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All observations of collectively migrating larvae of the family Sciaridae recorded after 1945 in Poland are given. The phenomenon was observed in the mountains (S Poland) as well as in the lowlands of central and north-eastern Poland, mainly in forest habitats. The influence of climatic factors was analysed for the data from the Białowieża Primeval Forest. Air temperature and humidity may influence the appearance of migrating larvae.
Cyclic population dynamics of small mammals are not restricted to the boreal and arctic zones of Eurasia and North America, but long-term data series from lower latitudes are still less common. We demonstrated here the presence of periodic oscillations in small mammal populations in eastern Poland using 22-year (1986–2007) trapping data from marginal meadow and river valley grasslands located in the extensive temperate woodland of Białowieża Primeval Forest. The two most common species inhabiting meadows and river valleys, root vole Microtus oeconomus and common shrew Sorex araneus, exhibited synchronous periodic changes, characterised by a 3-year time lag as indicated by an autocorrelation function. Moreover, the cycles of these two species were synchronous within both habitats. Population dynamics of the striped field mouse Apodemus agrarius was not cyclic. However, this species regularly reached maximum density 1 year before the synchronized peak of root voles and common shrews, which may suggest the existence of interspecific competition. Dynamics of all three species was dominated by direct density-dependent process, whereas delayed density dependent feedback was significant only in the root vole and common shrew. Climatic factors acting in winter and spring (affecting mainly survival and initial reproduction rates) were more important than those acting in summer and autumn and affected significantly only the common shrew. High temperatures in winter and spring had positive effects on autumn-to-autumn changes in abundance of this species, whereas deep snow in combination with high rainfall in spring negatively affected population increase rates in common shrew.
Using a root vole Microtus oeconomus (Pallas, 1776) population in NE Poland we applied 31 microsatellite markers previously developed for root voles and closely related species, with the aim to improve the population genetic tools in this species. Here we present 16 polymorphic microsatellite markers grouped into four sets suitable for simultaneous amplification and genetically sex identification in M. oeconomus. The number of alleles per locus in 227 individuals varied from 7 to 26 with a low frequency of null alleles, expected heterozygosity ranged from 0.758 to 0.927, and observed heterozygosity from 0.722 to 0.947. Two loci showed significant deviation from Hardy-Weinberg equilibrium (p<0.05) and all loci showed independent inheritance. We expect these markers to be useful for studies of genetic population structure and kinship of M. oeconomus populations.
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