Communities of ectoparasitic arthropods associated with the root vole Microtus oeconomus in north-eastern Poland

Ectoparasitic arthropods communities associated with root voles Microtus oeconomus (Pallas, 1776) were analysed in north-eastern Poland. The first M. oeconomus parasites recorded in the history were the fleas Palaeopsylla similis Dampf, Ctenophthalmus congerer Rothschild, C. bisoctodentatus Kolenati, and C. solutus Jordan et Rothschild. Ctenophthalmus uncinatus (Wagner) and Doratopsylla dasycnema (Rothschild) fleas and the Ixodes apronophorus Schulze tick were recorded on M. oeconomus in Poland for the first time. These species are relatively rare in Poland and specific to other species of small mammals. The incidence of M. oeconomus infestations with I. apronophorus, D. dasycnema and C. uncinatus ranged from 0.5 to 0.8 %, respectively. There are large differences in the infestation of Dermacentor reticulatus larvae and nymphs between July and August. In July, D. reticulatus may be considered the dominant ectoparasite species, in August, it is partly replaced by I. ricinus and fleas and is subdominant.

Plant herbivore interactions: combined effect of ground water level, root vole grazing and sedge silication

1. Silicon mediated plant–herbivore interactions have gained increasing recognition and have now been studied in a wide range of species. Many studies have also considered accumulation of Si by plants as a process largely driven by geo-hydrological cycles. 2. To identify factors driving the water - plant Si - herbivore nexus we analysed the concentration of Si in fibrous tussock sedge (Carex appropinquata), the population density of the root vole (Microtus oeconomus) and the ground water level, over 11 years. 3. The largest influence of autumn Si concentration in leaves (Sileaf) was the level of the current year’s ground water table, which accounted for 13.3% of its variance. The previous year’s vole population density was weakly positively correlated with Sileaf and alone explained 9.5% of its variance. 4. The only variable found to have a positive, significant effect on autumn Si concentration in rhizomes (Sirhiz) was the current year spring water level explaining as much as 60.9% of its variance. 5. We conclude that the changes in Si concentration in fibrous tussock sedge are predominantly driven by hydrology, with vole population dynamics being secondary. Our results provide only partial support for the existence of plant-herbivore interactions, as we did not detect the significant effects of Si tussock concentration on the vole density dynamics. This was mainly due to low level of silification of sedges, which was insufficient to impinge herbivores. Future studies on plant–herbivore interactions should therefore mainly focus on identification of mechanisms and conditions allowing plants to accumulate silica at the levels sufficient to act as an anti-herbivore protection.

Genetic variability and conservation of the endangered Pannonian root vole in fragmented habitats of an agricultural landscape

The distribution of the endangered glacial relict subspecies, the Pannonian root vole Alexandromys oeconomus mehelyi Éhik, 1928, is restricted to scattered localities in south-western Slovakia, which belong to the north-eastern zone of its range. Human-induced changes and fragmentation of the landscape have led to the gradual loss of suitable habitats and threaten its long-term survival. The study area in the Danubian Lowland is characterised by small habitat fragments and temporal fluctuations of the habitat area. Root voles were sampled at nine sites to study the level of genetic variability and structure of local subpopulations by scoring 13 microsatellite loci in 69 individuals. Genetic differentiation varied amongst local populations and we did not find a significant isolation-by-distance pattern. Bayesian clustering analysis suggested that dispersal effectively prevents marked genetic subdivision between studied habitat fragments. Significant pairwise differentiation between some subpopulations, however, may be the result of putatively suppressed gene flow. Low genetic diversity in the recent populations probably reflects the isolated location of the study area in the agricultural landscape, suggesting that long-term survival may not be assured. In order to maintain genetic diversity, it is essential to preserve (or even restore) habitats and ensure the possibility of gene flow; habitat protection is, therefore, recommended. Continuous assessment is necessary for effective conservation management and to predict the long-term survival chances of the Pannonian root vole in the study area.

Biometric Analysis of Cranial and Somatic Features in the Pannonian Root Vole

The Pannonian root vole Alexandromys oeconomus ssp. mehelyi represents a rare glacial relict, whose occurrence is nowadays bound to several areas in Europe. Four somatic and 25 craniological features were analysed, based on 355 measured specimens. Sex is a significant factor affecting the average value of all four somatic features, where all of them achieve higher values in males than in females. While body length and tail length were also affected by seasons, body weight and the length of the hind foot were stable features present across the seasons. In cranial features, the largest variability in the adult population is characterised by neurocranium breadth (LaN), total length of the cranial base (LB), and skull (LCr); whereas the smallest variability of the cranial dimensions is reflected in the values of the greatest palatal breadth (PS) and postorbital breadth (Io). Calculating the weight from cranial remains may be used to estimate the size of the prey and to determine vole biomass consumed by predators, such as raptors, highlighting the utility of studying feeding ecology.

The effect of Pleistocene glacial morphogenesis on the genetic structure of the humid- and cold-tolerant root vole Microtus oeconomus (Rodentia, Cricetidae) in Poland, central Europe

During the Pleistocene in the northern part of Europe and Asia, the presence of ice sheets not only limited the range of species but also influenced landscape and thus the contemporary habitat system that determines the pattern of biodiversity. The aim of the research was to find out whether and how a lowland landscape, which formed as a result of subsequent Pleistocene glaciations (five) that in Eurasia covered various and generally successively smaller areas, affected the genetic differentiation of a species. The research was carried out in eastern Poland on the root vole Microtus oeconomus (Arvicolinae, Rodentia), a model boreal and hygrophilous species. Samples were collected from 549 vole individuals at 33 locations. Based on the analysis of 12 microsatellite loci and the 908 bp of cytochrome b sequences (mitochondrial DNA), the genetic structure of M. oeconomus in the landscape zones of the Polish Lowlands was determined. The results show that the latitudinal variability of the relief in eastern Poland (resulting from different ranges of Pleistocene ice sheets) and the related specific configuration of hydrogenic habitats are reflected in the genetic differentiation of the root vole. Therefore, it may be concluded that the history of landscape development affects the genetic structure of hydrophilic species.

Differences in the diet and trophic niche of three sympatric carnivores in a marshland

In order to conserve wetlands, it is crucial to have reliable knowledge of population and community processes. Our aims were to explore the dietary differences that allow coexistence of carnivores belonging to different trophic guilds, and to detect the presence of the relict Pannonian root vole subspecies (Microtus oeconomus méhelyi) within the Kis-Balaton marshland (Hungary). The 1-year dietary study was based on faecal analysis of the main mammalian predators of the area, i.e. red fox (Vulpes vulpes), martens (Martes spp.) and Eurasian otter (Lutra lutra). Small mammals, mainly Microtus species and water vole (Arvicola amphibius), were the primary foods for each carnivore. The dietary pattern of the otter was unique among European studies. Analysis of frequency data and estimated consumed biomass data revealed significant interspecific and intraspecific (seasonal) foraging differences among the three predators. Based on diets and live trapping of small mammals, foxes and martens selected voles, they selected against mice and shrews. The selection of the root vole was confirmed from faecal samples of foxes and martens. Consequently, faecal analysis of common carnivores can be an effective monitoring tool in providing data about prey species under special habitat conditions. Thus, it may contribute to wetland conservation indirectly.