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.     

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.     

The use of arboreal runways by the woodland rodents, Apodemus sylvaticus (L.), A. flavicollis (Melchior) and Clethrionomys glareolus (Schreber)

The use of arboreal runways by the rodents, Apodemus sylvaticus, A. flavicollis and Clethrionomys glareolus , was investigated in the deciduous woodland of Woodchester Park, Gloucestershire, England. Longworth live traps were tied to horizontal and inclining branches of trees and shrubs up to 3 m. Arboreality was extensive in all three species, although less in C. glareolus than in either Apodemus species. There was no indication that A. flavicollis consistently used arboreal runways more than A. sylvaticus but the data suggest that the peak of arboreal activity of these congeners occurred in different seasons. In A. sylvaticus , males were more arboreal than females and adults were more arboreal than juveniles. In, 4. flavicollis , juveniles were trapped significantly more often on arboreal runways than adults. The reasons for, and the consequences of, arboreality in small rodents are discussed.     

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.).     

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.     

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.     

Findings of mycobacteria in insectivores and small rodents

The organs of 30 insectivorous mammals and 62 rodents from areas inhabited by people or livestock where cattle paratuberculosis or mycobacterial infections of swine had been found to occur were examined by cultivation during the monitoring of occurrence and spread of mycobacterioses in cattle and swine. Mycobacteria were found in the organs of 3 insectivores (10%) and 6 rodents (9.7%). Mycobacterium chelonae was isolated from the organs of the lesser white-toothed shrew (Crocidura suaveolens) and the common vole (Microtus arvalis), and M. vaccae and M. avium subsp. avium (IS901+, serotype 1) from the organs of the common shrew (Sorex araneus). M. avium subsp. avium (IS901+, serotype 1) was also isolated from the organs of the yellow-necked mouse (Apodemus flavicollis). Slow-growing mycobacteria of group III (according to Runyon) were isolated from the organs of the mouse (Mus musculus sensu lato) and the yellow-necked mouse (A. flavicollis). These findings had no connection with the epizootological situation in the nearby livestock. M. fortuitum was isolated from the organs of the common vole (M. arvalis) caught in a field within easy reach of a swine breeding herd. M. fortuitum was also identified in the lymph nodes and droppings of this swine herd, as well as in the straw, scrapings from the floor of stalls, troughs and banisters, as well as from larvae and imagoes of dipterous insects. These results demonstrate the possibility that insectivores and small rodents can spread the causative agents of mycobacteria in wild and domestic animals.     

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.     

Frenkelia parasites in a small mammal community. Dynamics of infection and effect on the host

A community of small mammals, Clethrionomys glareolus, Arvicola terrestris, Microtus arvalis, M. agrestis, M. subterraneus, Apodemus spp. and Sorex spp., was studied as hosts of Frenkelia glareoli and F. microti in Fronche-Comté (France). They were monitored in spring, summer and autumn on an area of about 1,350 ha comprising open field, hedgerow network and forest. Among 1,714 small mammals examined between July 1992 and October 1993, 47% (178/376) of C. glareolus, 9.9% (14/139) of A. terrestris and 1.3% (4/311) of Apodemus spp. were infected by F. glareoli. The prevalence of infection with F. microti was 9.2% (66/716) in M. arvalis and 8.2% (6/73) in M. agrestis. M. subterraneus and Sorex spp. were not infected. The maintenance of each parasite in a rural landscape is assured both by a forest and a grassland host. Multiple logistic regression showed that prevalence was highly age-dependent, with an apparent seasonal pattern. Prevalence varied between 30% in summer and 60% in early spring for F. glareoli in C. glareolus and between 3% in autumn to 30% in early spring for F. microti in M. arvalis. The year, habitat, host sex, relative density had no impact on prevalence. In M. arvalis only, sexually active voles were preferentially uninfected, indicating a possible impact of this parasitism on fertility.     

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 .     

Preliminary molecular characterization of Cryptosporidium parvum isolates of wildlife rodents from Poland

Isolates of Cryptosporidium were collected from 3 species of woodland and field rodents (Clethrionomys glareolus, Microtus arvalis, and Apodemus flavicollis) and were characterized by polymerase chain reaction amplification and sequencing of fragments of the oocyst wall protein (COWP) gene and of the 18S ribosomal RNA gene. Sequence analysis of these markers revealed that the animals were infected with C. parvum, and that the genotype involved was almost identical to the mouse genotype previously described from Mus musculus. Thus, small rodents should be considered as an important reservoir of C. parvum genotypes closely related to the zoonotic genotype 2 and potentially hazardous to humans.     

Synchrony between small mammal population dynamics in marshes and adjacent grassland in a landscape of the Jura plateau, France: a ten year investigation

Small mammal populations were studied during a 10 year multi-annual fluctuation of vole populations in marshes and adjacent grassland of the basin in the Jura mountains, France. Nine species were monitored:Microtus agrestis, Clethrionomys glareolus, Apodemus flavicollis, Sorex araneus Icoronatus, Neomys fodiens, Crocidura leucodon, Mustela nivalis in marshes andArvicola terrestris andMicrotus arvalis in grassland, using live-trapping and index methods during July from 1993 to 2002. Populations of A.terrestris, M. arvalis, M. agrestis, S. araneus I coronatus andM. nivalis exhibited a relatively strong inter-specific temporal synchrony in their multi-annual fluctuations.C. glareolus population fluctuations were not synchronous to theArvicola I Microtus I Sorex group, and were closer to those ofApodemus flavicollis, Neomys andCrocidura. Those results are discussed in the light of earlier studies carried out in the same region and in northern ecosystems.     

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.     

Studies on the distributions of Apodemus sylvaticus (L.) and A. flavicollis (Melchior) in Britain

The known distributions of A. sylvaticus and A. flavicollis were examined with respect to four woodland classifications and two soil types. The distribution of A. flavicollis in Britain is associated with drier areas and with the distribution of mature, deciduous woodland. A. sylvaticus is found in both wet and dry areas and is distributed independently of deciduous woodland.     

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.     

Use of recombinant vaccinia-rabies glycoprotein virus for oral vaccination of wildlife against rabies: innocuity to several non-target bait consuming species

The pathogenicity of a vaccinia recombinant virus expressing the rabies glycoprotein (VVTGgRAB) was tested in several wild animal species which could compete with the natural rabies host, the red fox (Vulpes vulpes) in consuming vaccine baits in Europe. The following species were included in this study: wild boar (Sus scrofa), Eurasian badger (Meles meles), wood mouse (Apodemus sylvaticus), yellow-necked mouse (Apodemus flavicollis), bank vole (Clethrionomys glareolus), common vole (Microtus arvalis), field vole (Microtus agrestis), water vole (Arvicola terrestris), common buzzard (Buteo buteo), kestrel (Falco tinnunculus), carrion crow (Corvus corone), magpie (Pica pica) and jay (Garrulus glandarius). During the observation period, the 107 animals given the VVTGgRAB vaccine orally did not show any clinical signs. Daily monitoring for 28 days and postmortem examination did not result in the detection of pox lesions in the oral mucosa or the skin in mammals or the unfeathered portions of birds. VVTGgRAB seems to multiply in the mammalian species tested, since rabies seroconversion was observed in all of them. Birds failed to develop demonstrable rabies virus-neutralizing antibody. A seroconversion against vaccinia virus was observed in two of four wild boars. Serological results obtained in badgers and wild boars also demonstrates the absence of direct or indirect horizontal transmission of the recombinant virus. The potential of the recombinant virus for the immunization of badgers against rabies also was investigated. Only 50% of the badgers orally administered with 1 x 10(8.3) TCID50 of this vaccine were protected against rabies.     

Rodent stomach sample preparation for nitrogen NIRS analysis

Near infrared reflectance spectroscopy is a highly promising method for estimating food quality in small mammals. The method used to prepare rodent stomach content samples, however, may influence nitrogenous substance results. In this study, we focus on comparing methods of preparation of samples and finding the optimal preparation method, which means saving time and costs as well as maintenance of reliability and precision of estimation. We examined 1497 stomachs of the following species: Apodemus flavicollis, A. sylvaticus, Clethrionomys glareolus and Microtus arvalis. We used two preparation methods (grinding and abrasion). Where possible, cardiac and pyloric stomach sections were also examined separately. We found no significant difference between these data, hence only financial, time and equipment factors need determine the processing method in future studies.     

Fluctuations in some small rodent populations in Norway 1971–1979

Small rodent populations were monitored by autumn snap trapping in 22 localities of Norway during the years 1971–979. A total of 105528 trap days yielded 7987 small mammals, out of which the bank vole Clethrionomys glareolus and the short-tailed vole Microtus agrestis made up 52.3 and 29.0%, respectively. Third in abundance was the wood mouse Apodemus sylvaticus .
Both M. agrestis and C. glareolus fluctuated fairly regularly, with general peak years of abundance in 1973 and 1977. Other Microtidae, such as M. oeconomus, C. rutilus and Lemmus lemmus apparently also exhibited cyclic fluctuations. In Arvicola terrestris, Apodemus , and in Sorex shrews, regular fluctuations could not be demonstrated, although the abundance varied considerably.
The body weights of sub-adult C. glareolus cycled in accordance with the fluctuations in abundance; the highest weights being recorded in peak years. In M. agrestis , this correlation was less obvious.     

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.