Responses of small mammals to Red fox (Vulpes vulpes) odour

This paper describes the responses of three species of rodents (Apodemus sylvaticus, Microtus agrestis and Clethrionomys glareolus) and a shrew (Sore.x araneus) to traps tainted with the faecal odour of a predator, the Red fox. The rodents generally avoided traps bearing fox odour, but readily entered traps marked with rodent odour, whereas shrews entered all traps equally. Among the rodents, avoidance of fox odour was strongest in male A. sylvaticus and C. glareolus and least in M. agrestis and female A. sylvaticus . Fox droppings were found principally along paths and in open habitats where, of the rodents mentioned, they were most likely to be encountered by A. sylvaticus . It was suggested that avoidance of fox faecal and urinary odours in this species, especially by the active males, would reduce the time spent in areas frequented by foxes, and hence reduce the chance of encountering the predator itself. In contrast, M. agresis would seldom encounter fox droppings in its sub-surface runways, so avoidance of fox faecal odour would do little to reduce its chance of encountering the predator. Avoidance by the rodents of the faecal odour of badger, a predator not present in the study areas, was only slightly less marked than their avoidance of fox faecal odour. It was postulated that similar chemicals eliciting avoidance in rodents may commonly occur in the faeces and urine of carnivores.     

Spatial organization in sympatric populations of Apodemus sylvaticus and A. flavicollis (Rodentia: Muridae)

The spatial organization and relationships of Apodemus sylvaticus and A. flavicollis in mixed deciduous woodland were examined using live-trapping techniques. Each population was aggregated and contagion was greatest during early summer. Aggregation in A sylvaticus varied inversely with density so that at high densities this species was randomly dispersed. In A. flavicollis aggregation increased with increasing density. This interspecific difference may result from differing annual population cycles. Adult males, adult females and juveniles had different patterns of dispersion and association in A. sylvaticus and A. flavicollis suggesting differences in their social behaviour. Intraspecific associations, particularly among males and between males and females, made a major contribution to overall contagion in the populations. A. sylvaticus and A. flavicollis were segregated throughout the year except for late summer and they were also prevalent in different cover types. The behaviour which determined the spatial segregation of the species may be acquired since juvenile A. sylvaticus were associated more frequently with A. flavicollis and juvenile A. flavicollis were associated less frequently with A. sylvaticus than their respective adult conspecifics. Comparing sympatric with allopatric populations of A. sylvaticus , and observing inter-specific behaviour, suggest that the spatial segregation in sympatry results from A. sylvaticus avoiding the competitively superior A. flavicollis .     

Observations of fleas of small mammals at the Gran Paradiso National Park (Italian Occidental Alps)]

The Siphonaptera of small mammals (nearly 200 rodents, insectivora and mustelids) of the Parco Nazionale del Gran Paradiso (Western Italian Alps) have been collected and studied during the years 1973-75. All the animals have been captured at altitudes ranging from 1570 to 2400 m during different seasons. Twelve genera and sixteen species have been identified, namely: Chaetopsylla (C.) homoea homoea from Mustela erminea; Hystrichopsylla (H.) talpae talpae from Clethrionomys glareolus; Rhadinopsylla (A.) integella integella from Clethrionomys glareolus and Microtus nivalis; Ctenophtalmus (C.) agyrtes verbanus from Pitymys multiplex (collected by Beaucournu); Ctenophthalmus (C.) solutus solutus from Apodemus flavicollis and Apodemus sylvaticus; Ctenophthalmus (Medioctenophthalmus) nivalis nivalis from Clethrionomys glareolus, Microtus nivalis and Pitymys multiplex; Doratopsylla dasycnema cuspis from Sorex araneus and Clethrionomys glareolus; Palaeopsylla soricis rosickyi from Sorex araneus; Leptopsylla segnis from Apodemus sylvaticus and Mus musculus; Peromyscopsylla bidentata bidentata from Clethrionomys glareolus and Microtus nivalis; peromyscopsylla fallax from clethrionomgs glareous; Amphipsylla sibirica ssp. from clethrionomys glareolus and microtus nivalis; Malaraeus (Amalaraeus), penicilliger kratachvili from Clethrionomys glareolus, Microtus nivalis and Mustela erminea; Myoxopsylla laverani from Eliomys quercinus; Callopsylla saxatilis from Apodemus flavicollis, Microtus nivalis and Mustela erminea. Species of fleas not yet described in Italy are: Chaetopsylla (C.) homoea homoea; Rhadinopsylla (Actenophthalmus) mesa; Ctenophthalmus (Medioctemophthalmus) nivalis nivalis; Callopsylla saxatilis. The genus Callopsylla is identified for the first time in Italy. New identification of hosts for the species of fleas already described in Italy are: for Rhadinopsylla (Actenophthalmus) integella integella: Clethrionomys glareolus; for Ctenophthalmus (C.) solutus solutus: Apodemus flavicollis and Apodemus sylvaticus. All the 15 male specimens of M. laverani from E. quercinus captured in the Parco Nazionale del Gran Paradiso have characters more similar to M. l. traubi than to M. l. laverani: only one long and a much shorter spine in the superior half of the movable process, a distinct tooth in the anterior margin of the movable half of the movable process, a distinct tooth in the anterior margin of the movable process, crochets of phallosome shorter and more gradually tapered, apex of fixed process very acuminated. To the contrary the shape of the movable process is similar to that of M. l. laverani. A point of particular interest is to be found also in 2 specimens of Amphypsilla of the sibirica group, respectively collected from Mustela erminea and Microtus nivalis. They have a very atypical distribution of the spine in an abnormally shaped movable process: the reasons of the abnormality are due to castration, probably of parasitic origin (absence of phallosome, tendons, etc.).     

The importance of Laelaps agilis C.L. Koch 1836 (Mesostigmata: Parasitiformae) as a vector of Hepatozoon sylvatici Coles 1914 (Sporozoa: Haemogregarinidae) (author's transl)]

The importance of the mite Laelaps agilis (Parasitiformae) for the transmission of the Hepatozoon species living in the blood of Apodemus sylvaticus and Apodemus flavicollis (Hepatozoon sylvatici) is examined. With this mite the experimental transfer of the parasite to bred hosts of the same species was successful five times; for once, the transmission to a non-specific host (Clethrionomys glareolus) was also possible. Besides, an eventual stimulating effect emanating from the gonads of female mites to the development of parasites can be considered. Differences in the morphology of schizonts in the bone marrow and in the liver of infected Apodemus flavicollis are especially pointed out.     

Experimental adiaspiromycosis of the common vole (Microtus arvalis) and other small wild mammals after intraperitoneal inoculation

After intraperitoneal inoculation ofE. crescens to nine species of wild small mammals, six species of rodents (Apodemus flavicollis, A. sylvaticus, Clethrionomys glareolus, Microtus agrestis, M. arvalis, Mus musculus) developed generalized adiaspiromycosis. The course of experimental infection corresponded to the infections of laboratory animals provoked in the same manner of inoculation. The authors studied the affliction of individual organs, the dynamics of growth of adiaspores in the organs of the abdominal cavity and in the lungs and followed up morphological changes in the adiaspores. In fresh cover glass preparations, the presence of manifestations was demonstrated justifying considerations on the capacity of multiplication of the adiaspiromycosis agent in the host organism.     

Differences in the ecology of Bartonella infections of Apodemus flavicollis and Myodes glareolus in a boreal forest

The epidemiology of Bartonella species infecting Apodemus flavicollis and Myodes glareolus in a forest in Eastern Poland was followed for 2 years using mark-recapture. Infections could be acquired in any month, but prevalence, and probability of infection, peaked in the summer. There were significant differences in the pattern of infections between the two species. Both hosts were primarily infected as juveniles, but the probability of infection was highest for A. flavicollis, which, evidence suggests, experienced longer-lasting infections with a wider range of Bartonella genotypes. There was no evidence of increased host mortality associated with Bartonella, although the infection did affect the probability of recapture. Animals could become re-infected, generally by different Bartonella genotypes. Several longer lasting, poorly resolved infections of A. flavicollis involved more than 1 genotype, and may have resulted from sequential infections. Of 22 Bartonella gltA genotypes collected, only 2 (both B. grahamii) were shared between mice and voles; all others were specific either to A. flavicollis or to M. glareolus, and had their nearest relatives infecting Microtus species in neighbouring fields. This heterogeneity in the patterns of Bartonella infections in wild rodents emphasizes the need to consider variation between both, host species and Bartonella genotypes in ecological and epidemiological studies.     

Molecular detection of Bartonella species infecting rodents in Slovenia

Rodents, collected in three zoogeographical regions across Slovenia, were tested for the presence of bartonellae using direct PCR-based amplification of 16S/23S rRNA gene intergenic spacer region (ITS) fragments from splenic DNA extracts. Bartonella DNA was detected in four species of rodents, Apodemus flavicollis, Apodemus sylvaticus, Apodemus agrarius and Clethrionomys glareolus, in all three zoogeographic regions at an overall prevalence of 40.4%. The prevalence of infection varied significantly between rodent species and zoogeographical regions. Comparison of ITS sequences obtained from bartonellae revealed six sequence variants. Four of these matched the ITS sequences of the previously recognized species, Bartonella taylorii, Bartonella grahamii, Bartonella doshiae and Bartonella birtlesii, but one was new. The identity of the bartonellae from which the novel ITS sequences was obtained were further assessed by sequence analysis of cell division protein-encoding gene (ftsZ) fragments. This analysis demonstrated that the strain is most likely a representative of possible new species within the genus.     

Isolation of Emmonsia crescens Emmons et Jellison 1960 from small mammals in Bulgaria

Authors examined a total of 3849 specimens of mammals included in 36 species from different region of Bulgaria. Adiaspiromycosis was detected microscopically in 18 mammals species. Strains of Emmonsia crescens Emmons et Jellison 1960 was isolated from 6 species--Apodemus flavicollis, Apodemus sylvaticus, Clethrionomys glareolus, Microtus arvalis, Musmusculus and Rattus norvegicus.     

Genetic and morphological heterogeneity in small rodent whipworms in southwestern Europe: characterization of Trichuris muris and description of Trichuris arvicolae n. sp. (Nematoda: Trichuridae)

Genetic and morphological variability of whipworms Trichuris Roederer, 1761 (Nematoda: Trichuridae), parasites of small rodents in southwestern Europe, was studied. Isozyme patterns of natural populations of nematodes parasitizing rodent species of the Muridae (Apodemus sylvaticus, Apodemus flavicollis, Mus musculus) and Arvicolidae (Clethrionomys glareolus, Microtus agrestis, Microtus arvalis) were analyzed at 6 putative loci. Two diagnostic loci were found in T. muris from Muridae and from Arvicolidae. Thus, the existence of 2 species of Trichuris restricted to different host families was indicated. They included Trichuris muris Schrank, 1788, originally described as being from mice, and Trichuris arvicolae n. sp., parasitizing the above species of Arvicolidae. The morphological variability of both species was compared. Although ranges of all morphological characters of the new species overlapped with those of T. muris, stepwise discriminant analysis yielded a 100% accurate classification of females when using vagina length and egg size. Males of T. muris and T. arvicolae cannot be separated entirely. A set of 6 variables yielded 95.7% discrimination; the most discriminating variables were spicule size and body width.     

Age-dependent flea (Siphonaptera) parasitism in rodents: a host's life history matters

We studied age-dependent patterns of flea infestation in 7 species of rodents from Slovakia (Apodemus agrarius, A. flavicollis, A. sylvaticus, A. uralensis, Clethrionomys glareolus, Microtus arvalis, and M. subterraneus). We estimated the age of the host from its body mass and expected the host age-dependent pattern of flea abundance, the level of aggregation, and prevalence to be in agreement with theoretical predictions. We expected that the mean abundance and the level of aggregation of fleas would be lowest in hosts of smallest and largest size classes and highest in hosts of medium size classes, whereas pattern of variation of prevalence with host age would be either convex or asymptotic. In general, mean abundance and species richness of fleas increased with an increase in host age, although the pressure of flea parasitism in terms of number of fleas per unit host body surface decreased with host age. We found 2 clear patterns of the change in flea aggregation and prevalence with host age. The first pattern demonstrated a peak of flea aggregation and a trough of flea prevalence in animals of middle age classes (Apodemus species and C. glareolus). The second pattern was an increase of both flea aggregation and flea prevalence with host age (both Microtus species). Consequently, we did not find unequivocal evidence for the main role of either parasite-induced host mortality or acquired resistance in host age-dependent pattern of flea parasitism. Our results suggest that this pattern can be generated by various processes and is strongly affected by natural history parameters of a host species such as dispersal pattern, spatial distribution, and structure of shelters.     

Molecular phylogeny and distribution of three Apodemus species (Muridae, Rodentia) in Serbia

Phylogenetic relationships among three species of the genus Apodemus ( A. flavicollis, A. sylvaticus and A. agrarius ) from seven different localities in Serbia were estimated using arbitrarily primed PCR (AP-PCR) profiling, which allowed clear distinction between the sibling species A. flavicollis and A. sylvaticus . Eight oligonucleotide primers out of the 22 screened, gained a total of 397 amplified bands. The average pairwise genetic distances within Apodemus species ranged from 0.51 between A. flavicollis and A. sylvaticus , to 0.74 between A. sylvaticus and A. agrarius. The large genetic distances obtained among populations of A. flavicollis (0.13) indicate that this part of the Balkan Peninsula was probably a refuge during the last glaciation. Furthermore, differences obtained between populations south and north from the river Danube suggest that this species survived the Last Glacial Maximum in at least two separate refuges. Although our data for molecular markers are from a limited number of localities, extended analyses of C-band distribution on chromosomes from previously studied localities south of the rivers Danube and Sava, indicate that distribution of A. sylvaticus is limited to northern Serbia. Therefore, it is possible that this part of the Balkan Peninsula was not a refuge for this species during the last glaciation.     

Population structure and dynamics of sympatric Apodemus species (Rodentia: Muridae)

This paper describes the population biology of sympatric populations of Apodemus sylvaticus and A. flavicollis in western England. Annual changes in population siie closely resembled those seen in allopatric populations such that simultaneous peaks in number occurred only in autumn and early winter. Numbers of A. sylvaticus were low and stable in early summer increasing rapidly in late summer and autumn and remaining high throughout winter before a sharp decline in spring. Numbers of A. flavicollis increased after the start of reproduction and continued to rise throughout summer and autumn. The period of major decline of this species was during early winter. Densities of A. sylvaticus and A. flavicollis were comparable with those cited in allopatric studies. Spring populations of both species consisted of cohorts first appearing in the late summer and autumn of the previous year. Few individuals present in spring survived the summer. Reproduction of A. flavicollis commenced four to six weeks before that of A. sylvaticus . Seasonal variation in mean weight of adult males and females also indicates that those changes, due to the acquisition of secondary sex characteristics and reproductive maturity, occur earlier in A. flavicollis than in A. sylvaticus . Data presented contain no evidence of interspecific competition and it is concluded that interspecific differences, chiefly asynchrony in reproduction and annual population cycles, contribute to their stable coexistence.     

So close and so different: comparative phylogeography of two small mammal species, the yellow-necked fieldmouse (Apodemus flavicollis) and the woodmouse (Apodemus sylvaticus) in the Western Palearctic region

In Europe, concordant geographical distribution among genetic lineages within different species is rare, which suggests distinct reactions to Quaternary ice ages. This study aims to determine whether such a discrepancy also affects a pair of sympatric species, which are morphologically and taxonomically closely related but which have slight differences in their ecological habits. The phylogeographic structures of two European rodents, the Yellow-necked fieldmouse (A. flavicollis) and the woodmouse (Apodemus sylvaticus) were, therefore, compared on the basis of mitochondrial DNA cytochrome b (mtDNA cyt b) sequences (965 base pairs) from 196 specimens collected from 59 European localities spread throughout the species distributions. The results indicate that the two species survived in different ways through the Quaternary glaciations. A. sylvaticus survived in the Iberian Peninsula from where it recolonized almost all Europe at the end of the last glaciation. Conversely, the refuge from which A. flavicollis recolonized Europe, including northern Spain, during the Holocene corresponds to the Italo-Balkan area, where A. sylvaticus suffered a serious genetic bottleneck. This study confirms that even closely related species may have highly different phylogeographic histories and shows the importance of ecological plasticity of the species for their survival through climate change. Finally, it suggests that phylogeographic distinctiveness may be a general feature of European species.     

Emmonsiosis of wild rodents and insectivores in Czechland

Adiaspores of the fungus Emmonsia crescens were detected microscopically in the lung tissue of 13% of 10.081 small mammals belonging to 24 species examined in 14 areas of the Czech Republic between 1986 and 1997; 441/1.934 (23%) Clethrionomys glareolus, 1/6 (17%) Arvicola terrestris, 357/2.172 (16%) Apodemus flavicollis, 220/1.981 (11%). A sylvaticus, 23/265 (9%) A. microps, 11/81 (14%) Microtus subterraneus, 93/1.275 (7%) M. arvalis, 98/1.439 (7%) M. agrestis, 1/3 (33%) Ondatra zibethicus, 1/1 Cricetus cricetus, 1/20 (5%) Crocidura suaveolens, 2/40 (5%) Neomys fodiens, and 13/529 (2%) Sorex araneus were infected. Emmonsiosis was not recorded among the species of rodents that do not build their nests in the soil (Muscardinus avellanarius, Micromys minutus, Mus musculus, Rattus norvegicus). The overall prevalence of emmonsiosis was significantly higher in adult (19%) than in juvenile (7%) mammals, and in rodents (13%, and 20% in adults) than in insectivores (2%, and 4% in adults). The frequency of infected mammals also varied according to geographic area, altitude, habitat, and season.     

Seasonal and annual variations in the prevalence of blood parasites in cyclic species of small rodents in Norway with special reference to Clethrionomys glareolus

An investigation of the blood parasites of Clethrionomys glareolus, Microtus agrestis and Apodemus sylvaticus from southern Norway revealed four genera, Trypanosoma, Babesia, Hepatozoon and Grahamella. C. glareolus and M. agrestis harbored all four genera, but Hepatozoon was not detected in A. sylvaticus. Babesia was fairly common in M. agrestis but rare in the other rodents. The peak prevalence of Grahamella and Hepatozoon in C. glareolus occurred in early summer whereas trypanosomes peaked near the end of the summer. Infections with trypanosomes and/or Grahamella in C. glareolus were associated with lowered hematocrit levels and enlarged spleens.     

Consistencies in post-dispersal seed predation of temperate fleshy-fruited species among seasons, years and sites

1. Seed predation of 12 fleshy-fruited species was recorded in experimental dishes under early successional forest in south-west Germany (four seasons 1992 and 1993) and in south England (summer 1995). On each occasion, 200 dishes were laid out, each containing five seeds of a given species. The mean time for three or more seeds to be removed was taken as a measure of granivore preferences. We tested correlations of these preferences with several physical and nutritional seed traits.
2. Live trapping and selectively accessible dishes indicated that rodents were the major granivores ( Apodemus sylvaticus, Apodemus flavicollis, Clethrionomys glareolus ); no predation by birds or insects was observed. The rank order of the rodents' seed preferences was consistent among sites, seasons and years, but mean predation differed between species, sites and seasons. Seed predation was highest in summer and lowest in winter. Possible implications of the seasonal pattern in predation risk are discussed.
3. The preferences of rodents were significantly correlated with the species-specific viability of seeds (i.e. percentage of sound seed) in five of eight experiments and with the percentage of water in the embryo-plus-endosperm fraction (EEF) in four of eight experiments. Surprisingly, preferences were not correlated to seed mass, EEF mass or nitrogen concentration. Predation was lowest among toxic species ( Berberis vulgaris, Euonymus europaeus, Sambucus nigra ) and among species with woody endocarps ( Cornus sanguinea, Crataegus spp.).     

Hantaviruses in small wild living mammals in Czechoslovakia. Results of a 1983-1989 study

During a 7- year period were hunted small wild living mammals and examined by ELISA and RIA techniques for the presence of hantavirus antigen and/or antibodies by MFA. In total 3,050 animals of 16 species caught in 9 out of 10 regions of Czechoslovakia, were examined. The proportion of positive animals was 4.4%. To the positive ones with the serotype 2 (Western type) belonged the following: M. arvalis, C. glareolus, P. subterraneus, A. sylvaticus, A. flavicollis. To the Eastern serotype: A. agrarius in eastern Slovakia, A. flavicollis in North of Bohemia and A. sylvaticus in South of Moravia. The repeatedly examined localities were found to be either repeatedly positive or repeatedly negative. The antigen titres in the lungs of M. arvalis were constant irrespective of sex and season of capture. They were, however, much higher in young animals, whereas the proportion of positivities was higher in adults ones. The titres of antigen in the lungs of C. glareolus never exceeded those of M. arvalis.     

Tick-borne zoonotic bacteria in wild and domestic small mammals in northern Spain

The prevalence and diversity of tick-borne zoonotic bacteria (Borrelia spp., Anaplasma phagocytophilum, Coxiella burnetii, and spotted fever group rickettsiae) infecting 253 small mammals captured in the Basque Country (Spain) were assessed using PCR and reverse line blot hybridization. Trapping sites were selected around sheep farms (study 1, 2000 to 2002) and recreational parks (study 2, 2003 to 2005). The majority of the studied mammals (162) were wood mice (Apodemus sylvaticus), but six other different species were also analyzed: yellow-necked mice (Apodemus flavicollis), shrews (Crocidura russula and Sorex coronatus), bank voles (Clethrionomys glareolus), domestic mice (Mus domesticus), and moles (Talpa europaea). The results showed an infection rate ranging from 10.7% to 68.8%, depending on the small mammal species. One C. russula shrew and one A. sylvaticus mouse gave positive reactions for A. phagocytophilum, and C. burnetii was detected in two domestic mice and one A. sylvaticus mouse in a farm. The DNA of Borrelia spp. was detected in 67 animals (26.5%), most of them presenting positive hybridization with the probe for Borrelia sp. strain R57, the new Borrelia species previously detected in small mammals in our region. Furthermore, a second PCR and reverse line blot hybridization specific for B. burgdorferi sensu lato revealed the presence of Borrelia afzelii in 6.3% of C. glareolus voles and 14.3% of S. coronatus shrews. All small mammals were negative for spotted fever group rickettsiae. These results highlight the relevance of small mammals as reservoirs of some zoonotic bacteria.     

Absence of spermatozoal CD46 protein expression and associated rapid acrosome reaction rate in striped field mice (Apodemus agrarius)

Background  

In rodents, the cell surface complement regulatory protein CD46 is expressed solely on the spermatozoal acrosome membrane. Ablation of the CD46 gene is associated with a faster acrosome reaction. Sperm from Apodemus flavicollis (yellow-necked field mice), A. microps (pygmy field mice) and A. sylvaticus (European wood mice) fail to express CD46 protein and exhibit a more rapid acrosome reaction rate than Mus (house mice) or BALB/c mice. A. agrarius (striped field mice) belong to a different Apodemus subgenus and have pronounced promiscuity and large relative testis size. The aim of this study was to determine whether A. agrarius sperm fail to express CD46 protein and, if so, whether A. agrarius have a faster acrosome reaction than Mus.     

The mammalian model for population studies of B chromosomes: the wood mouse (Apodemus)

The presence of B chromosomes was reported in six species of the genus Apodemus (A. peninsulae, A. agrarius, A. sylvaticus, A. flavicollis, A. mystacinus, A. argenteus). High frequencies of Bs were recorded particularly in A. peninsulae and A. flavicollis. The origin of Bs in Apodemus seems to be rather ancient, and it is possible that the supernumerary elements, and/or a tendency for their appearance, were inherited from the common ancestor of the extant species. We have not found any correlated changes between frequencies of Bs and the level of protein polymorphism and/or heterozygosity assessed in electrophoretic studies. No measurable effect of Bs on overall genetic variability was thus revealed in studied populations. The pattern of evolutionary dynamics of Bs can be distinctly different between geographical populations, and both the parasitic and the heterotic models can be applied to explain the maintenance of Bs in different populations. Further studies are desirable to improve our understanding of the complicated evolutionary dynamics of Bs in the Apodemus species. An essential condition for success in this respect is much more detailed information on inheritance and the molecular structure of Bs.