Geographic isolation of small populations in refugia during late Pleistocene glaciations resulted in population differentiation that in some cases lead to speciation. We report the karyotype of Microtus bavaricus, an evolutionary young and threatened rodent endemic to the Alps. Our results show that the karyotype of M. bavaricus is almost identical to that of M. liechtensteini (2N = 46, NF = 54). A close relationship between the two species was also supported by phylogenetic analysis of complete mitochondrial DNA sequences for the cytochrome b gene. The cytochrome b divergence between Microtus bavaricus and M. liechtensteini was 1.7 %, the lowest estimate observed among the 14 currently recognised species of Eurasian pine voles (subgenus Terricola).
An international conference titled Knowledgeable Society took place in Prague on March 10,2011 under the aegis of the Czech Prime Minister Petr Nečas. Organizers of the conference directed attention on actual questions of science and education a world-wide context. and Vladimír Čechák, Jan Zima.
More than one thousand rodent remains have been found in three different lacustrine sediment beds of Miocene age at Bełchatów (Poland) - an opencast brown coal mine. Three fossil assemblaged (Bełchatów C - the oldest, Bełchatów B and Bełchatów A) contain abundant rodent remains (mainly teeth) and correspond to biostratigraphic zone MN 4/5, MN 5/6 and MN 8/9, respectively. Aboud 80% of the rodent material was found in the uppermost layer (Bełchatów A). The remaining two assemblages, of not dissimilar ages and with similar Orleanian/ Astaracian faunas, countain 11% (Bełchatów B) and 9% (Bełchatów C) of the material studied. Most species (except for the relatively numerous Sciuridae and Castoridae and one dipodid tooth) have already been described. However, recent studies on cricetids and eomyids have led to a revision of the previously proposed ages of Bełchatów C and Bełchatów A.
Based on ecological parameters of 15 localities with birch mouse (Silista betulina) occurrence a model of its potential distribution in a part of the Bohemian Forest (Šumava) in Czech Republic was set up. The following habitat parameters were included into the model: land cover (six classes), proximity to next cover type (ten classes), proximity to a stream (five classes), altitude (seven classes), slope (seven classes), exposition (four classes). These parameters were derived from the Landsat 5 TM data and from digital elevation model using EASE/PACE software. All raster format data had a 30 m pixel size and all geographical information system layers were rectified into maps scale 1 " 25,000, Gauss-Krüger projection. For each of the six parameters two histograms were calculated. The first one displayed the frequency of a membership of a pixel to a class under a mask of the whole study area and the second histogram under a mask of the area of the birch mouse occurrence. The birch mouse preferred: the closest proximity to a stream (0-60m), flat terrain (slope < 5°), north-eastern and south-eastern expositions, the altitude between 700-900 m a. s. l., unmanaged meadows and pasture, boundaries between meadows and pastures or meadows and forests. The overall probability of the occurrence calculated according to these factors revealed areas of the most probable occurrence above all along the Vltava river system. This model was successfully verified by pitfall trap collection of birch mouse in three randomly chosen localities with the highest calculated probability of the occurrence.
Two chromosomal races of the house moue occur in central Tunisia: a standard type (2n = 40) and a Robertsonian race (2n = 22). Although contact between races is not restricted, hybrid populations are rare. Patterns of mate preference between wild mice of the two races suggest that, although incipient, this premating divergence could limit the number of crosses between races in nature. In this paper we compare sexual preference of laboratory-born mice and their parents caught as adults in the wild with the aim to assess whether the social context of development to adulthood could influence expression of preference. We predict that in the absence of such influence, parents and laboratory-born offspring should show a comparable pattern of preference. Results show that offspring preference is always lower than and not related to that of their parents. However, a significant pair effect exist leading us to group parents and offspring into three categories according to the parents' preference: homokaryotypic, heterokaryotypic, or dissimilar. Offspring exhibit a preference, which is consistent with that of their parents, only in two cases: male offspring of the standard race when both parents show a heterokaryotypic preference; all offspring when the homokaryotypic preference of fathers is high. Discrepancy between preferences of wild-caught mice and their laboratory-born progeny suggests that, here, preference may be partly influenced by social conditions experienced before and during adulthood.
The species richness of free-living vertebrates was analysed using mapping of occurrence within individual grid squares (12 x 11.1 km) over the territory of the Czech Republic. The data on species distribution were derived from recent distributional atlases published in the last 15 years, and the records originated mostly in the last 20 years. Altogether, 384 species of cyclostomes, bony fishes, amphibians, reptiles, birds and mammals were included in this study and their presence or absence was recorded in 678 grid squares. The species numbers ascertained in the 523 grid squares situated completely within the Czech Republic varied from 92 to 259 species, with a median of 182 species. The first two principal components explained 44.9 % of the total variance and separated two main habitat gradients based on values of different environmental, topographic, and demographic variables in particular squares. The PC1 represents a gradient from urban habitats at lower altitudes to more homogenous habitats with dominant coniferous forests and meadows situated at higher altitudes. The importance of natural habitats (represented by broad-leaved and mixed forests, as well as by protected areas) and landscape heterogeneity increases along the PC2. Generalized Linear Modelling for each group of vertebrates was fitted using the number of species of individual vertebrate groups as a response variable and the first two principal components as explanatory variables. The species richness of all vertebrate groups except for reptiles is highly dependent on the PC1. The number of fish, amphibian, and bird species in squares decreases with increasing value of the PC1, i.e. it is higher in urban areas at lower altitudes. By contrast, the number of mammal species is higher in uninhabited areas at higher altitudes. The gradient represented by the PC2 is highly significant for species richness of reptiles and mammals, and the number of species of both groups increases with increasing importance of natural habitats.