Sorex Araneus Research Articles

Chromosome Synapsis and Recombination in Male Hybrids between Two Chromosome Races of the Common Shrew (Sorex araneus L., Soricidae, Eulipotyphla).

Hybrid zones between chromosome races of the common shrew (Sorex araneus) provide exceptional models to study the potential role of chromosome rearrangements in the initial steps of speciation. The Novosibirsk and Tomsk races differ by a series of Robertsonian fusions with monobrachial homology. They form a narrow hybrid zone and generate hybrids with both simple (chain of three chromosomes) and complex (chain of eight or nine) synaptic configurations. Using immunolocalisation of the meiotic proteins, we examined chromosome pairing and recombination in males from the hybrid zone. Homozygotes and simple heterozygotes for Robertsonian fusions showed a low frequency of synaptic aberrations (<10%). The carriers of complex synaptic configurations showed multiple pairing abnormalities, which might lead to reduced fertility. The recombination frequency in the proximal regions of most chromosomes of all karyotypes was much lower than in the other regions. The strong suppression of recombination in the pericentromeric regions and co-segregation of race specific chromosomes involved in the long chains would be expected to lead to linkage disequilibrium between genes located there. Genic differentiation, together with the high frequency of pairing aberrations in male carriers of the long chains, might contribute to maintenance of the narrow hybrid zone.

Evaluation of the physiological activity of venom from the Eurasian water shrew Neomys fodiens

BackgroundAnimal toxins can have medical and therapeutic applications. Principally, toxins produced by insects, arachnids, snakes and frogs have been characterized. Venomous mammals are rare, and their venoms have not been comprehensively investigated. Among shrews, only the venom of Blarina brevicauda has been analysed so far, and blarina toxin has been proven to be its main toxic component. It is assumed that Neomys fodiens employs its venom to hunt larger prey. However, the toxic profile, properties and mode of action of its venom are largely unknown. Therefore, we analysed the cardio-, myo- and neurotropic properties of N. fodiens venom and saliva of non-venomous Sorex araneus (control tests) in vitro in physiological bioassays carried out on two model organisms: beetles and frogs. For the first time, we fractionated N. fodiens venom and S. araneus saliva by performing chromatographic separation. Next, the properties of selected compounds were analysed in cardiotropic bioassays in the Tenebrio molitor heart.ResultsThe venom of N. fodiens caused a high decrease in the conduction velocity of the frog sciatic nerve, as well as a significant decrease in the force of frog calf muscle contraction. We also recorded a significant decrease in the frog heart contractile activity. Most of the selected compounds from N. fodiens venom displayed a positive chronotropic effect on the beetle heart. However, one fraction caused a strong decrease in the T. molitor heart contractile activity coupled with a reversible cardiac arrest. We did not observe any responses of the insect heart and frog organs to the saliva of S. araneus. Preliminary mass spectrometry analysis revealed that calmodulin-like protein, thymosin β-10, hyaluronidase, lysozyme C and phospholipase A2 are present in the venom of N. fodiens, whereas thymosin β4, lysozyme C and β-defensin are present in S. araneus saliva.ConclusionOur results showed that N. fodiens venom has stronger paralytic properties and lower cardioinhibitory activity. Therefore, it is highly probable that N. fodiens might use its venom as a prey immobilizing agent. We also confirmed that S. araneus is not a venomous mammal because its saliva did not exhibit any toxic effects.

Accumulation of Heavy Metals by Small Mammals the Background and Polluted Territories of the Urals

Abstract Accumulation of heavy metals (Cu, Zn, Cd) in hemopoietic-competent organs of ecologically contrast species of small mammals (Clethrionomys glareolus, Sorex araneus, Apodemus uralensis) from natural populations of the Middle and South Urals were considered. The content of exogenous and essential trace elements in animal tissues (a liver, kidney, a spleen) was determined by atomic absorption spectroscopy. It has been shown that bioaccumulation of heavy metals in organs of insectivores significantly differs from it of bank voles and wood mice. The smallest total content of heavy metals is shown in wood mice in technogenic territories of the Middle Urals. The submitted data demonstrate the competitive mechanism of the Cu, Zn, Cd. The increased concentrations of endogenous trace elements (copper, zinc) in relation to a toxicant (cadmium), other things being equal, reduce cadmium accumulation level in the tissues Sorex araneus.

Diet of shrews (Soricidae) in urban environment (Nitra, Slovakia)

To understand the food demand of shrews, it is necessary to conduct a comprehensive study of their environment. Therefore, the main aim of this paper is to discover the food composition of shrew and basic differences between three urban environments within Nitra (pericentral, peripheral and suburban). The research included continuous trapping of shrews in Nitra’s urban environments between 2013 and 2015. In total, 70 shrew specimens from four species were analysed: Crocidura suaveolens (43ex.), Crocidura leucodon (5ex.), Sorex araneus (19ex.) and Sorex minutus (3ex.). Overall, it was feasible to identify food components in 78.6% of samples taken from the gastrointestinal tracts of the trapped shrews, with the remaining samples (21.4%) having been completely digested. The Diptera larvae (family Bibionidae and Stratiomyidae), Coleoptera (most frequently occurring in Staphylinidae and Curculionidae families) were discovered to have been the dominant components in the shrews’ food demand. The research also showed a high abundance of Chilopoda (Lithobidae) and Diplopoda (Julidae) in the gastrointestinal tract content as well as significant similarity with respect to food preferences between Sorex araneus, Crocidura suaveolens and to a limited extent also Crocidura leucodon. However, there was confirmation of changes in the food spectrum of shrew species over annual periods, too.

Distinctive features of hepatocytes in five small mammal species (insectivores and rodents): taxonomic versus ecological specificity

Morphometric parameters of hepatocytes have been studied in five small mammal species with different ecological specificity from two taxonomic groups: a surface-dwelling insectivore (the common shrew, Sorex araneus), a subterranean insectivore (the European mole, Talpa europaea), surface-dwelling rodents (the bank vole, Myodes glareolus and herb field mouse, Apodemus uralensis) and a subterranean rodent (the northern mole vole, Ellobius talpinus). The results show that the hepatocytes of the European mole differ markedly from those of all other species, being characterized by smaller size and nuclear area, low anisocytosis and anisokaryosis, the almost complete absence of binuclear cells and, on the other hand, high nuclear–cytoplasmic ratio and packing density. The common shrew differs from the European mole containing a relatively high proportion of binuclear hepatocytes, and the size of hepatocytes in this species is smaller than in rodents. Differences in the parameters of these cells between rodents are minimal or absent. The differences observed in the characteristics of hepatocytes between the above species cannot be explained solely by either taxonomic or ecological specificity. Comparative research involving a greater number of closely related species (at the levels of families and orders) is needed to reveal and evaluate the taxonomic and ecological specificity of hepatocytes in greater detail.

Small mammal community response to early meadow\u2013forest succession

BackgroundWith farmland afforestation becoming common policy in many European Union countries, we studied how early forest succession (from meadow to young stand) influences small mammal species composition, diversity, abundance and biomass. Despite numerous investigations into forest succession, almost no attention has been given to the small mammal community change in the early-successional forest ecosystems, starting with the pre-forest habitat and ending with stand formation and the establishment of tree dominance. We compared small mammal communities in meadows at the initial stage of regrowth (with saplings less than 10 cm in height), in young forest (5–10 years old) and more advanced forest (15–20 years) in both cases of human-induced forest succession, where the trees had been planted, and natural forest succession, where natural regrowth of meadows had occurred.ResultsThe greatest diversity of small mammal species was recorded in the meadow (H = 2.95), with a lower diversity found in the young forest (H = 2.61) and even lower in the advanced forest (H = 2.04), the last habitat being the most monodominantic. The order of species dominance from Microtus sp. (M. arvalis, M. agrestis), Myodes glareolus, Apodemus flavicollis, Sorex araneus, A. agrarius in the meadow changed to M. glareolus, S. araneus, M. arvalis, M. agrestis in the young forest and to M. glareolus, A. flavicollis, S. araneus in the advanced forest. The lowest relative abundance of small mammals was recorded in the meadow (18.19 ± 2.27 ind. Per 100 trap-days), with Microtus voles being the most abundant. Relative abundance was higher in the young forest (22.72 ± 2.25 ind. Per 100 trap-days), with Myodes glareolus being the most abundant (7.59 ± 0.96 ind. Per 100 trap-days) and at its highest in the advanced forest (23.91 ± 2.77 ind. Per 100 trap-days), again with M. glareolus being the most abundant (15.54 ± 2.35 ind. Per 100 trap-days).ConclusionsThus, our analysis suggests that that during early meadow-forest succession, the diversity of the small mammal community declines – the number of species decreases as typical meadow species are lost due to the transformation of the habitat and one or a few species became dominants. However, the relative abundance of the small mammals increases. Biological indices of small mammal communities differed between natural and human-induced meadow-forest succession.

Parastrongyloides spp. nov. (Nematoda: Rhabditoidea: Strongyloididae) from the small intestine of a monotreme from Australia and a marsupial from the Republic of Colombia

ABSTRACTTwo new species of Parastrongyloides Morgan, 1928 (Nematoda: Rhabditoidea: Strongyloididae) are described, P. tachyglossi, from the small intestine of the short-beaked echidna, Tachyglossus aculeatus (Shaw, 1792) from southeastern New South Wales and northern Queensland and P. caenolesti from the small intestine of the common grey or dusky shrew opossum, Caenolestes fuliginosus (Tomes, 1863) from Parames du Puruce, the Republic of Colombia. The two new species are distinguished from each other by the position of the two pairs of caudal papillae of P. tachyglossi immediately pre- and post-cloacal in contrast to those in P. caenolesti which are distant from the cloacal aperture and by the generally smaller sizes of males and females of P. caenolesti and the presence of a minute terminal papilla or spine on the tail tip of male P. tachyglossi. They are distinguished from seven of the eight known species of Parastrongyloides by the absence of a single, median, dome-shaped papilla anterior to the cloacal opening in males and by the number and distribution of the other pre- and post-cloacal papillae in the male. The eighth species, Parastrongyloides skrjabini Petrov & Savinov, 1959 has no pre- or post-cloacal papillae. These represent the first species of Parastrongyloides to be described from a monotreme and from a South American marsupial.

Evolutionary history and phylogeographic relationships of shrews from Sorex araneus group.

Shrews of the Sorex genus are an evolutionarily successful group that includes more than 77 species widely distributed in Eurasia and North America. The genus is one of the rare cases where karyotypic changes reflect well the evolutionary relationships among its species. The taxa showing the greatest variation in karyotype are usually classified into the Sorex araneus group. Its evolution was associated with chromosomal rearrangements, which could have promoted fast diversification of this group into many chromosomal races and species. These processes were additionally complicated by introgressions of mitochondrial DNA, which made the evolutionary history of this group quite complex and difficult to infer. To tackle the problem, we performed multi-method phylogenetic analyses based on mitochondrial cytochrome b that is considered a good molecular marker available for many representatives of Sorex. The results were compared with phylogenies based on chromosomal rearrangement data and put into temporal and spatial context using molecular dating and historical biogeography methods. We complemented the study with the estimation of diversification rates within the S. araneus group as well as comparing the results with paleontological records and climatic oscillations within the last 4 million years. Based on the gathered data, we proposed a hypothetical scenario for the evolution and geographic dispersion of species belonging to the S. araneus group. The shrews began to diversify about 2.7 million years ago in Eurasia and then migrated at least twice to North America. The evolution of shrews was driven by Pleistocene glacial and interglacial cycles, which increased their speciation rate and the emergence of new lineages. The migrations of populations were accompanied by introgressions of mitochondrial DNA into native shrews and occurred at least twice.

Study of male-mediated gene flow across a hybrid zone in the common shrew (Sorex araneus) using Y chromosome.

Despite many studies, the impact of chromosome rearrangements on gene flow between chromosome races of the common shrew (Sorex araneus Linnaeus, 1758) remains unclear. Interracial hybrids form meiotic chromosome complexes that are associated with reduced fertility. Nevertheless comprehensive investigations of autosomal and mitochondrial markers revealed weak or no barrier to gene flow between chromosomally divergent populations.In a narrow zone of contact between the Novosibirsk and Tomsk races hybrids are produced with extraordinarily complex configurations at meiosis I. Microsatellite markers have not revealed any barrier to gene flow, but the phenotypic differentiation between races is greater than may be expected if gene flow was unrestricted. To explore this contradiction we analyzed the distribution of the Y chromosome SNP markers within this hybrid zone. The Y chromosome variants in combination with race specific autosome complements allow backcrosses to be distinguished and their proportion among individuals within the hybrid zone to be evaluated. The balanced ratio of the Y variants observed among the pure race individuals as well as backcrosses reveals no male mediated barrier to gene flow. The impact of reproductive unfitness of backcrosses on gene flow is discussed as a possible mechanism of the preservation of race-specific morphology within the hybrid zone.

Dampening of population cycles in voles affects small mammal community structure, decreases diversity, and increases prevalence of a zoonotic disease.

Long‐term decline and depression of density in cyclic small rodents is a recent widespread phenomenon. These observed changes at the population level might have cascading effects at the ecosystem level. Here, we assessed relationships between changing boreal landscapes and biodiversity changes of small mammal communities. We also inferred potential effects of observed community changes for increased transmission risk of Puumala virus (PUUV) spread, causing the zoonotic disease nephropatica epidemica in humans. Analyses were based on long‐term (1971–2013) monitoring data of shrews and voles representing 58 time series in northern Sweden. We calculated richness, diversity, and evenness at alpha, beta, and gamma level, partitioned beta diversity into turnover (species replacement) and nestedness (species addition/removal), used similarity percentages (SIMPER) analysis to assess community structure, and calculated the cumulated number of PUUV‐infected bank voles and average PUUV prevalence (percentage of infected bank voles) per vole cycle. Alpha, beta, and gamma richness and diversity of voles, but not shrews, showed long‐term trends that varied spatially. The observed patterns were associated with an increase in community contribution of bank vole (Myodes glareolus), a decrease of gray‐sided vole (M. rufocanus) and field vole (Microtus agrestis) and a hump‐shaped variation in contribution of common shrew (Sorex araneus). Long‐term biodiversity changes were largely related to changes in forest landscape structure. Number of PUUV‐infected bank voles in spring was negatively related to beta and gamma diversity, and positively related to turnover of shrews (replaced by voles) and to community contribution of bank voles. The latter was also positively related to average PUUV prevalence in spring. We showed that long‐term changes in the boreal landscape contributed to explain the decrease in biodiversity and the change in structure of small mammal communities. In addition, our results suggest decrease in small mammal diversity to have knock‐on effects on dynamics of infectious diseases among small mammals with potential implications for disease transmission to humans.

Vegetation cover and small mammals as the components of biocoenosis in the conditions of the Volga Upland

The study of the nature reserve oak forest near the village of Pelya-Khovanskaya ecosystem was done in the region of Nizhny Novgorod. The investigated wood is unique for its complex structure. It is situated in the forest-steppe zone, characterized by a high species diversity of small mammals and vegetation, which indicates the complexity of trophic and spatial connections. Several series of sample plots were described: 41 of 2020 m and a number of 11 m sites, totaling 300. Abundance of species by Brown-Blanke scale and the number of specimens of adolescence were specified for each 1 sq. m. plot. Mammals were trapped with the help of trapping grooves and transects method. Vegetation cover is characterized by the presence of a clear intra-differentiation as well as the existence of two basic ecologo-coenotic groups/cores - the nemoral (with Pulmonaria obscura Dum. as the center species of the core) and the meadow-fringe. The most distinct group is formed by forest-shoot species. It can be explained by more forest-steppe rather than nemoral nature of vegetation. Small mammals are represented by the following species: common and small shrews, small forest mouse, yellow-throated and field mice and harvest mouse, vole-housekeeper, common, plowed and red voles, European mole. Two species among them - vole-housekeeper and mouse-baby - are listed in the Red Book of the Nizhny Novgorod Region. Matching burrows of mouse-like rodents with soil richness with nitrogen and humidity, two well-defined peaks are observed. The greatest number of burrows is found in places where the soil is high in nitrogen. Moles were found in areas with a large projective coating of Primula veris: coefficient Spearman rank 0,50. There was a negative correlation of the number of moles and vegetation covering of Pyrethrum corymbosum (-0,46), which is the marker of the driest parts in the forest. In general, the nature reserve oak forest near the village of Pelya-Khovanskaya is of considerable interest, both from botanical and from zoological point of view. Long-term studies of biocoenosis will allow to monitor the facility and to correct the proposed protective measures.

Density-dependent processes determine the distribution of chromosomal races of the common shrew Sorex araneus (Lipotyphla, Mammalia)

The common shrew is subdivided into 74 chromosomal races, widely distributed in the postglacial area from the Britain Islands to Lake Baikal. Based on 1969 karyotypes from 216 localities, we present for the first time a map of ranges of 25 chromosomal races (except the Altai race) currently known in Russia. We revealed two centers of high karyotypic diversity: the western (near Baltic Sea) and the eastern (near Baikal Lake). The studied races were categorized as small-, medium-, and large-range races, and small-range races concentrated around those two centers of karyotypic diversity. We did not find any significant association between race range size and ecological zone, latitude, or the ambient temperature. Physical barriers, such as Ural Mountain or rivers, do not limit race distribution. The width of rivers that divide a range of a single race or ranges of two different races does not differ. We supposed that the occupation of an area by a race could limit the invasion of a different race from an adjacent area and expansion of its range, thus contributing to race parapatric distribution alone without additional effects of physical barriers. Based on karyotype similarity and geographic localization, we combined races into four “karyotypic chains,” in which the races can be derived from one another consequently by a single chromosomal translocation. The present distribution of the common shrew races in Russia supports the idea that it has resulted from recolonization from refugia governed by the density-dependent processes.

Karyotypic differentiation of populations of the common shrew Sorex araneus L. (Mammalia) in Belarus

The common shrews, Sorex araneus Linnaeus, 1758, inhabiting the territory of Belarus, are characterized by a significant variation in the frequency of Robertsonian (Rb) translocations. The frequency clines for translocations specific of three chromosome races: the West Dvina (gm, hk, ip, no, qr), Kiev (g/m, hi, k/o, n, p, q, r), and Białowieża (g/r, hn, ik, m/p, o, q) have already been studied in this territory. In this communication we report new data on polymorphic populations with Rb metacentrics specific of the Neroosa race (go, hi, kr, mn, p/q) in south-eastern Belarus, analyse the distribution of karyotypes in southern and central Belarus and draw particular attention to the fixation of the acrocentric variants of chromosomes in this area. The results show that certain Rb metacentrics specific of the Neroosa, West Dvina, Kiev, and Białowieża races (namely, go and pq; ip; ko; hn and ik, respectively) are absent in many polymorphic populations. Thus, the karyotypic differentiation of S. araneus in the studied area is determined by unequal spread of different Rb translocations and by fixation of acrocentric variants of specific chromosomes.

Abundance of Common Shrew (Sorex Araneus) in Selected Forest Habitats of Moravia (Czech Republic)

Abundance of common shrew (Sorex araneus) was evaluated on selected forest sites in Moravia, Czech Republic. Six types of habitats were assessed: forest clearings and mature forests in lowlands (173 – 233 m), uplands (360 – 600 m), and mountains (600 – 1200 m). Data were collected over five‑year‑long periods; 2006 – 2010 (uplands) and 2007 – 2011 (lowlands and mountains). Small terrestrial mammals were captured using snap traps laid in lines. In total, 200 individuals of common shrew were trapped. Relative abundance among different habitats was statistically evaluated. The highest relative abundance was found in mountain forest clearings (n = 132, rA = 0.719). Lower abundance was in upland forest clearings (n = 15, rA = 0.384), in mature mountain forests (n = 32, rA = 0.355), and in the lowland forest clearings (n = 9, rA = 0.109). The lowest abundance was in mature upland forests (n = 9, rA = 0.031) and in mature lowland forests (n = 3, rA = 0.011). Differences between sites were statistically significant. Among all altitudes, shrew populations in plantations were significantly more numerous than those in mature forests. Mountain forest clearings with dense herb layer proved to be the most suitable habitat while mature lowland forests with less developed herbaceous layer were the least suitable. Forest clearings proved to be an important refuge for the populations of common shrew.

Studying hunting behaviour in the striped field mouse using data compression

We compare predatory behaviour towards a mobile insect in three species of small mammals: the granivorous striped field mouse, the insectivorous common shrew and the Norway rat (a generalist). The striped field mouse displays a surprisingly efficient hunting stereotype. We apply the data compression method (Ryabko et al. Theory Comput Syst 52:133–147, 2013) to compare the complexity of hunting behavioural patterns and to evaluate the flexibility of stereotypes and their succinctness. Norway rats demonstrated the highest level of complexity of hunting behaviour, with the highest proportion of ‘auxiliary’ and ‘noise’ elements and relatively low proportion of ‘key’ elements in their behaviours. The predominance of ‘key’ elements resulted in similarly low levels of complexity of hunting stereotypes in striped field mice and shrews. The similarity between hunting stereotypes of the insectivorous shrew and the granivorous striped field mouse enables us to argue about evolutionary roots of hunting behaviour in small mammals. We show that this method is a useful tool for comparing ethograms as ‘biological texts’.

Social personality: a more social shrew species exhibits stronger differences in personality types

Animal personalities have been studied extensively in the last decade. It is still not entirely understood, however, how different personalities evolve and persist. The social niche specialization hypothesis suggests that in group-living animals the combination of social conflicts and alternative options on how to deal with them are of key importance for the development and evolution of animal personality. Here we predicted that, following the social niche specialization hypothesis, a more social species should have more pronounced personality differences. We tested this prediction using four species of shrews that differ in ecology and sociability. Three species (Neomys fodiens, Sorex araneus and Sorex minutus) are strictly solitary outside the breeding season; the fourth species (Neomys anomalus) is intraspecifically more tolerant and able to live in groups. These four species offer a good model to assess our questions as N. anomalus can, in many other respects (e.g. body size, habitat, foraging mode), be considered as an ‘in-between’ species. We tested individuals of all species for their solitary activity and their activity and agonistic behaviour in within- and between-species dyadic encounters. We found that individuals of N. anomalus, but not the other species tested, showed consistent behavioural variation in agonistic behaviour. Consistent individual differences in activity were, however, also present in other species and activity was further correlated between the different contexts in all tested species. Finding more pronounced personality differences in N. anomalus than in the other, less sociable species supports the hypothesis that social niche specialization can influence the evolution of animal personalities.

Leptospira spp. in Small Mammals from Areas with Low and High Human Hantavirus Incidences in South-West Germany.

Leptospirosis is caused by Leptospira spp. and is considered the most widespread zoonotic disease worldwide. It mimics nephropathia epidemica in humans, a disease mainly caused by Puumala hantavirus (PUUV). Small mammals are reservoirs for Leptospira spp. and PUUV. Seewis virus (SWSV) is a shrew-borne hantavirus with unknown pathogenicity. The objective of this study was to estimate the prevalence for Leptospira spp. and the frequency of Leptospira-hantavirus co-infections in small mammals collected at locations with high and low incidences in humans. In 2012 and 2013, 736 small mammals belonging to seven species (Apodemus flavicollis, Microtus agrestis, Microtus arvalis, Myodes glareolus, Sorex araneus, S. coronatus, and S. minutus) were collected at four high incidence sites (H1-H4) and four low (L1-L4) incidence sites for PUUV infection in humans. Kidney-derived DNA samples were tested for Leptospira spp. by real-time PCR targeting the lipl 32 gene and further analyzed by duplex PCR targeting the flaB and the secY genes. For the detection of Seewis virus, lung-derived DNA was tested via RT-PCR targeting the nucleocapsid gene. Altogether, 42 of the 736 small mammals including 27 of 660 bank voles and 11 of 66 shrews, were positive for Leptospira spp., while Sorex spp. (14.7%) showed significantly higher prevalences compared to bank voles (4.1%). Detected Leptospira spp. were pathogenic species other than L. kirschneri. Significantly more Leptospira-positive bank voles were found at H sites than at L sites. Altogether 22.2% of positive bank voles were infected with PUUV. Double infection of PUUV and Leptospira spp. occurrence in bank voles is 1.86 times (OR = 1.86; 95% CI: 0.72-4.73) more likely than infections with each pathogen separately. Leptospira- positive bank voles are focally positively associated with PUUV infection in bank voles and with human hantavirus cases. It should be considered that shrews may serve as Leptospira spp. reservoirs.

The enzootic life-cycle of Borrelia burgdorferi (sensu lato) and tick-borne rickettsiae: an epidemiological study on wild-living small mammals and their ticks from Saxony, Germany

BackgroundBorrelia burgdorferi (sensu lato) and rickettsiae of the spotted fever group are zoonotic tick-borne pathogens. While small mammals are confirmed reservoirs for certain Borrelia spp., little is known about the reservoirs for tick-borne rickettsiae. Between 2012 and 2014, ticks were collected from the vegetation and small mammals which were trapped in Saxony, Germany. DNA extracted from ticks and the small mammals’ skin was analyzed for the presence of Rickettsia spp. and B. burgdorferi (s.l.) by qPCR targeting the gltA and p41 genes, respectively. Partial sequencing of the rickettsial ompB gene and an MLST of B. burgdorferi (s.l.) were conducted for species determination.ResultsIn total, 673 small mammals belonging to eight species (Apodemus agrarius, n = 7; A. flavicollis, n = 214; Microtus arvalis, n = 8; Microtus agrestis, n = 1; Mustela nivalis, n = 2; Myodes glareolus, n = 435; Sorex araneus, n = 5; and Talpa europaea, n = 1) were collected and examined. In total, 916 questing ticks belonging to three species (Ixodes ricinus, n = 741; Dermacentor reticulatus, n = 174; and I. trianguliceps, n = 1) were collected. Of these, 474 ticks were further investigated. The prevalence for Rickettsia spp. and B. burgdorferi (s.l.) in the investigated small mammals was 25.3 and 31.2%, respectively. The chance of encountering Rickettsia spp. in M. glareolus was seven times higher for specimens infested with D. reticulatus than for those which were free of D. reticulatus (OR: 7.0; 95% CI: 3.3–14.7; P < 0.001). In total, 11.4% of questing I. ricinus and 70.5% of D. reticulatus were positive for Rickettsia spp. DNA of B. burgdorferi (s.l.) was detected only in I. ricinus (5.5%). Sequence analysis revealed 9 R. helvetica, 5 R. raoultii, and 1 R. felis obtained from 15 small mammal samples.ConclusionSmall mammals may serve as reservoirs for Rickettsia spp. and B. burgdorferi (s.l.). While the prevalence for Rickettsia spp. in M. glareolus is most likely depending on the abundance of attached D. reticulatus, the prevalence for B. burgdorferi (s.l.) in small mammals is independent of tick abundance. Dermacentor reticulatus may be the main vector of certain Rickettsia spp. but not for Borrelia spp.

Small Mammals in an Urban Area: Habitat Preferences and Urban-Rural Gradient in Nitra City, Slovakia

ABSTRACT The small mammal species were investigated in the urbanized environment of Nitra city (Slovakia) in a multiscale-approach: at habitat level and at landscape level (urban-rural gradient). Continuous comprehensive rodent samplings from 2012 to 2015 were conducted in ten study sites, classified into three urban zones (landscape level). The total effort comprised 1,250 specimens of 13 species (Microtus arvalis, Apodemus sylvaticus, A. flavicollis, A. uralensis, Clethrionomys (Myodes) glareolus, M. subterraneus, Micromys minutes, Mus spicilegus, M. musculus, Crocidura suaveolens, C. leucodon, Sorex araneus, S. minutus) gathered in 14950 trapxnights. Environmental variables (habitat level) at each site were processed in the Geographical Information System as a proportion of landscape units around the trapping line and by a phytosociological survey. At the habitat level, we found a relationship between the landscape habitat structure and each species of small mammals. Diversity, species richness and rel...

Woodland reserves within an urban agglomeration as important refuges for small mammals

Abstract The aim of the study was to determine the species richness (S, Chao- 1 index) and diversity (Shannon-Wiener H’ index, diversity profiles) of small mammal assemblages in woodland reserves in an urban agglomeration and to compare the similarity of assemblages (with the use of Ward’s method) in terms of proportions of small mammals connected to the habitats of different level of naturalness. The work was conducted from 2004-2015 at 9 woodland reserves in Warsaw (Poland). On the basis of the analysis of pellets of tawny owls Strix aluco, 2792 individuals were identified (24 species). Reserves supported from 7 to 16 of the small mammal species, the highest overall number of species estimated (Chao-1) was 19. Species present in every reserve were Apodemus flavicollis, A. agrarius, Rattus norvegicus, Sorex araneus and Talpa europaea. Least frequent were Microtus agrestis and M. subterraneus. Seven species of bats were detected. Species diversity was lower in the biggest forest complexes, where forest rodents dominated small mammal assemblage. The heterogeneity of habitats within reserve and in the surroundings, in combination with limited human-interference, resulted in an increase in the species diversity. Overall, the reserves under study were an important refuge for small mammals within the Warsaw agglomeration. However, safeguarding of adjacent areas against excessive anthropogenic change is needed and ecological corridors that link different areas need to be retained.