 and 2002 and responded to a decrease in roach availability (–27.3%) by increasing their frequency of consumption rather than switching to an alternative prey. Despite their high abundance, bleak seemed to be markedly avoided by otters. We hypothesized that differences in microhabitat selection may influence the susceptibility of cyprinids to otter predation. The possible effects on fish community...

Indirect methods such as faecal counts have been widely used for assessing the abundance and habitat preferences of many mammal species, although their reliability has been long debated. We tested the validity of this method for the Eurasian badger Meles meles in a low-density population in northern Italy by comparing results obtained from radio-tracking and latrine distribution. The pattern of habitat use extrapolated from each method was strikingly similar, with badgers selecting for patches of woodland and avoiding agricultural and urban areas. Latrines were mainly sited in the centre of activity of all individuals along man-made linear features. Although our data need to be validated over a wider range of social groups, evidence suggests that latrines might be used to broadly infer habitat preferences of badgers at the landscape level in low-density areas.

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.

Diet composition of otters (Lutra lutra) was investigated in 2001 by spraints analysis (N=1323) on five rivers of southern Italy, with the aim of assessing the influence of fish availability, elevation and discharge on the consumption of food resources alternative to fish. Data were expressed as per cent frequency of occurrence (%FO) and per cent volume (%V). The study confirmed the great feeding adaptability of the otter that, in rivers partially interconnected and flowing on a small area, showed a strong fish 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 five rivers was significantly correlated with fish biomass and with mean summer discharge, while it was inversely correlated with the mean altitude of the five rivers. The lack of a clear seasonality in the consumption of food sources alternative to fish together with the correlation between fish use and fish biomass for each river indicated fish availability as the main factor affecting otter relying to non-fish preys. Otter diet seemed influenced by the characteristics of river habitats (altitude, discharge and consequently fish 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.

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 (n = 133 faecal samples), the badger (n = 177), the pine and the stone marten (Martes sp., n = 382). 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 pre...

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.

The diet composition of otters in the upper catchment of the River Agri (southern Italy) was investigated by spraint analysis (N = 555) between May 2001 and January 2003. Once a season, spraints were collected along four riverine stretches, two with swift-waters and two with slow-waters. Overall, fish represented the dominant food (percent mean volume, Vm% = 57.30), followed by amphibians (Vm% = 18.90) and crayfish (Vm% = 15.60). The food composition of otters feeding along swift-water sections differed significantly from that recorded along slow-water sections. The trophic niche was larger for slow-water sections, because of the presence of more fish species. In both sampled habitats (swift- and slow-waters) the importance of fish decreased in winter when flooding increasing water speeds and turbidity and thus reduced the hunting efficiency of the otters. Hibernating amphibians represented a primary alternative resource. As expected, insects and reptiles were eaten more frequently in summer, while birds ...

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 34‐37 animals (0.18‐0.20 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.

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 badge...

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.

From March 2001 to December 2002, 32 stretches (sampling stations, mean length 673 m) distributed on 17 watercourses of the Pollino National Park (southern Italy) and the surrounding area were searched monthly for otter Lutra lutra signs, mainly spraints. All the watercourses were positive for otter with a mean percentage of 82.2%, indicating a stable presence of otters, mainly on Sinni and Mercure-Lao catchments (central-northern part of the park). Mean sprainting activity was 12.8 sprainting sites/km and 31.7 spraints/km, and showed a seasonal variation only in 2001 with two peaks, in May-June and in October. Sprainting activity was positively correlated with the percentage of positive stretches on watercourses, confirming that spraint density can represent an indicator of the population size of otters. A preliminary evaluation of the relationship between fish availability and otter marking intensity was performed along 39 km of the River Sinni on one day. A positive correlation was found between sprain...

Badger Meles meles sett distribution was analyzed in a protected area (425 ha), NE Italian Alps, extending from 1000 to 1600 m a.s.l. Thirty setts with a mean number of 1.8 entrances were recorded, all localized below boulders. In order to examine the factors affecting sett choice, 12 variables were considered including physical and morphological characteristics, human disturbance, vegetation cover and tree/shrub species around the sites. Variables for 30 sett sites were compared with those for 30 randomly selected ones. Sett sites were localized on more sloping soils and under larger boulders, with a narrower slope angle than random sites. In addition, they had a thicker total vegetation cover and were more distant from disturbance sources. Around the sett, broadleaved trees were more common than around the random sites. Using a logistic regression model, the factors affecting sett site selection were primarily the physical characteristics of boulders (slope angle with the soil and size) and, in...

Twelve heronries were investigated in the Po plain (northwestern Italy) from 1974 to 1984. A total of 219 blood films was obtained from chicks and young of the night heron Nycticorax nycticorax and the little egret Egretta garzetta, 24.6% of which harboured Leucocytozoon parasites. Infection prevalence varied between heronries, mainly due to variation in simulid abundance. The abundance of vectors was affected by the agricultural practices for rice cultivation: irrigation canals and ditches were periodically drained and cleaned out with the consequent destruction of the aquatic vegetation in which simulid larvae and pupae settle. Discrimination of heron colonies (number of cases) where infection was detected from those where infection was not detected was mainly by simulid abundance, and secondly by colony population size. From 1974–1979 to 1980–1984 the increase in infection prevalence seems to be associated either with the increase in the number of breeding herons or the decrease in the number ...

Eurasian otter populations strongly declined and partially disappeared due to global and local causes (habitat destruction, water pollution, human persecution) in parts of their continental range. Conservation strategies, based on reintroduction projects or restoration of dispersal corridors, should rely on sound knowledge of the historical or recent consequences of population genetic structuring. Here we present the results of a survey performed on 616 samples, collected from 19 European countries, geno- typed at the mtDNA control-region and 11 autosomal microsatellites. The mtDNA variability was low (nucleo- tide diversity = 0.0014; average number of pairwise dif- ferences = 2.25), suggesting that extant otter mtDNA lineages originated recently. A star-shaped mtDNA net- work did not allow outlining any phylogeographic infer- ence. Microsatellites were only moderately variable (Ho = 0.50; He = 0.58, on average across populations), the average allele number was low (observed Ao = 4.9, range 2.5–6.8; effective Ae = 2.8; range 1.6–3.7), sug- gesting small historical effective population sizeotters likely originated from the expansion of a single refugial population. Bayesian clustering and landscape genetic analyses however indicate that local populations are genetically differentiated, perhaps as consequence of post-glacial demographic fluctuations and recent isolation. These results delineate a framework that should be used for implementing conservation programs in Europe, particu- larly if they are based on the reintroduction of wild or captive-reproduced otters.

Food availability has been suggested to be the main factor shaping the altitudinal limits of species distributions. We analyzed the badger (Meles meles) diet in the western Italian Alps and, particularly, at the altitudinal limit of its range, with the main aim of highlighting any reduction in earthworm availability with altitude which could act as a limiting factor for badgers. Earthworms were by far the main food resource of badgers, followed by fruit. The two-month importance of these two items in badger diet was inversely correlated. Earthworm consumption was negatively correlated with air temperature. The seasonal pattern of earthworm use by badgers seemed to be influenced by the reproduction and estivation times of some epigeic species, rather than by climatic conditions per se. The eating of fruit by badgers was at least in part independent from the availability of earthworms. The badgers' efficacy in preying upon earthworms also in adverse conditions and their reliance on a wide variety of food resources suggest that worm availability might play a minor role in shaping the altitudinal limit of the species on the Alps.

Management of recolonising species needs precise knowledge concerning those environmental parameters that can influence 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 confined to southern Italy. At the southern boundaries of the Italian otter range, the influence 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 efficacy. 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. Thus we argue 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. Our findings have implications for landscape restoration projects, suggesting that provision of suitable habitat alone may not be sufficient to effect recolonisation by some species.

The food of the otter Lutra lutra (Linnaeus, 1758) was studied on the Fiora River (Central Italy) by the analysis of148 spraints collected at monthly intervals from August to October 1982 and from January to April 1983.

During a survey in Albania we found signs of otters at 17 (54·8%) of the 31 stations investigated. Otters were widespread in much of the country, and healthy populations were localised in rivers and marshes in the north-west and in the south. Average sprainting activity was 1·7 positive sites per 200 m and 3–6 spraints per 200 m. Frogs, probably Rana ridibunda , as well as fish, appeared to be important prey for otters. In the coastal plains, several rivers were grossly polluted and the growing agricultural and industrial development may endanger the survival of otters.