A comparative analysis of craniological variability of Eurasian (sable and pine marten) and North American (American marten) species of the <Emphasis Type="Italic">Martes</Emphasis> genus

This paper studies the craniological variability of closely related species—the pine marten Martes martes, the American marten M. americana, and the sable M. zibellina. The study included the data on 22 nonmetric characters of skulls in 2344 individuals. The studied Martes species were revealed to have an evident species-specific manifestation of the investigated craniological characters. Sables stand apart most of all in the interspecific comparison of populations. The degree of epigenetic variability is somewhat higher in the sable than in the pine marten. The American marten significantly differs from Eurasian species in the manifestation of the nonmetric skull characters, which is noted when analyzing even a small number of samples.     

Serologic survey for selected viral pathogens in free-ranging endangered European mink (Mustela lutreola) and other mustelids from south-western France

To investigate the possible role of selected pathogens in the decline of endangered European mink (Mustela lutreola) populations and the potential for these pathogens to affect mink survival, a serologic survey was conducted using serum samples collected from March 1996 to March 2003 in eight departments of south-western France. In total, 481 free-ranging individuals of five mustelid species (including the European mink) were tested. Sympatric mustelids can serve as sentinels to determine the presence of antibodies to viruses in the study area that could potentially infect mink. Antibodies to Canine distemper virus (CDV) were detected in all species; 9% of 127 European mink, 20% of 210 polecats (Mustela putorius), 5% of 112 American mink (Mustela vison), 33% of 21 stone marten (Martes foina) and 5% of 20 pine marten (Martes martes). Antibody prevalence was significantly higher in stone marten and polecats, possibly because their ranges overlap more closely with that of domestic species than that of the other species tested. Antibodies to Canine adenovirus were detected in all species but the pine marten; antibody prevalence estimates ranging from 2% to 10%. Antibodies to canine parainfluenza virus were detected in 1% of European mink, 1% of American mink and 5% of tested polecats but were not detected in Martes species. Antibodies to Rabies virus (RV) were detected in three animals, possibly because of interspecies transmission of bat lyssaviruses as the sampling area is considered to be free of RV, or to a lack of test specificity, as antibody titers were low. The high antibody prevalence to potentially lethal CDV suggests that this pathogen could have significant effects on the free-ranging populations and has implications for the conservation efforts for the endangered European mink.     

Diet of free-ranging American mink and European polecat in Denmark

Stomach and intestine contents of 211 American minkMustela vison Schreber, 1777 from two areas (Thy and Bornholm) in Denmark and stomach contents of 47 polecatsM. putorius Linnaeus, 1758 from Thy were analysed. Sympatric mink (from Thy) preyed mostly on mammals (55% occurrence), followed by amphibians (36%), birds (33%) and fish (30%), whereas polecat preyed mostly on amphibians (87%) and mammals (34%), and only occasionally on birds (9%) and fish (6%). Allopatric mink (from Bornholm) preyed mostly on birds (50%), followed by mammals (42%), fish (25%) and amphibians (4%). With the possible exception of some amphibians, no endangered species were found in their diet. No differences were found in food composition between wild and escaped farm mink. The concern that mink in general might have a detrimental effect on its prey species and other mustelids in terms of food competition in Denmark may be unjustified. It cannot be ruled out, however, that mink may locally have a seriously negative effect on some specific prey species, and clearly, more data is needed on eg prey abundance and spring and summer mink diet, to make stronger conclusions.     

Intrapopulation Polymorphism of the Pine Marten (<Emphasis Type="Italic">Martes martes</Emphasis>, Carnivora,Mustelidae) from Tver Oblast

The intrapopulation polymorphism of the pine marten (Martes martes L. 1758) was assessed on the basis of studying five samplings of skulls, three of which were collected on the same territory at different times. The geographical distance between the three sampling areas varied from 60 to 240 km. Study of the material using the phenetic (250 skulls), morphometric (151 skulls), and molecular genetic (21 skin samples) approaches allowed us to characterize the pine marten as a species with a low level of polymorphism. The genetic diversity (π = 0.0069 ± 0.0041 and H = 0.90 ± 0.039) is determined by ancient demographic processes that took place in the Pleistocene and Holocene and are related to the ice-age history of this species, its expansion, and the formation of the population on the territory under study. Low levels of phenetic (μ = 1.48 ± 0.056, h = 0.14 ± 0.033) and morphological (CV = 3.37 ± 0.41) diversity as well as a low level of sexual dimorphism (Isd = 9.4) indicate that the pine marten occupies a specific and relatively narrow ecological niche and is involved in weak competition with smaller mustelid species.     

Habitat requirements of Eurasian pine marten <Emphasis Type="Italic">Martes martes</Emphasis> in a Mediterranean environment

Evaluating presence and habitat requirements of small carnivores is essential for their conservation. The Eurasian pine marten Martes martes, often described as a habitat specialist associated primarily with forest habitats, has been recently found to live even in patchily wooded country and in shrublands. We evaluated the environmental factors that determine the distribution of the pine marten in a Mediterranean landscape on the island of Sardinia (central Italy). Camera trapping sessions and scat surveys were carried out to assess the presence of the species, then a potential distribution model was developed using ecological niche factor analysis (ENFA), which requires only presence data. The pine marten selected highest altitudes, shrublands, rocky areas, and woodlands, and avoided urban areas and arable lands. Our results indicate that pine marten distribution in our study area is constrained by these variables. The ENFA analysis provided important clues about the distribution range of M. martes and its preferential environmental conditions, updating knowledge of its ecological requirements in Italy.     

Fruit consumption by carnivores in Mediterranean Europe

• 1 We reviewed patterns of fruit consumption amongst 10 species of mesocarnivores: red fox Vulpes vulpes, weasel Mustela nivalis, stoat Mustela erminea, polecat Mustela putorius, stone marten Martes foina, pine marten Martes martes, Eurasian badger Meles meles, common genet Genetta genetta, Egyptian mongoose Herpestes ichneumon and wildcat Felis silvestris in Mediterranean Europe.
• 2 The 65 reviewed studies recorded 79 different fruits eaten by carnivores, 58 of which were identified to species. Most records (63%) were of fleshy fruits with high pulp content. The frequency of occurrence of fruit items varied widely amongst species and regions. Four of the carnivore species (red fox, stone marten, badger and common genet) included more than 30 fruit species in their diet.
• 3 A longitudinal pattern was detected in the consumption of fruit in the Mediterranean region, with the frequency of occurrence of fruit consumption increasing towards the east.

     

The NATURA 2000 database as a tool in the analysis of habitat selection at large scales: factors affecting the occurrence of pine and stone martens in Southern Europe

Most studies on habitat selection among animals are conducted at local scales, whereas reliable determination of species requirements at larger spatial scales can be problematic. We used data available for NATURA 2000 sites to determine the habitat requirements of two relatively widespread and common species—pine marten Martes martes and stone marten Martes foina—in Southern Europe. Using presence-absence data, we applied statistical models at two spatial scales. At the local scale (within the dispersal distances of the species), sites occupied by martens were compared with unoccupied sites using buffers of different sizes, whereas at the regional scale, unoccupied sites were selected randomly. To adjust for spatial autocorrelation of data, penalised quasi-likelihood approximations were used. Both species of martens demonstrated preferences for areas with higher proportions of forest cover and steeper terrain. At the local, but not at the regional, scale, pine martens occurred at lower elevations, whilst stone martens occurred at higher elevations. We found that climatic variables (mean temperature, precipitation) had no significant effect on the presence of the martens. The results of our analyses generally confirmed findings of previous studies on habitat selection of both marten species in Southern Europe. This demonstrates the utility of data collected for NATURA 2000 sites for use in various analyses such as conservation planning and evaluating the impact of climate change on the distribution of animal species.     

Genetic diversity of MHC class II <Emphasis Type="Italic">DRB</Emphasis> alleles in the continental and Japanese populations of the sable <Emphasis Type="Italic">Martes zibellina</Emphasis> (Mustelidae,Carnivora, Mammalia)

The sable (Martes zibellina) is a medium-sized mustelid inhabiting forest environments in Siberia, northern China, the Korean Peninsula, and Hokkaido Island, Japan. To further understand the molecular evolution of the major histocompatibility complex (MHC), we sequenced part of exon 2 in MHC class II DRB genes, including codons encoding the antigen binding site, from 33 individuals from continental Eurasia and Japan. We identified 16 MHC class II DRB alleles (Mazi-DRBs), some of which were geographically restricted and others broadly distributed, and eight putative pseudogenes. A single-breakpoint recombination analysis detected a recombination site in the middle of exon 2. A mixed effects model of evolution analysis identified five amino acid sites presumably under positive selection. These sites were all located in the region 3′ to the recombination site, suggesting that positive selection and recombination could be committed to the diversity of the M. zibellina DRB gene. In a Bayesian phylogenetic tree, all Mazi-DRBs and the presumed pseudogenes grouped within a Mustelidae clade. The Mazi-DRBs showed trans-species polymorphism, with some alleles most closely related to alleles from other mustelid species. This result suggests that the sable DRBs have evolved under long-lasting balancing selection.     

Comparative study of catalytic properties of mink and rat liver monoamine oxidase

Comparative substrate-inhibitor analysis of catalytic properties of mitochondrial monoamine oxidase (MAO) of liver of the American mink Mustela vison Schreber and of liver of Wistar rat has been performed. It has been found that MAO of mink, like MAO of rat, has properties of classic mammalian MAO: it deaminates tyramine, tryptamine, serotonin, benzylamine, β-phenylethylamine and does not deaminate histamine as well as does not have sensitivity to semicarbazide. Study of kinetics of the monoamine oxidase deamination revealed both qualitative and quantitative differences between these enzymes. Specificity of action on MAO-A form of four irreversible inhibitors—acridine derivatives—has been shown; this specificity was several times higher for the mink liver MAO than for the rat liver MAO. It is suggested that the liver MAO of both species of the studied animals has several isoenzyme forms or several centers of the substrate binding.     

Antibodies to Aleutian mink disease parvovirus in free-ranging European mink (Mustela lutreola) and other small carnivores from southwestern France

Owing to the rapid decline of the European mink (Mustela lutreola) in France, a national conservation action plan has been initiated, in which scientific research to improve understanding of the causes of the decline is one of the primary objectives. In order to investigate the possible role of Aleutian disease parvovirus (ADV) in decline of the species, a serologic survey was conducted from March 1996 to March 2002 in 420 free-ranging individuals of six species of small carnivores distributed in eight departments of southwestern France. Antibodies to ADV were detected in 17 of 75 American mink (Mustela vison), 12 of 99 European mink, 16 of 145 polecats (Mustela putorius), four of 17 stone martens (Martes foina), one of 16 pine martens (Martes martes), and three of 68 common genets (Genetta genetta). Seroprevalence was significantly higher in American mink than in other species. Seropositive individuals with gamma globulin levels >20% were observed in four European mink, four American mink, two stone martens, and one pine marten. Geographic distribution of positive animals indicates the virus has spread to all areas where European mink are found. Furthermore, a trend of increasing prevalence seems to appear in Mustela sp. sympatric with American mink. Although further investigations are necessary to evaluate the role of ADV in decline of European mink, evidence of the virus in the wild at the levels found in our study has implications for conservation of this species.     

A species distribution model for pine marten (<Emphasis Type="Italic">Martes martes</Emphasis>) in the least forested region of Europe

Species distribution modelling is a useful technique that provides data on factors that can influence a species range, identify high suitability areas and model future scenarios. The pine marten (Martes martes) has undergone major historical declines in abundance and distribution in Northern Ireland, similar to that which has occurred throughout its range. Currently, the species is in a phase of range expansion in Northern Ireland, in what is the least forested landscape in Europe. To assess the suitability of this environment for pine marten re-establishment, presence only distribution data combined with landcover data at a 10-km scale were used in a species distribution modelling study using Maxent. The results indicated that approximately 32% (4500 km²) of the land area of Northern Ireland had a high probability of pine marten occurrence. Pine marten distribution was positively associated with the extent of conifer forest landcover types, which also had the highest single attribute contribution to the model. Landcover types that were negatively associated with pine marten distribution included the extent of open, dwarf and urban areas.     

On the ratio of phenotype and genotype of sable and pine marten in sympatry zone in the Northern Urals

Analysis of allele frequencies of nine nuclear DNA microsatellite loci in the sable (Martes zibellina) and pine marten (M. martes) demonstrated that these species from allopatric parts of the area differ with a high degree of significance, while hybridization regularly occurs between them in the sympatry zone in the Northern Urals. In total, populations of the sable and pine marten maintain genetic isolation in the sympatry area; however, individual phenotypes do not always correlate with their specific (or hybrid) belonging, which is determined by a genetic method.     

Guardian or threat: does golden eagle predation risk have cascading effects on forest grouse?

Previous studies on intraguild predation have mainly focused on within-class assemblages, even though avian top predators may also influence mammalian mesopredator prey. By using nation-wide long-term data from Finland, northern Europe, we examined the impacts of golden eagles (Aquila chrysaetos) together with red foxes (Vulpes vulpes) and pine martens (Martes martes) on forest-dwelling herbivores, black grouse (Tetrao tetrix) and hazel grouse (Tetrastes bonasia). We hypothesized that eagles may alleviate the overall predation pressure on grouse by imposing intraguild predation risk on mesopredators. The predation impact of eagle was modelled using eagle density estimates and distance to eagle nest. Wildlife triangle counts were used as predation impact proxies of mammalian mesopredators and as measures of response in grouse. Our results show that eagle density correlated negatively with black grouse abundance indices while being positively associated with the proportion of juveniles in both grouse species, irrespective of the abundance of mesopredators. Yet, foxes and martens alone had a negative effect on the abundance indices and the proportion of young in the two grouse species. This suggests that the possible cascading effects of eagles are not mediated by decreased mesopredator numbers, but instead by fear effects. Alternatively, they may be mediated by other species than fox or marten studied here. In conclusion, we found support for the hypothesis that eagles provide protection for juvenile black and hazel grouse, whereas they are a threat for adult grouse. This important information helps us to better understand the role of avian top predators in terrestrial ecosystems.     

Population aspects of sexual dimorphism in Mustelidae from the example of four species (Mustela lutreola, Neovison vison, Mustela putorius, and Martes martes)

Size sexual dimorphism was studied on 695 crania of four species of the Mustelidae. According to the degree of increasing differences between sexes, the species were arranged in the following order: common marten (Martes martes), European mink (Mustela lutreola), American mink (Neovison vison), and black polecat (Mustela putorius). The value of dimorphism characterizes the ecological flexibility of species and is an integrated population characteristic. It was demonstrated that M. martes occupies a specific and relatively narrow ecological niche of the forest ecosystem and joins weak competitive relations with smaller species of Mustelidae. The level of sexual dimorphism in M. lutreola and N. vison, as well as M. putorius, reflects the tension of their interspecific relationships in a given territory. A high level of sexual dimorphism in M. putorius is caused by further divergence of the ecological niches of males and females, being a compensatory mechanism, which mitigates the consequences of toughened environmental requirements.     

Genetic structure of the sable <Emphasis Type="Italic">Martes zibellina</Emphasis> L. populations from Magadan oblast as inferred from mitochondrial DNA variation

Restriction polymorphism of the mtDNA cytochrome b gene was studied in nine sable Martes zibellina L. populations from three introduction foci of Khabarovsk and Kamchatka sables in Magadan oblast: Olya, Kolyma, and Omolon. For comparison, similar studies were performed with the populations of central Kamchatka and Khabarovsk krai. In total, 444 DNA specimens were examined. Three mtDNA haplotypes (A, B, and C) proved to occur at various frequencies in the populations under study. The sable population system displayed high differentiation (F _ST = 22.3%). The populations of the Olya focus were most similar genetically to the populations of Kamchatka; those of the Omolon focus were similar to the Khabarovsk populations, and those of the Kolyma focus occupied an intermediate place. The observed spatial heterogeneity of the sable populations of Magadan oblast was explained in terms of the formation of the introduction foci of Kamchatka and Khabarovsk sables, starting from the 1950s.     

On Certain Properties of Water and Energy Metabolism in Representatives of Martes and Mustela Genera (Mammalia: Mustelidae)

The quantities of consumed food and water, quantity and moisture contents of faeces as well as quantity and concentration of excreted urine were determined in representatives of Martes—European pine marten (M. martes) and sable (M. zibellina)—as well as in polecat (Mustela putorius). Under the same cage conditions and free access to food, all three species have similar energy value of their daily diet. However, the level of drinking water consumption and the ratio between the daily total water and energy intake was reliably higher in both Martes species than in polecat. In addition, both marten and sable featured much higher rate of evaporation loss in the overall water balance and, consequently, a higher quantity of heat dissipated with evaporation as compared to polecat. Comparison of the obtained and previous data (Sokolov et al., 1995; Rozhnov, 1991) allowed us to propose that the mentioned differences are specific for representatives of Martes and Mustela genera irrespective of ecological specialization of particular species.     

A PCR-RFLP-based method to distinguish sable (<Emphasis Type="Italic">Martes zibellina</Emphasis>) and pine marten (<Emphasis Type="Italic">Martes martes</Emphasis>)

Species identification is an important issue in conservation and a particular focus for wildlife forensics. Molecular biological methods retain a unique power to differentiate between difficult samples that lack other identifiable characteristics. The pine marten (Martes martes) and sable (Martes zibellina) are closely related species with very similar pelage characteristics and are often difficult to distinguish from each other. The sable, however, in contrast to the pine marten, remains an endangered and protected animal in China with both hunting and fur trade strictly prohibited for this species. Here, we present a polymerase chain reaction-based restriction fragment length polymorphism method for distinguishing the two species. We sequenced a 638-bp fragment of cytochrome b gene in 39 sables, 68 pine martens, and 10 stone martens and identified all variable nucleotides. A new primer pair was subsequently designed to amplify a 316-bp fragment containing restriction sites of enzyme BseG I and BamH I that are different among martens. When the fragment was cut using BseG I, the resulting restriction pattern was identical in the sable and pine marten, but differed from all other martens. When cut using BamH I, the fragment generated two diagnostic fragments in the sable which could distinguish them from pine martens. This method was valid for all haplotypes of sable and pine marten thus far identified and has high potentially applicability for the identification of the two species.     

Widespread distribution of Pine martens (<Emphasis Type="Italic">Martes martes</Emphasis>) in a fragmented suburban landscape

Pine martens (Martes martes) are forest specialists that depend either on large patches of forest or on the absence of barriers between smaller forest patches. It thus seems likely that they would disappear from landscapes with heavily fragmented forests and a high density of presumptive barriers that are typical of Central Europe. We studied the distribution of pine martens in a suburban landscape characterised by fragmented forests and a high density of presumptive barriers (e.g. housing areas, roads). We assessed the presence of pine martens using camera traps in a sample of 170 1?×?1-km quadrats and used occupancy modelling to account for imperfect detection. We found an almost complete and countrywide distribution of the pine marten. Larger roads and housing areas were not negatively related to its current distribution as we predicted. We conclude that pine martens are capable to survive in some heavily fragmented landscapes.     

Non-invasively determined multi-site variation in pine marten <Emphasis Type="Italic">Martes martes</Emphasis> density,a recovering carnivore in Europe

Pine martens (Martes martes) are subject to national and international conservation legislation throughout most of their European range. Yet population density and abundance estimates, which are a key component of effective conservation management, are lacking in many countries. In this study, a large-scale non-invasive survey was undertaken in 14 forested study sites throughout Ireland to assess variation in pine marten density and abundance. Pine marten hair samples were collected in each study site and analysed using genetic techniques to determine individual identity data. Density and abundance estimates were obtained using spatially explicit capture-recapture models and CAPWIRE. Across all study sites, a total of 93 individual pine marten were identified and captured 217 times. Estimated pine marten density varied from 0 to 2.60 individuals per km² of forested habitat, with all but a single site having estimated densities of ≤1 pine marten per km² of forest habitat. Mean population abundance estimates across all study sites ranged from 0 to 27 individuals. Spatially explicit capture-recapture models on combined data across all 14 study sites provided a mean density estimate of 0.64 (95% CI 0.49–0.81). Combining this with data on the current distribution and estimated area of forest habitat occupied by the species in Ireland, the total pine marten population abundance of pine marten in Ireland was estimated at 3043 (95% CI 2330–3852) individuals. This research has conducted the largest scale investigation of pine marten density and abundance in any part of its global distribution and provided an improved basis for future population assessment and monitoring of this species.