Apodemus Uralensis Research Articles

Wheat or barley?: Feeding preferences affect distribution of three rodent species in agricultural landscape

Spatial distribution of voles and mice and their abundances in agricultural landscape are largely influenced by their food preferences and the distribution of preferred crops. Here we examined the correspondence between food preferences of dominant rodent species (two mice and one vole) for two cereals (wheat and barley) estimated in the lab and the long-term field abundances observed at the harvest time in southern Moravia, Czech Republic. In the first laboratory trial, harvested culms of wheat and barley were offered. The pygmy field mouse preferred (100%) the seed head of wheat, also the wood mouse (87%) and common vole (60%) showed low preference for wheat. In the second trial, we observed similar preferences in consuming the offered grains of both cereals, the wheat being preferred by the pygmy field mouse, and the wood mouse, while with the common vole showing no preference. Laboratory analysis of the harvested grains indicated a lower fibre content in wheat compared with barley. In the field, rodent abundances in wheat were higher than those in barley, especially in mice. This suggests that food preferences in the laboratory correspond closely to field distribution of these rodents and their abundances. Therefore, studying diet preferences may be of essential in predicting small rodent abundances in changing agricultural landscape.

Simple epidemiological model predicts the relationships between prevalence and abundance in ixodid ticks

We tested whether the prevalence of ticks can be predicted reliably from a simple epidemiological model that takes into account only mean abundance and its variance. We used data on the abundance and distribution of larvae and nymphs of 2 ixodid ticks parasitic on small mammals (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Clethrionomys glareolus and Microtus arvalis) in central Europe. Ixodes trianguliceps is active all year round, occurs in the study area in the mountain and sub-mountain habitats only and inhabits mainly host burrows and nests, whereas Ixodes ricinus occurs mainly during the warmer seasons, occupies a large variety of habitats and quests for hosts outside their shelters. In I. ricinus, the models with k values calculated from Taylor's power law overestimated prevalences. However, if moment estimates of k corrected for host number were used instead, expected prevalences of both larvae and nymphs I. ricinus in either host did not differ significantly from observed prevalences. In contrast, prevalences of larvae and nymphs of I. trianguliceps predicted by models using parameters of Taylor's power law did not differ significantly from observed prevalences, whereas the models with moment estimates of k corrected for host number in some cases under-estimated relatively lower larval prevalences and over-estimated relatively higher larval prevalences, but predicted nymphal prevalences well.

Diversity of Small Mammals in Winter Season in North East Lithuania

The trapping of small mammals was done in two winter seasons (2004/2005 and 2005/2006) in the Zarasai district, north-east Lithuania. Nine small mammal species were registered. For Apodemus uralensis, it was the first finding of the species in north-east Lithuania. C. glareolus (49.4% of all trapped animals) were dominating in both seasons both by numbers and by frequency of occurrence. The shares of M. oeconomus, A. uralensis, A. agrarius and M. musculus were less than 1% each. One to six small mammal species were registered every month. Towards spring numbers of trapped C. glareolus decreased; in March–April dominant became M. arvalis. The dominance of C. glareolus was lessening towards spring, when it was changed by M. arvalis. The diversity of the small mammal community in the winter period was not high (averaged Shannon's H = 1.27). Negative correlation (r = -0.64) was found between the number of trapped animals per session (100 traps) and snow depth. M. arvalis was registered breeding quite early: f...

Facultative promiscuity in a presumably monogamous mouseApodemus microps

Promiscuity and monogamy are two extremes of fitness optimisation. Direct evidence for both extremes is documented in numerous studies where a measure of promiscuity/monogamy is often the number of fathers in individual litters using, for example, fragment analysis of highly polymorphic microsatellite loci. In this study, five known polymorphic microsatellite loci were used to assess biological parentage of 174 embryos of 24 pregnant females from a natural Czech population of pygmy field-miceApodemus microps Kratochvil et Rosický, 1952. The results revealed that the majority (67%) of litters were fathered by single males. However, there was a trend showing that the number of males successively (but not significantly) increased during the season, thus suggesting that monogamy in the pygmy field mouse is not obligatory but may depend on a population density and habitat type.

Importance of winter rape for small rodents

Winter rape stands are important habitat for the common vole (Microtus arvalis) and the pygmy field mouse (Apodemus microps). In autumn, the common vole is dominant in this habitat (D = 75%) and reproduces in it (17% of population). This species also dominates the small mammal community of winter rape in early spring (D = 87%), and its reproduction begins in this habitat early; under suitable meteorological conditions 44% of the population of common vole reproduce in March. Analyses of the spring and autumn diet of M. arvalis in winter rape have shown that green leaves of this species form the dominant component of its diet. During the period when the rape crop is ripening, the population abundance of the common vole decreases as green food at ground level decreases. The pygmy field mouse (A. microps) has a contrasting response to winter rape, and it is almost absent from the rape crop from autumn to late spring. However, when winter rapeseeds begun to ripen, the pygmy field mouse concentration in this habitat is in large numbers (dominance D = 76%) and rapeseeds dominate its diet (v% = 72). After the harvest of winter rape, when shed seeds begin to grow, both small mammal species live for some weeks on rape plots.

Phenogenetic Analysis of Pygmy Wood Mouse (Apodemus uralensis Pall.) Populations in the Zone of the Eastern Ural Radioactive Trace (EURT)

Monitoring of A. uralensis populations in Kamenskii raion, Sverdlovsk oblast, in 1992–2002 and in Kaslinskii raion, Chelyabinsk oblast, in 2000–2001 revealed an increase in the proportion and diversity of minor morphogenetic aberrations and abnormalities in the structure of the cranium along the axis of the Eastern Ural Radioactive Trace (EURT). The samples from the southern and northern parts of the EURT (contaminated with 90Sr to 500 and 4 Ci/km2, respectively) were characterized by directed deviations from the control with respect to the frequencies of phenes of nonmetric cranial traits and an increase in the level of their fluctuating asymmetry in young females, which is indicative of epigenetic rearrangements in populations living in a radioactive environment.

Conditional allogrooming in the herb-field mouse

Among members of the family Muridae, the herb-field mouse, Apodemus microps, is unique in that aggression is almost entirely lacking. This species, therefore, is a model organism for experimental studies of social behavior without the confounding influence of aggression. We used video surveillance cameras to assess the importance of self-grooming and allogrooming in the social life of this species. Detailed analysis of individual behavioral sequences using Markov chain methods revealed that self-grooming is a relatively stereotypic, sex-independent activity usually lasting about 8 s. Allogrooming is conditional in the herb-field mouse, because it takes the form of a reciprocal strategy, with the differences between nonmatching bouts varying according to whether the initiator of allogrooming is male or female and whether both interactants are of the same or opposite sex. Our analysis revealed that the exchange of allogrooming bouts between individuals of the same sex is reciprocal, but that males allow females to “defect” more often than vice versa, and males groomed females for longer than predicted by the distribution of individual self-grooming bouts. In those species where the demand for mating by males is far greater than that offered by females, in other words where females may select mates, asymmetry of allogrooming may provide a mechanism for females to test the “suitability” of males for mating. It may also provide the means for males to stimulate females before mating. Furthermore, allogrooming was the only sex-dependent behavior of the several tested in our experiment. As such, we suggest that allogrooming is the predominant premating mechanism in this species.

New Data on the Pygmy Field Mouse (Apodemus Uralensis) Distribution and Habitats in Lithuania

Pygmy field mouse (Apodemus uralensis) was identified as a new mammal species in Lithuania only in 1999. Despite that, many new localities of this species were discovered in northwestern and western Lithuania during 1999–2000: in Žemaitija National Park, Kurtuvėnai and Varniai regional parks, Kamanos strict nature reserve and almost on all the territory of Mažeikiai administrative district. A total of 62 individuals of A. uralensis were captured in 33 localities in 1996–2000. The collected data on A. uralensis dwelling places prove that it is an ‘ecotonic’ species most often residing on the edges of forests and in open habitats bordering on forests. The greatest number of these mice were captured in the ecotones of forests and open habitats (meadows, cornfields and fallow fields) and in open habitats bordering on forests or situated close to them (natural meadows overgrown with shrubs, grass-covered reclamation canals, cornfields). Rather few mice of this species were captured in forests, most often close...

DISCRIMINANT ANALYSIS OF MORPHOMETRIC CHARACTERS IN FOUR SPECIES OF APODEMUS (MURIDAE: RODENTIA) FROM EASTERN TURKEY AND IRAN

We studied 122 wood mice of the subgenus Sylvaemus that were collected from seven localities in Iran (the Zagros Mts. and the Caspian region), seven localities in eastern Turkey, and one locality in Armenia. After capture, mice were kept in captivity until reaching their adult size. The following species were determined using allozyme electrophoresis: Apodemus uralensis (= microps), A. arianus (= hermonensis), A. flavicollis, and a distinct form reported provisionally as A. cf. hyrcanicus. Body weight, four external measurements, and 22 dental and skull measurements were subjected to Discriminant Function Analysis in order to find morphometric criteria allowing species identification. Although there was a close similarity among studied species, 96%, 95%, and 95% of individuals were classified correctly when original measurements, log-transformed data, and residuals of the regression on condylobasal length (“size-out” procedure) were used, respectively. While A. uralensis, A. cf. hyrcanicus, and A. arianus...

Diversity of Small Mammals in the Northwestern Lithuania (Mažeikiai District)

During the investigation carried out in 1997 and 2000 on the territory of Mažeikiai district small mammals representing 13 species were found. The most widespread and abundant were Sorex araneus and Clethrionomys glareolus, captured in all the 20 investigated UTM squares. In more than half of the investigated squares Apodemus agrarius, A. flavicollis, A. uralensis, Microtus arvalis and M. agrestis were detected. Sorex minutes, Neomys fodiens, Mus musculus, Micromys minutes, Microtus oeconomus and M. rossiaemeridionalis were comparatively rare and were captured in less than half of the investigated squares. Rarity of some of the species during the investigation could have been related to their natural fluctuation in abundance. Noteworthy is the wide distribution of Apodemus uralensis quite a recently identified species in Lithuania - on the territory of Mažeikiai district.

Intraspecific behavioural interactions in Apodemus microps : a peaceful mouse?

Social interactions of captive Apodemus microps Kratochvil et Rosicky, 1952 were studied in dyadic encounters.

Sequential meiotic prophase development in the pubertal Indian pygmy field mouse: Synaptic progression of the XY chromosomes, autosomal heterochromatin, and pericentric inversions

Sequential meiotic prophase development has been followed in the pubertal male pygmy mouse Mus terricolor, with the objective to identify early meiotic prophase stages. The pygmy mouse differs from the common mouse by having large heterochromatic blocks in the X and Y chromosomes. These mice also show various chromosomal mutations; for example, fixed variations of autosomal short arms heterochromatin among different chromosomal species and pericentric inversion polymorphism. Identification of prophase stages was crucial to analyzing effects of heterozygosity for these chromosomal changes on the process of homologous synapsis. Here we describe identification of the prophase stages in M. terricolor, especially the pachytene substages, on the basis of morphology of the XY bivalent. Based on this substaging, we show delayed pairing of the heterochromatic short arms, which may be the reason for their lack of chiasmata. The identification of precise pachytene substages also reveals an early occurrence of "synaptic adjustment" in the pericentric inversion heterobivalents, a mechanism that would prevent chiasma formation in the inverted segment and thereby would abate adverse effects of such heterozygosity. The identification of pachytene substages would serve as the basis to analyze the nature of synaptic anomalies met in M. terricolor hybrids (which will be the basis of a subsequent paper).

Sequential meiotic prophase development in the pubertal Indian pygmy field mouse: Synaptic progression of the XY chromosomes, autosomal heterochromatin, and pericentric inversions

Sequential meiotic prophase development in the pubertal Indian pygmy field mouse: Synaptic progression of the XY chromosomes, autosomal heterochromatin, and pericentric inversions

Dynamic of nucleolus organizer regions and karyotype evolution in Indian pygmy field mice

Ag-NOR staining and fluorescence in situ hybridization with rDNA probes showed an unusually high number of NORs in the Indian pygmy field mice, Mus booduga and the M. terricolor complex. The chromosomal location of the NORs was also altered in terricolor, they were shifted from the proximal regions of the long arms to the tips of the perceptible heterochromatic short arms of the acrocentric autosomes. The results suggested dispersion of the NORs in the booduga-terricolor lineage probably by transposition, and relocalization of the NORs in the terricolor complex by centric reorganization during the process of replacement of the Mus musculus-related AT-rich heterochromatin with the terricolor-specific heterochromatin.

Pygmy Field Mouse (Apodemus Uralensis Pallas): A New Mammal Species in Lithuania

Pygmy Field Mouse (<i>Apodemus Uralensis</i> Pallas): A New Mammal Species in Lithuania

High levels of genetic variation in Indian field and house mice

Genetic variation in the Indian pygmy field miceMus booduga and theMus terricolor complex and in the house mouseMus musculus tytleri was analysed electro phoretically at 20 enzymatic and nonenzymatic protein loci. The results show an unusually high genetic variation in the field mice in terms of per cent polymorphism (P = 75 to 90 at 0-95 level), observed heterozygosity (Ho = 0.215[ ± 0.213] to 0.314 [±0.236]) and average number of alleles(A = 2.0[± 0.858] to 2.38 [±0.868]). Very high values of P,Ho andA were also observed for the house mouse. Genetic distance (D) determined by using Nei’s (1978) formula in theM. terricolor complex ranged from the lowest,D = 0.082, betweenM. terricolor I and II to the highest,D = 0.155, betweenM. terricolor II and III. Genetic distance betweenM. booduga and theM. terricolor complex was 0-259 and that between the house mouseM. m. tytleri and theM. booduga-terricolor lineage was 0.285. TheseD values corroborate that the pygmy field and house mice are closely allied.

Biochemical genetics of Indian pygmy field mice: superoxide dismutase (Sod-1) as a diagnostic marker in Mus booduga.

Biochemical genetics of Indian pygmy field mice: superoxide dismutase (Sod-1) as a diagnostic marker in Mus booduga.

Chromosomal and molecular divergence in the Indian pygmy field mice Mus booduga-terricolor lineage of the subgenus Mus.

Mus booduga and Mus terricolor both have 2n = 40. Unlike M. booduga, with all acrocentric chromosomes, M. terricolor invariably has large submetacentric X and acrocentric Y due to an increase of heterochromatin. In contrast to the conservative karyotype of the co-existing sibling species booduga, three chromosome types of terricolor are found in different populations and their divergent karyotypes have autosomal heterochromatin variations established in the homozygous condition. The average genetic distance determined from electrophoretic study of 20 protein loci ranges from lowest (D = 0.106) between chromosome types I & II to highest (D = 0.185) between types II & III. In terricolor, booduga and M. m. tytleri high mean values of variations per locus (range A = 1.604 to 1.928) and heterozygosity per individual per locus (range H = 0.180 to 0.336) have been observed. Sequence divergence of 0.39 to 1.2%, calculated from restriction profiles of mtDNA, shows that the terricolor chromosome types have diverged recently. Hybridizations between type I females and type III males gave a preponderance of males in the F1 with varying degrees of sterility. The 'terricolor complex' is an interesting system for critical probing for the role of heterochromatin in the process of speciation. MtDNA, protein loci and AT-rich musculus-related major and minor satellite DNA data indicate that progenitors of the booduga-terricolor lineage might have evolved simultaneously with the caroli-cookii-cervicolor lineage in the evolution of the subgenus Mus.

The chromosomal distribution of Mus musculus-like AT-rich heterochromatin in the M. dunni complex as revealed by AluI digestion of metaphase chromosomes.

In situ digestion of metaphase chromosomes with AluI revealed differences in the distribution of Mus musculus-like AT-rich heterochromatin in the complements of the Indian pygmy field mice, M. booduga and M. dunni. In M. booduga, although the banding pattern was almost comparable to that of M. musculus, AluI-resistant bands were much reduced in size at the centromeric regions. In all three chromosome types of the M. dunni complex, M. musculus-like AT-rich heterochromatin was found to be confined mainly to two small segments on the short arm of the X chromosome. This AT-rich heterochromatin varied greatly in both position and quantity in the two X chromosomes. In addition to the polymorphism, a whole block of M. musculus-like AT-rich heterochromatin was found at the centromeric region of an autosome in one individual of M. dunni.

Constitutive heterochromatin and evolutionary divergence of Mus dunni, M. booduga and M. musculus.

The Indian pygmy field mice are one of the most interesting groups of animals from evolutionary point of view and include two morphologically extremely similar species Mus dunni and Mus booduga which share widely common natural habitats and until recently were considered conspecific. They are closely allied to the aboriginal mice Mus musculus and are distinguished from each other only on the basis of average characters (Ellerman 1961). The predominant diploid chromosome number in all the three species is 40 but while the karyotypes of M. musculus and M. booduga with all acrocentric chromosomes are identical, that of M. dunni is distinct due to invariable presence of large submetacentric X and acrocentric Y sex chromosomes. M. dunni populations from different localities also exhibit polymorphism in the number of biarmed autosomes (Matthey and Petter 1968; Sharma and Garg 1975; Markvong et al. 1975; Manjunatha and Aswathanarayana 1979; Sen and Sharma 1980/ 1983). The close morphometric and cytogenetic alliance of pygmy mice with a species like M. musculus that has been extensively utilized in molecular genetic and immunological investigations make these an attractive choice for detailed phylogenetic considerations.