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differential behavioural and endocrine responses of common voles (microtus arvalis) to nest predators and resource competitors.adaptive behavioural strategies promoting co-occurrence of competing species are known to result from a sympatric evolutionary past. strategies should be different for indirect resource competition (exploitation, e.g., foraging and avoidance behaviour) than for direct interspecific interference (e.g., aggression, vigilance, and nest guarding). we studied the effects of resource competition and nest predation in sympatric small mammal species using semi-fossorial voles and shrews, which prey on v ...201324010574
gene flow and population structure of a common agricultural wild species (microtus agrestis) under different land management regimes.the impact of landscape structure and land management on dispersal of populations of wild species inhabiting the agricultural landscape was investigated focusing on the field vole (microtus agrestis) in three different areas in denmark using molecular genetic markers. the main hypotheses were the following: (i) organic farms act as genetic sources and diversity reservoirs for species living in agricultural areas and (ii) gene flow and genetic structure in the agricultural landscape are influence ...201323900396
deleterious consequences of antioxidant supplementation on lifespan in a wild-derived mammal.while oxidative damage owing to reactive oxygen species (ros) often increases with advancing age and is associated with many age-related diseases, its causative role in ageing is controversial. in particular, studies that have attempted to modulate ros-induced damage, either upwards or downwards, using antioxidant or genetic approaches, generally do not show a predictable effect on lifespan. here, we investigated whether dietary supplementation with either vitamin e (α-tocopherol) or vitamin c ( ...201323825087
a small-scale survey of hantavirus in mammals from eastern poland.samples of 30 dead small mammals each were collected on area 'a' located in eastern poland which is exposed to flooding by the vistula river, and on the area 'b', also located in eastern poland but not exposed to flooding. kidneys and livers of the mammals were examined by the pcr and nested pcr methods for the presence of hantavirus rna. out of 7 species of small mammals examined, the presence of hantaviruses was detected in 4 of them. hantavirus prevalence was low in apodemus agrarius (2.6%), ...201323772576
novel hantavirus in wildlife, united kingdom 201323750506
ljungan virus is endemic in rodents in the uk.ljungan virus is a recently identified member of the family picornaviridae that was isolated from bank voles in sweden. ljv has been associated with [corrected] type 1 diabetes-like symptoms and myocarditis in bank voles (myodes glareolus), and it has been suggested that it has zoonotic potential. here, we show for the first time that ljungan virus is prevalent (20-27 % positive by pcr) in four species of uk rodent (myodes glareolus [bank vole], apodemus sylvaticus [wood mouse], microtus agresti ...201423665770
seroprevalence of encephalitozoon cuniculi in wild rodents, foxes and domestic cats in three sites in the united kingdom.encephalitozoon cuniculi is an obligate intracellular microsporidian that is the causal agent of encephalitozoonosis, an important and emerging disease in both humans and animals. little is known about its occurrence in wildlife. in this study, serum samples from 793 wild rodents [178 bank voles (bv), 312 field voles (fv) and 303 wood mice (wm)], 96 foxes and 27 domestic cats from three study areas in the uk were tested for the presence of antibodies to e. cuniculi using a direct agglutination t ...201523607769
lysozyme activity in the plasma of rodents infected with their homologous trypanosomes.in this study the concentration of lysozyme in blood plasma of microtus agrestis, clethrinomys glareolus, apodemus sylvaticus, bk rats and outbred white mice before and after infection with culture forms of trypanosoma microti, t, evotomys, t. grosi, t. lewisi and t. musculi respectively was measured.201223323096
cryptic speciation in the field vole: a multilocus approach confirms three highly divergent lineages in eurasia.species are generally described from morphological features, but there is growing recognition of sister forms that show substantial genetic differentiation without obvious morphological variation and may therefore be considered 'cryptic species'. here, we investigate the field vole (microtus agrestis), a eurasian mammal with little apparent morphological differentiation but which, on the basis of previous sex-linked nuclear and mitochondrial dna (mtdna) analyses, is subdivided into a northern an ...201223163319
post-hoc pattern-oriented testing and tuning of an existing large model: lessons from the field vole.pattern-oriented modeling (pom) is a general strategy for modeling complex systems. in pom, multiple patterns observed at different scales and hierarchical levels are used to optimize model structure, to test and select sub-models of key processes, and for calibration. so far, pom has been used for developing new models and for models of low to moderate complexity. it remains unclear, though, whether the basic idea of pom to utilize multiple patterns, could also be used to test and possibly deve ...201223049882
identification of a new species of digenean notocotylus malhamensis n. sp. (digenea: notocotylidae) from the bank vole (myodes glareolus) and the field vole (microtus agrestis).notocotylus malhamensis n. sp. is described from the caecum of the bank vole (myodes glareolus) and the field vole (microtus agrestis) from malham tarn nature reserve in north yorkshire, uk. in total, 581 specimens were collected from rodents trapped at a wetland site (tarn fen) between july 2010 and october 2011 with a prevalence of 66·7% and mean intensity of 94·6 in the bank vole and 50% prevalence and a mean intensity of 4·3 in the field vole. this species appears to be most closely related ...201223036693
[functional features of microbial communities in the digestive tract of field voles (microtus rossiaemeridionalis and clethrionomys glareolus)].the nitrogen-fixating and cellobiohydrolase activity, the nitrogen (n) and carbon (c) contents, and the number of microorganisms in the prestomach, cecum, and colon of two vole species were studied: the southern vole (microtus rossiaemeridionalis) and the bank vole (clethrionomys glareolus), which is characterized by a mixed type of diet. the nitrogen-fixating activity in the cecum was found to be the highest in the voles compared with the mammals studied earlier. the seasonal dynamics of both n ...201622988758
rodent damage to natural and replanted mountain forest regeneration.impact of small rodents on mountain forest regeneration was studied in national nature reserve in the beskydy mountains (czech republic). a considerable amount of bark damage was found on young trees (20%) in spring after the peak abundance of field voles (microtus agrestis) in combination with long winter with heavy snowfall. in contrast, little damage to young trees was noted under high densities of bank voles (myodes glareolus) with a lower snow cover the following winter. the bark of deciduo ...201222666163
the interrelationship of mycophagous small mammals and ectomycorrhizal fungi in primeval, disturbed and managed central european mountainous forests.small forest dwelling mammals are considered to be major consumers and vectors of hypogeous ectomycorrhizal (ecm) fungi, which have lost the ability of active spore discharge. fungal spore dispersal by mycophagy is deemed an important process involved in forest regeneration, resilience and vitality, primarily based on evidence from australia and the pacific northwestern usa, but is poorly known for central european mountainous forests thus far. small mammal mycophagy was investigated by live tra ...201222466900
evidence for selection at cytokine loci in a natural population of field voles (microtus agrestis).individuals in natural populations are frequently exposed to a wide range of pathogens. given the diverse profile of gene products involved in responses to different types of pathogen, this potentially results in complex pathogen-specific selection pressures acting on a broad spectrum of immune system genes in wild animals. thus far, studies into the evolution of immune genes in natural populations have focused almost exclusively on the major histocompatibility complex (mhc). however, the mhc re ...201222364125
a comparative analysis of the mole vole sibling species ellobius tancrei and e. talpinus (cricetidae, rodentia) through chromosome painting and examination of synaptonemal complex structures in hybrids.a comparative genomic analysis was carried out in the mole vole sibling species ellobius tancrei and e. talpinus. performing fluorescent in situ hybridisation (zoo-fish) using chromosome paints from the field vole microtus agrestis showed no differences in the allocation of syntenic groups in the karyotypes of these sibling species. the only difference between their karyotypes was the position of the centromere in one pair of chromosomes, which is assumed to be the result of an inversion. to ver ...201222343488
spatio-temporal patterns of habitat use in voles and shrews modified by density, season and predators.1. although the intrinsic habitat preferences of a species can be considered to be fixed, the realized habitat use depends on the prevailing abiotic and biotic conditions. often the core habitats are occupied by dense and stable populations, while marginal habitats become occupied only at times of high density. in a community of interacting species, habitat uses of different species become inter-related, for example an increased density of a strong competitor forcing a weaker competitor to use m ...201222325037
significant interspecies differences in induction profiles of hepatic cyp enzymes by tcdd in bank and field voles.the gene expression and induction of cytochrome p450 (cyp)-enzymes following 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) peroral administration was studied in livers of two wild vole species-the bank vole (myodes glareolus) and the field vole (microtus agrestis). dioxin-sensitive c57bl/6 mouse was used as a reference. doses of 0.05, 0.5, 5.0, and 50 µg/kg were applied to ascertain a dose-response relationship, and the dose of 50 µg/kg was applied to study time course for up to 96 h. the cytochrom ...201122213473
guild composition and habitat use of voles in 2 forest landscapes in south-eastern norway.it is widely believed that intensive forestry has influenced small mammal population dynamics, and thereby the entire mammalian community in fennoscandian boreal forests. the nature of these impacts on the different species is subject to debate. we live-trapped voles between 2006 and 2009 in 2 commercially harvested forests in south-eastern norway. we investigated the variation in vole abundance among habitat types (e.g. mature forest and clear-cut) and the hypothesis that graminivorous species ...201122182322
natal dispersal in relation to population density and sex ratio in the field vole, microtus agrestis.in a sample of 240 juvenile field voles 8% of the males and 22% of the females reached sexual maturity within their natal home range. among individuals retrapped as adults, 58% of males and 23% of females had dispersed, i.e. had moved more than one home range diameter. the mean distance moved for males (58.5 m) exceeded that for females (28.6 m). male movement distances were negatively associated with total density, and with density of adult females, but not with male density. female movements w ...199022160104
asymmetric and differential gene introgression at a contact zone between two highly divergent lineages of field voles (microtus agrestis).secondary contact zones have the potential to shed light on the mode and rate at which reproductive isolation accumulates during allopatric speciation. we investigated the population genetics of a contact zone between two highly divergent lineages of field voles (microtus agrestis) in the swiss jura mountains. to shed light on the processes underlying introgression, we used maternally, paternally, and bi-parentally inherited markers. though the two lineages maintained a strong genetic structure, ...201222150868
genetic diversity in cytokines associated with immune variation and resistance to multiple pathogens in a natural rodent population.pathogens are believed to drive genetic diversity at host loci involved in immunity to infectious disease. to date, studies exploring the genetic basis of pathogen resistance in the wild have focussed almost exclusively on genes of the major histocompatibility complex (mhc); the role of genetic variation elsewhere in the genome as a basis for variation in pathogen resistance has rarely been explored in natural populations. cytokines are signalling molecules with a role in many immunological and ...201122039363
how predation and landscape fragmentation affect vole population dynamics.microtine species in fennoscandia display a distinct north-south gradient from regular cycles to stable populations. the gradient has often been attributed to changes in the interactions between microtines and their predators. although the spatial structure of the environment is known to influence predator-prey dynamics of a wide range of species, it has scarcely been considered in relation to the fennoscandian gradient. furthermore, the length of microtine breeding season also displays a north- ...201121829528
xenobiotic metabolism of bank vole (myodes glareolus) exposed to pcdds.previous studies in bank vole (myodes glareolus) and field vole (microtus agrestis) living at the old sawmill area contaminated by chlorinated dibenzo-p-dioxins and -furans (pcdd/fs) showed that these two relatively close species have a significant difference in their body burden of pcdd/fs, bank voles having significantly higher concentrations. the aim of this study was to clarify more comprehensively the basic xenobiotic metabolism in wild bank voles and examine whether pcdd exposure would aff ...201021787577
breeding state and season affect interspecific interaction types: indirect resource competition and direct interference.indirect resource competition and interference are widely occurring mechanisms of interspecific interactions. we have studied the seasonal expression of these two interaction types within a two-species, boreal small mammal system. seasons differ by resource availability, individual breeding state and intraspecific social system. live-trapping methods were used to monitor space use and reproduction in 14 experimental populations of bank voles myodes glareolus in large outdoor enclosures with and ...201121597944
rodents as sentinels for the prevalence of tick-borne encephalitis virus.abstract introduction: tick-borne encephalitis virus (tbev) causes one of the most important flavivirus infections of the central nervous system, affecting humans in europe and asia. it is mainly transmitted by the bite of an infected tick and circulates among them and their vertebrate hosts. until now, tbe risk analysis in germany has been based on the incidence of human cases. because of an increasing vaccination rate, this approach might be misleading, especially in regions of low virus circu ...201121548766
post-glacial partitioning of mitochondrial genetic variation in the field vole.genetic markers are often used to examine population history. there is considerable debate about the behaviour of molecular clock rates around the population-species transition. nevertheless, appropriate calibration is critical to any inference regarding the absolute timing and scale of demographic changes. here, we use a mitochondrial cytochrome b gene genealogy, based entirely on modern sequences and calibrated from recent geophysical events, to date the post-glacial expansion of the eurasian ...201121508032
natal conditions alter age-specific reproduction but not survival or senescence in a long-lived bird of prey.1. natal conditions and senescence are two major factors shaping life-history traits of wild animals. however, such factors have rarely been investigated together, and it remains largely unknown whether they interact to affect age-specific performance. 2. we used 27 years of longitudinal data collected on tawny owls with estimates of prey density (field voles) from kielder forest (uk) to investigate how prey density at birth affects ageing patterns in reproduction and survival. 3. natal conditio ...201121466554
the common shrew (sorex araneus): a neglected host of tick-borne infections?although the importance of rodents as reservoirs for a number of tick-borne infections is well established, comparatively little is known about the potential role of shrews, despite them occupying similar habitats. to address this, blood and tick samples were collected from common shrews (sorex araneus) and field voles (microtus agrestis), a known reservoir of various tick-borne infections, from sites located within a plantation forest in northern england over a 2-year period. of 647 blood sampl ...201121453011
the vicious circle and infection intensity: the case of trypanosoma microti in field vole populations.in natural populations, infection and condition may act synergistically to trigger a vicious circle: poor condition predisposes to host infections, which further reduce condition, and so on. if this vicious circle originates from a reduced resistance to infection, it will not only result in greater proneness to becoming infected of those that are in poorer condition, but it may also cause infections of higher intensity. here, we investigate the temporal relationship between host condition and in ...200921352763
effects of abundance on infection in natural populations: field voles and cowpox virus.detailed results on the dynamics of cowpox virus infection in four natural populations of the field vole, microtus agrestis, are presented. populations were sampled every 4 weeks (8 weeks in mid-winter) for 6 years. the purpose was to examine the relationships between overall or susceptible host abundance (n, s) and both the number of infected hosts (i) and the prevalence of infection (i/n). overall, both i and i/n increased with n. however, evidence for a threshold abundance, below which infect ...200921352750
tick-borne encephalitis virus in wild rodents in winter, finland, 2008-2009.rodents might maintain tick-borne encephalitis virus (tbev) in nature through latent persistent infections. during 2 subsequent winters, 2008 and 2009, in finland, we detected rna of european and siberian subtypes of tbev in microtus agrestis and myodes glareolus voles, respectively. persistence in rodent reservoirs may contribute to virus overwintering.201121192857
the analysis of immunological profiles in wild animals: a case study on immunodynamics in the field vole, microtus agrestis.a revolutionary advance in ecological immunology is that postgenomic technologies now allow molecular mediators defined in laboratory models to be measured at the mrna level in field studies of many naturally occurring species. here, we demonstrate the application of such an approach to generate meaningful immunological profiles for wild mammals. we sampled a natural field vole population across the year (n = 307) and developed a battery of cellular assays in which functionally different pro- an ...201121059128
trench fever: the field vole a possible origin. 191620768293
non-human primates in outdoor enclosures: risk for infection with rodent-borne hantaviruses.different species of non-human primates have been exploited as animal disease models for human hantavirus infections. to study the potential risk of natural hantavirus infection of non-human primates, we investigated serum samples from non-human primates of three species living in outdoor enclosures of the german primate center (gpc), göttingen, located in a hantavirus endemic region of central germany. for that purpose we used serological assays based on recombinant antigens of the bank vole (m ...201120727685
comparative analysis by chromosome painting of the sex chromosomes in arvicolid rodents.sex chromosome evolution in mammals has been extensively investigated through chromosome-painting analyses. in some rodent species from the subfamily arvicolinae the sex chromosomes contain remarkable features such as giant size, a consequence of heterochromatic enlargement, or asynaptic behaviour during male meiosis. here, we have made a comparative study of the sex chromosomes in 6 arvicolid species using different probes from the x and y chromosomes of 3 species, in order to gain knowledge ab ...201120689262
phenotypic evolution of dispersal-enhancing traits in insular voles.evolutionary theory predicts that in metapopulations subject to rapid extinction-recolonization dynamics, natural selection should favour evolution of traits that enhance dispersal and recolonization ability. metapopulations of field voles (microtus agrestis) on islands in the stockholm archipelago, sweden, are characterized by frequent local extinction and recolonization of subpopulations. here, we show that voles on the islands were larger and had longer feet than expected for their body size, ...201120685710
further experiments on the field vole with tubercle bacilli. 194120475590
the relative susceptibility of the field-vole to the bovine, human and avian types of tubercle bacilli and to the vole strain of acid-fast bacillus (wells, 1937). 193920475488
chromosomal evolution of arvicolinae (cricetidae, rodentia). iii. karyotype relationships of ten microtus species.the genus microtus consists of 65 extant species, making it one of the rodentia genera with the highest number of species. the extreme karyotype diversification in microtus has made them an ideal species group for comparative cytogenetics and cytotaxonomy. conventional comparative cytogenetic studies in microtus have been based mainly on chromosomal banding patterns; the number of microtus species examined by molecular cytogenetics-cross-species chromosome painting-is limited. in this study, we ...201020379801
field vole (microtus agrestis) seasonal spacing behavior: the effect of predation risk by mustelids.there are numerous studies showing that predation risk may change different aspects of the behavior of prey, such as habitat use, activity pattern, and foraging. prey should exhibit the strongest antipredatory response against their most deadly predator. small mustelids are considered the most important mammalian predators of voles. nevertheless, there is no general agreement as to whether strong antipredatory reactions exist in natural free-living populations of voles. here, we studied the fiel ...201020352179
the effects of landscape modifications on the long-term persistence of animal populations.the effects of landscape modifications on the long-term persistence of wild animal populations is of crucial importance to wildlife managers and conservation biologists, but obtaining experimental evidence using real landscapes is usually impossible. to circumvent this problem we used individual-based models (ibms) of interacting animals in experimental modifications of a real danish landscape. the models incorporate as much as possible of the behaviour and ecology of four species with contrasti ...201020126614
maternal corticosterone but not testosterone level is associated with the ratio of second-to-fourth digit length (2d:4d) in field vole offspring (microtus agrestis).the steroid environment encountered by a foetus can strongly affect its post-natal physiology and behaviour. it has been proposed that steroid concentrations experienced in utero could be estimated from adults by measuring their second-to-fourth digit length ratio (2d:4d). however, there is still little direct evidence that intra-uterine steroid levels affect individual 2d:4d. we examined whether maternal pre-pregnancy testosterone and corticosterone levels (as estimates of intra-uterine testost ...201019958785
characterization of a novel wood mouse virus related to murid herpesvirus 4.two novel gammaherpesviruses were isolated, one from a field vole (microtus agrestis) and the other from wood mice (apodemus sylvaticus). the genome of the latter, designated wood mouse herpesvirus (wmhv), was completely sequenced. wmhv had the same genome structure and predicted gene content as murid herpesvirus 4 (muhv4; murine gammaherpesvirus 68). overall nucleotide sequence identity between wmhv and muhv4 was 85 % and most of the 10 kb region at the left end of the unique region was particu ...201019940063
individual growth rates in natural field vole, microtus agrestis, populations exhibiting cyclic population dynamics.rodents that have multi-annual cycles of density are known to have flexible growth strategies, and the "chitty effect", whereby adults in the high-density phase of the cycle exhibit larger average body mass than during the low phase, is a well-documented feature of cyclic populations. despite this, there have been no studies that have repeatedly monitored individual vole growth over time from all phases of a density cycle, in order to evaluate whether such variation in body size is due to differ ...201019916066
extensive host sharing of central european tula virus.to examine the host association of tula virus (tulv), a hantavirus present in large parts of europe, we investigated a total of 791 rodents representing 469 microtus arvalis and 322 microtus agrestis animals from northeast, northwest, and southeast germany, including geographical regions with sympatric occurrence of both vole species, for the presence of tulv infections. based on serological investigation, reverse transcriptase pcr, and subsequent sequence analysis of partial small (s) and mediu ...201019889769
the celtic fringe of britain: insights from small mammal phylogeography.recent genetic studies have challenged the traditional view that the ancestors of british celtic people spread from central europe during the iron age and have suggested a much earlier origin for them as part of the human recolonization of britain at the end of the last glaciation. here we propose that small mammals provide an analogue to help resolve this controversy. previous studies have shown that common shrews (sorex araneus) with particular chromosomal characteristics and water voles (arvi ...200919793757
physiological models of leptin resistance.in common forms of obesity, animals and humans become leptin resistant associated with impaired regulation of energy homeostasis. over the last decade, significant advances in delineating the underlying mechanisms have been achieved. as well as the obvious scientific progress obtained by novel transgenic animals, natural and physiological models of leptin resistance such as the siberian hamster (phodoups sungorus), the field vole (microtus agrestis) or the rat during pregnancy have also provided ...200919732287
the effects of spatial and temporal heterogeneity on the population dynamics of four animal species in a danish landscape.variation in carrying capacity and population return rates is generally ignored in traditional studies of population dynamics. variation is hard to study in the field because of difficulties controlling the environment in order to obtain statistical replicates, and because of the scale and expense of experimenting on populations. there may also be ethical issues. to circumvent these problems we used detailed simulations of the simultaneous behaviours of interacting animals in an accurate facsimi ...200919549327
mycobacterium microti: more diverse than previously thought.mycobacterium microti is a member of the mycobacterium tuberculosis complex of bacteria. this species was originally identified as a pathogen of small rodents and shrews and was associated with limited diversity and a much reduced spoligotype pattern. more recently, specific deletions of chromosomal dna have been shown to define this group of organisms, which can be identified by the absence of chromosomal region rd1(mic). we describe here the molecular characteristics of 141 strains of the myco ...200919535520
patterns of orthopox virus wild rodent hosts in south germany.although cowpox virus (cpxv) infections in a variety of dead-end hosts have been investigated in germany for more than 50 years, data on species and geographical distribution of cpxv in reservoir hosts are sparse. here we present the first comprehensive study of 825 rodents that have been collected in bavaria, southern germany. in summary, six different rodent species (apodemus flavicollis, myodes glareolus, microtus arvalis, apodemus sylvaticus, microtus agrestis, and arvicola amphibius) were t ...200919492947
predation and fragmentation portrayed in the statistical structure of prey time series.statistical autoregressive analyses of direct and delayed density dependence are widespread in ecological research. the models suggest that changes in ecological factors affecting density dependence, like predation and landscape heterogeneity are directly portrayed in the first and second order autoregressive parameters, and the models are therefore used to decipher complex biological patterns. however, independent tests of model predictions are complicated by the inherent variability of natural ...200919419539
endopolyploidization and the interstitial invasion of the supergiant trophoblast cells of the field vole microtus rossiaemeridionalis.the supergiant trophoblast cells characteristic of vole placenta prove to be highly invasive being found at the boundary of the decidualized endometrium and myometrium. their size (100 microm and higher) suggests them to be highly polyploid, though their ploidy was not determined by now. we performed determination of the ploidy level of the supergiant trophoblast cells (sugt) in order to verify whether the highly polyploid trophoblast cells are capable of deep intrauterine invasion. anti-cytoker ...200919329135
seasonal host dynamics drive the timing of recurrent epidemics in a wildlife population.the seasonality of recurrent epidemics has been largely neglected, especially where patterns are not driven by forces external to the population. here, we use data on cowpox virus in field voles to explore the seasonal patterns in wildlife (variable abundance) populations and compare these with patterns previously found in humans. timing in our system was associated with both the number and the rate of recruitment of susceptible hosts. a plentiful and sustained supply of susceptible hosts throug ...200919203924
host condition and individual risk of cowpox virus infection in natural animal populations: cause or effect?recent studies have provided evidence that endemic pathogens may affect dynamics in animals. however, such studies have not typically considered that infected individuals might have a preceding underlying poor condition. we examined whether individuals in poor condition are more likely to become infected by an endemic pathogen, using as a system the dynamics of cowpox virus in field voles. with data from monthly sampled vole populations, a nested case-control study evaluated whether susceptible ...200919144246
relative importance of ixodes ricinus and ixodes trianguliceps as vectors for anaplasma phagocytophilum and babesia microti in field vole (microtus agrestis) populations.the importance of ixodes ricinus in the transmission of tick-borne pathogens is well recognized in the united kingdom and across europe. however, the role of coexisting ixodes species, such as the widely distributed species ixodes trianguliceps, as alternative vectors for these pathogens has received little attention. this study aimed to assess the relative importance of i. ricinus and i. trianguliceps in the transmission of anaplasma phagocytophilum and babesia microti among united kingdom fiel ...200818820068
azurocytes in wild field voles: factors associated with their occurrence.the occurrence of azurocytes (az), a type of leukocyte unique to voles and previously described for three microtus species, is now reported in microtus agrestis. the goal of this study was to shed new light on the possible function and significance of these cells and on how they play a role in the natural history of rodent species. individuals from three vole populations were sampled monthly for 2 years. a hemogram was produced for each individual, and az counts estimated. the counts of az were ...200818704584
prion protein amino acid determinants of differential susceptibility and molecular feature of prion strains in mice and voles.the bank vole is a rodent susceptible to different prion strains from humans and various animal species. we analyzed the transmission features of different prions in a panel of seven rodent species which showed various degrees of phylogenetic affinity and specific prion protein (prp) sequence divergences in order to investigate the basis of vole susceptibility in comparison to other rodent models. at first, we found a differential susceptibility of bank and field voles compared to c57bl/6 and wo ...200818654630
voles on small islands: effects of food limitation and alien predation.ecosystems of three trophic levels may be bottom-up (by food-plant availability) and/or top-down (by predators) limited. top-down control might be of greater consequence when the predation impact comes from an alien predator. we conducted a replicated two-factor experiment with field voles (microtus agrestis) during 2004-2005 on small islands of the outer archipelago of the baltic sea, south-west finland, manipulating both predation impact by introduced american mink (mustela vison) and winter f ...200818607635
the dynamics of health in wild field vole populations: a haematological perspective.1. pathogens have been proposed as potentially important drivers of population dynamics, but while a few studies have investigated the impact of specific pathogens, the wealth of information provided by general indices of health has hardly been exploited. by evaluating haematological parameters in wild populations, our knowledge of the dynamics of health and infection may be better understood. 2. here, haematological dynamics in natural populations of field voles are investigated to determine en ...200818564292
are silica defences in grasses driving vole population cycles?understanding the factors that drive species population dynamics is fundamental to biology. cyclic populations of microtine rodents have been the most intensively studied to date, yet there remains great uncertainty over the mechanisms determining the dynamics of most of these populations. for one such population, we present preliminary evidence for a novel mechanism by which herbivore-induced reductions in plant quality alter herbivore life-history parameters and subsequent population growth. w ...200818482904
parasite interactions in natural populations: insights from longitudinal data.the physiological and immunological state of an animal can be influenced by current infections and infection history. consequently, both ongoing and previous infections can affect host susceptibility to another parasite, the biology of the subsequent infection (e.g. infection length) and the impact of infection on host morbidity (pathology). in natural populations, most animals will be infected by a succession of different parasites throughout the course of their lives, with probably frequent co ...200818474121
the impact of experimentally elevated energy expenditure on oxidative stress and lifespan in the short-tailed field vole microtus agrestis.life-history theory assumes that animal life histories are a consequence of trade-offs between current activities and future reproductive performance or survival, because resource supply is limited. empirical evidence for such trade-offs in the wild are common, yet investigations of the underlying mechanisms are rare. life-history trade-offs may have both physiological and ecological mediated costs. one hypothesized physiological mechanism is that elevated energy metabolism may increase reactive ...200818467297
poor condition and infection: a vicious circle in natural populations.pathogens may be important for host population dynamics, as they can be a proximate cause of morbidity and mortality. infection dynamics, in turn, may be dependent on the underlying condition of hosts. there is a clear potential for synergy between infection and condition: poor condition predisposes to host infections, which further reduce condition and so on. to provide empirical data that support this notion, we measured haematological indicators of infection (neutrophils and monocytes) and co ...200818448414
a new whipworm from arvicolid rodents, trichuris arvicolae feliu et al., 2000, in the helminth fauna of poland.during the parasitological examination of wild rodents from the vicinity of wrocław a single whipworm female was isolated from a field vole microtus agrestis. the nematode was determined as trichuris arvicolae. this is the first report of this parasite in poland.200718441882
prevalence of toxoplasma gondii in small mammals from the ardennes region, france.serum samples from 218 small mammals trapped in forest and grassland in the ardennes region (north-eastern france) were tested for antibodies to toxoplasma gondii. using the modified agglutination test, positive results were found in 4/92 apodemus sp., 3/64 clethrionomys glareolus, 0/26 microtus agrestis, 0/4 micromys minutus, 3/5 sorex sp., 2/9 arvicola terrestris, and 7/18 talpa europaea. toxoplasma gondii was not isolated from the heart of seropositive individuals after bioassay in mice. sero ...200718303774
consumption of grass endophytes alters the ultraviolet spectrum of vole urine.fungal endophytes of grasses are known to benefit their hosts directly by increasing resistance to herbivores through mycotoxins. we propose and test assumptions of a novel hypothesis according to which fungal endophytes of grasses may benefit their hosts also indirectly by increasing the conspicuousness of a mammalian herbivore, the field vole (microtus agrestis), to its avian predators by enhancing the ultraviolet visibility of vole urine. we found that field voles feeding on endophyte-infecte ...200818274778
cowpox virus infection in natural field vole microtus agrestis populations: significant negative impacts on survival.1. cowpox virus is an endemic virus circulating in populations of wild rodents. it has been implicated as a potential cause of population cycles in field voles microtus agrestis l., in britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. this study tests the hypothesis that wild field voles infected with cowpox virus have a lower probability of survival than uninfected individuals. 2. the effect of cowpox virus infec ...200818177331
sensitivity to assumptions in models of generalist predation on a cyclic prey.ecological theory predicts that generalist predators should damp or suppress long-term periodic fluctuations (cycles) in their prey populations and depress their average densities. however, the magnitude of these impacts is likely to vary depending on the availability of alternative prey species and the nature of ecological mechanisms driving the prey cycles. these multispecies effects can be modeled explicitly if parameterized functions relating prey consumption to prey abundance, and realistic ...200718027760
tuberculosis (mycobacterium microti) in wild field vole populations.vole tuberculosis (tb; mycobacterium microti) is an understudied endemic infection. despite progressing slowly, it causes severe clinical pathology and overt symptoms in its rodent host. tb was monitored for 2 years in wild field voles in kielder forest, uk. the prevalence of characteristic cutaneous tb lesions was monitored longitudinally at 4 sites, with individuals live-trapped and repeatedly monitored. a prevalence of 5.2% of individuals with lesions was recorded (n=2791). in a cross-section ...200818005472
disease effects on reproduction can cause population cycles in seasonal environments.1. recent studies of rodent populations have demonstrated that certain parasites can cause juveniles to delay maturation until the next reproductive season. furthermore, a variety of parasites may share the same host, and evidence is beginning to accumulate showing nonindependent effects of different infections. 2. we investigated the consequences for host population dynamics of a disease-induced period of no reproduction, and a chronic reduction in fecundity following recovery from infection (s ...200818005128
chromosomal evolution of arvicolinae (cricetidae, rodentia). ii. the genome homology of two mole voles (genus ellobius), the field vole and golden hamster revealed by comparative chromosome painting.using cross-species chromosome painting, we have carried out a comprehensive comparison of the karyotypes of two ellobius species with unusual sex determination systems: the transcaucasian mole vole, ellobius lutescens (2n = 17, x in both sexes), and the northern mole vole, ellobius talpinus (2n = 54, xx in both sexes). both ellobius species have highly rearranged karyotypes. the chromosomal paints from the field vole (microtus agrestis) detected, in total, 34 and 32 homologous autosomal regions ...200717924201
chromosomal evolution of arvicolinae (cricetidae, rodentia). i. the genome homology of tundra vole, field vole, mouse and golden hamster revealed by comparative chromosome painting.cross-species chromosome painting has become the mainstay of comparative cytogenetic and chromosome evolution studies. here we have made a set of chromosomal painting probes for the field vole (microtus agrestis) by dop-pcr amplification of flow-sorted chromosomes. together with painting probes of golden hamster (mesocricetus auratus) and mouse (mus musculus), the field vole probes have been hybridized onto the metaphases of the tundra vole (microtus oeconomus). a comparative chromosome map betw ...200717497247
dioxin exposure in contaminated sawmill area: the use of molar teeth and bone of bank vole (clethrionomys glareolus) and field vole (microtus agrestis) as biomarkers.developmental disorders of teeth are among the most sensitive targets of polychlorinated dibenzo-p-dioxin and -furan (pcdd/f) exposure. in rats, 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) reduces dose-dependently the size of molars, most severely the third lower molars. dioxins also have effects on developing bone, including altered bone mineral density as well as reduced bending breaking force and stiffness. the aim of this study was to evaluate the use of the third lower molar and long bones a ...200717335869
regulation of body mass and adiposity in the field vole, microtus agrestis: a model of leptin resistance.adult mammals are typically highly resistant to perturbations in their energy balance. in obese humans, however, this control appears to be lost. apart from a few exceptional cases, this loss of control occurs despite appropriate levels of circulating leptin -- suggesting that elevated adiposity may be a consequence of failure to respond to the leptin signal: leptin resistance. when cold-acclimated male field voles (microtus agrestis) are transferred from short (sd, 8 h light) to long (ld, 16 h ...200717283227
altered expression of socs3 in the hypothalamic arcuate nucleus during seasonal body mass changes in the field vole, microtus agrestis.we have previously shown that cold-acclimated (8 degrees c) male field voles (microtus agrestis) transferred from short day (sd, 8 h light) to long day (ld, 16 h light) photoperiod exhibit an increase in body mass lasting 4 weeks, after which they stabilise at a new plateau approximately 7.5 g (24.8%) higher than animals maintained in sd. by infusing voles with exogenous leptin, we have also demonstrated that sd voles respond to the hormone by reducing body mass and food intake, whereas ld anima ...200717214870
ultradian rhythms and the nutritional importance of caecotrophy in captive brandt's voles (lasiopodomys brandtii).ingestion of soft faeces derived from caecal contents, caecotrophy, in herbivorous small mammals is considered an adaptation to the metabolic disadvantage of small body size, especially when feeding on diets of low quality. we investigated daily activity patterns in captive brandt's voles (lasiopodomys brandtii), including feeding, locomotion, caecotrophy, and defaecation, by continuous 24 h visual observation; and estimated the contribution of soft faeces ingestion (caecotrophy) to intake of pr ...200717211665
sympatric ixodes trianguliceps and ixodes ricinus ticks feeding on field voles (microtus agrestis): potential for increased risk of anaplasma phagocytophilum in the united kingdom?the importance of wild rodents as reservoirs of zoonotic tick-borne pathogens is considered low in the united kingdom because, in studies to date, those parasitized by exophilic ixodes ricinus ticks carry almost exclusively larvae and thus have a minor role in transmission cycles. in a cross-sectional study, 11 (6.7%) of 163 field voles (microtus agrestis) captured at field sites in northern england were pcr-positive for anaplasma phagocytophilum. the voles were found to act as hosts for both la ...200617187576
costs of coexistence along a gradient of competitor densities: an experiment with arvicoline rodents.1. costs of coexistence for species with indirect resource competition usually increase monotonically with competitor numbers. very little is known though about the shape of the cost function for species with direct interference competition. 2. here we report the results of an experiment with two vole species in artificial coexistence in large enclosures, where density of the dominant competitor species (microtus agrestis) was manipulated. experimental populations of the subordinate vole species ...200717184354
contrasting dynamics of bartonella spp. in cyclic field vole populations: the impact of vector and host dynamics.many zoonotic disease agents are transmitted between hosts by arthropod vectors, including fleas, but few empirical studies of host-vector-microparasite dynamics have investigated the relative importance of hosts and vectors. this study investigates the dynamics of 4 closely related bartonella species and their flea vectors in cyclic populations of field voles (microtus agrestis) over 3 years. the probability of flea infestation was positively related to field vole density 12 months previously i ...200717096870
cowpox virus infection in natural field vole microtus agrestis populations: delayed density dependence and individual risk.1. little is known about the dynamics of pathogen (microparasite) infection in wildlife populations, and less still about sources of variation in the risk of infection. here we present the first detailed analysis of such variation. 2. cowpox virus is an endemic sublethal pathogen circulating in populations of wild rodents. cowpox prevalence was monitored longitudinally for 2 years, in populations of field voles exhibiting multiannual cycles of density in kielder forest, uk. 3. the probability th ...200617032374
incomplete sister chromatid separation of long chromosome arms.chromosome segregation ensures the equal partitioning of chromosomes at mitosis. however, long chromosome arms may pose a problem for complete sister chromatid separation. in this paper we report on the analysis of cell division in primary cells from field vole microtus agrestis, a species with 52 chromosomes including two giant sex chromosomes. dual chromosome painting with probes specific for the x and the y chromosomes showed that these long chromosomes are prone to mis-segregate, producing d ...200617021850
intraspecific competition, growth, chemistry, and susceptibility to voles in seedlings of betula pendula.we studied the effects of the intensity of intraspecific competition, as indicated by seedling density, and competitive success within populations, as indicated by seedling size, on the secondary chemistry of the stems of silver birch seedlings and their palatability to field voles. we found that the size of seedlings and their total phenolic concentrations were inversely related to stand density. voles, however, did not discriminate between seedlings grown at the densities studied. variation in ...200617001532
artificial reproduction of the yangtze field vole: in vitro embryo development and fertilization with fresh and freeze-thawed sperm.several research groups are using the yangtze field vole as a model for studying schistosome infection, but relatively little is known about the species's reproductive physiology. the authors examined the vole's in vivo and in vitro embryonic development as well as the efficacy of in vitro fertilization using either fresh or cryopreserved sperm to breed these rodents.200616943792
experimental demonstration of the antiherbivore effects of silica in grasses: impacts on foliage digestibility and vole growth rates.the impact of plant-based factors on the population dynamics of mammalian herbivores has been the subject of much debate in ecology, but the role of antiherbivore defences in grasses has received relatively little attention. silica has been proposed as the primary defence in grasses and is thought to lead to increased abrasiveness of foliage so deterring feeding, as well as reducing foliage digestibility and herbivore performance. however, at present there is little direct experimental evidence ...200616928631
a role for vector-independent transmission in rodent trypanosome infection?within host-pathogen systems where vector-borne transmission is the primary route of infection, little or no attention has been paid to the relative importance of secondary or alternative routes of transmission. here, by contrast, we report the results from a controlled longitudinal field-scale experiment in which the prevalence of fleas (siphonaptera) was manipulated and the occurrence and distribution of a flea-borne protozoan (trypanosoma (herpetosoma) microti) in a natural field vole (microt ...200616876803
diabetes and myocarditis in voles and lemmings at cyclic peak densities--induced by ljungan virus?although it is well-documented from theoretical studies that pathogens have the capacity to generate cycles, the occurrence and role of pathogens and disease have been poorly empirically studied in cyclic voles and lemmings. in screening for the occurrence of disease in cyclic vole and lemming populations, we found that a high proportion of live-trapped clethrionomys glareolus, c. rufocanus, microtus agrestis and lemmus lemmus at high collective peak density, shortly before the decline, suffered ...200616868760
[anoplura of rodents (rodentia) in northern poland].anoplura of rodents (rodentia) in northern poland. above 100 rodents belonging to 6 species (clethrionomys glareolus, microtus agrestis, m. arvalis, apodemus flavicollis, a. sylvaticus, mus musculus) caught in the various habitations were examined. the parasites found represented three species of anoplura: hoplopleura acanthopus, h. affinis and polyplax serrata. h. acanthopus appeard to be the most common parasite; it was found in all examined hosts, while mostly on the bank vole.200416859044
[a study of dna depolyploidization and depolytenization of the heterochromatized gonosomal chromatin bodies in the secondary giant trophoblast cells of the field vole microtus rossiaemeridionalis using cytophotometry].a study was made of the distribution of the heterochromatized gonosomal chromatin bodies (gcb) material in the course of nuclear fragmentation of secondary giant trophoblast cells resulting in polykaryocyte formation at the late stage of their differentiation. a simultaneous dna cytophotometry in gcbs and nuclear fragments showed a progressive gcb dna content decrease proportional to that of dna content in nuclear fragments. dna contents in the nuclear fragments corresponded to 2c, 4c and 8c. in ...200516711385
delayed density-dependent season length alone can lead to rodent population cycles.studies of cyclic microtine populations (voles and lemmings) have suggested a relationship between the previous year's population density and the subsequent timing of the onset of reproduction by overwintered breeding females. no studies have explored the importance of this relationship in the generation of population cycles. here we mathematically examine the implications of variation in reproductive season length caused by delayed density-dependent changes in its start date. we demonstrate tha ...200616671013
changes over time in the spatiotemporal dynamics of cyclic populations of field voles (microtus agrestis l.).we demonstrate changes over time in the spatial and temporal dynamics of an herbivorous small rodent by analyzing time series of population densities obtained at 21 locations on clear cuts within a coniferous forest in britain from 1984 to 2004. changes had taken place in the amplitude, periodicity, and synchrony of cycles and density-dependent feedback on population growth rates. evidence for the presence of a unidirectional traveling wave in rodent abundance was strong near the beginning of th ...200616671000
vole population cycles in northern and southern europe: is there a need for different explanations for single pattern?1. students of population cycles in small rodents in fennoscandia have accumulated support for the predation hypothesis, which states that the gradient in cycle length and amplitude running from southern to northern fennoscandia reflects the relative influence of specialist and generalist predators on vole dynamics, itself modulated by the presence of snow cover. the hypothesized role of snow cover is to isolate linked specialist predators, primarily the least weasel, mustela n. nivalis l. and t ...200616637987
proliferation and apoptosis in early molar morphogenesis-- voles as models in odontogenesis.proliferation and apoptosis play crucial roles in the development of multicellular organisms. their precise balance is necessary for tissue homeostasis throughout life. the developing dentition is a suitable model to study proliferation and apoptosis during embryogenesis, but the corresponding studies have been carried out principally in the mouse. the present study aimed to examine proliferation and apoptosis in the vole (microtus sp., rodentia) during the early morphogenesis of the first upper ...200616586349
toxoplasmosis: a serological survey in ontario wildlife.sera from seven species of wild animals in ontario were examined for antibody to toxoplasma gondii using the sabin-feldman dye test. of 158 sera tested, 53% of the red foxes (vulpes vulpes), 56% of the striped skunks (mephitis mephitis), 78% of the coyotes (canis latrans), 33% of the black bears (ursus americanus), 18% of the short tailed shrews (blarina brevicauda) and none of the field voles (microtus pennsylvanicus) had antibody. antibody to t. gondii was present in sera from wild animals cap ...197616502687
bovine tuberculosis infection in wild mammals in the south-west region of england: a survey of prevalence and a semi-quantitative assessment of the relative risks to cattle.in the united kingdom, badgers are implicated in the transmission of mycobacterium bovis to cattle, but little information is available on the potential role of other wild mammals. this paper presents the results of the largest systematic uk survey of m. bovis infection in other wild mammals. mammal carcasses (4715) from throughout the south-west region of england were subjected to a systematic post mortem examination, microbiological culture of tissues and spoligotyping of isolates. infection w ...200716434219
photoperiod regulates leptin sensitivity in field voles, microtus agrestis.we have previously shown that cold-acclimated (8 degrees c) male field voles (microtus agrestis) transferred from short (sd, 8:16 h l:d) to long photoperiod (ld, 16:8 h l:d) exhibit increases in body mass, adiposity and food intake. to assess whether these increases were associated with decreased leptin sensitivity, we infused ld and sd voles with physiological doses of murine leptin (or saline) delivered peripherally for 7 days via mini-osmotic pumps. measurements were made of body mass (weight ...200616402185
whole-genome chromosome distribution during nuclear fragmentation of giant trophoblast cells of microtus rossiaemeridionalis studied with the use of gonosomal chromatin arrangement.gonosomal chromatin bodies (gcbs), i.e. blocks of condensed chromatin consisting of heterochromatized region of the sex chromosomes of the field vole m. rossiaemeridionalis, were used as a natural interphase chromosome marker in order to clarify the regularities of gcb rearrangement during nuclear fragmentation of secondary giant trophoblast cells (sgtcs) at the end of their differentiation. cytophotometrical measurements of dna content in the nuclei, nuclear fragments and simultaneously in the ...200516314124
trypanosomes, fleas and field voles: ecological dynamics of a host-vector--parasite interaction.to investigate the prevalence of a flea-borne protozoan (trypanosoma (herpetosoma) microti) in its field vole (microtus agrestis) host, we monitored over a 2-year period a range of intrinsic and extrinsic parameters pertaining to host demographics, infection status and vector (flea) prevalence. generalized linear mixed modelling was used to analyse patterns of both flea and trypanosome occurrence. overall, males of all sizes and ages were more likely to be infested with fleas than their female c ...200516178357
relationship between vestibular lamina, dental lamina, and the developing oral vestibule in the upper jaw of the field vole (microtus agrestis, rodentia).formation of the oral vestibule is ignored in most studies on tooth development, although dental and vestibular lamina are closely related to each other. knowledge about morphogenetic processes shaping the oral vestibule is missing almost completely. the aim of this study was to assess the developmental relationship between dental and vestibular lamina as well as formation of the oral vestibule in the upper jaw of the field vole (microtus agrestis), a small rodent representing an attractive mode ...200516025539
comparison of different approaches for the calculation of energy expenditure using doubly labeled water in a small mammal.the doubly labeled water (dlw) method is an isotope-based technique for the estimation of the co(2) production, and hence energy expenditure, of free-living animals and humans. several methods are available for the calculation of co(2) production from the isotope fluxes, depending on different assumptions about the behavior of isotopes during the elimination process. we used the dlw method to estimate the daily energy expenditures (dee) of 55 field voles (microtus agrestis) held in a captive fac ...201315957119
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