Common voles (Microtus arvalis) are widespread in the European agricultural landscape from central Spain to central Russia. During population outbreaks, significant damage to a variety of crops is caused and the risk of pathogen transmission from voles to people increases. In 2019, increasing or unusually high common vole densities have been reported from several European countries. This is highly important in terms of food production and public health. Therefore, authorities, extension services and farmers need to be aware of the rapid and widespread increase in common voles and take appropriate measures as soon as possible. Management options include chemical and non-chemical methods. However, the latter are suitable only for small and valuable crops and it is recommended to increase efforts to predict common voles outbreaks and to develop and field test new and optimized management tools. Keywords Microtus arvalis • Rodent-borne diseases • Rodent management • Rodent outbreaks • Rodent damage Key message • Common vole populations are synchronously rising in several countries indicating a massive European-wide outbreak. • Non-chemical management options for the protection of large-scale crops are scarce and insufficient in agriculture and forestry. • Significant damage by common voles in 2019 to crops and negative effects on human health are likely. • Authorities, extension services and farmers need to be aware of the rapid and widespread increase in common voles.

Feeding habits and interspecific trophic niche overlap of two sympatric predators, the pine marten Martes martes and the red fox Vulpes vulpes, were studied in a deciduous forest habitat in Hungary with conditions of differing abundance and dominance in the rodent community. The main food source of the predators consisted of small mammals, mainly rodents. Consumption of small mammals was higher during bank vole Clethrionomys glareolus dominated years than in Apodemus mice dominated years. Both predators preferred bank voles as prey and consumed less Apodemus mice and shrews (Soricidae) than expected by availability. The two opportunistic predators utilised different, seasonally-dependent food resources. Martens consumed more plants, reptiles, amphibians and fish, whereas foxes consumed more small mammals and ungulate carcasses. In summer and autumn, percent biomass of bank voles in marten diet and Apodemus mice in fox diet was positively correlated with the number of rodents in the available food resources. In winter and spring, the density of rodents varied slightly; therefore, variations in the diets of these two predators were not related to prey density. The prey consumed was characteristically terrestrial and small sized (, 50 g). There was no difference in prey weight distribution between martens and foxes, but martens consumed more arboreal and foxes more terrestrial prey. The standardised food niche breadth did not differ significantly between the two species. Food niche overlap between the two predators was higher in winter and spring, but the difference between seasons was not significant (mean overlap 5 72%). In comparison with higher latitudes, we found a larger food niche overlap in our study.

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.

Phenetic and ecological plasticity in Arvicola has caused a long-standing dispute over the number of species within the genus, which is currently thought to consist of two aquatic (sapidus, amphibius) and one fossorial species (scherman). We used mitochondrial cytochrome b (cytb) gene sequences to reconstruct phylogenetic relationships between the fossorial and the aquatic water voles from the various regions of their European and Asiatic range. These two types differed morphologically and exhibited allopatric ranges. Our study provided 50 new haplotypes, generating a total dataset of 70 different water vole cytb haplotypes. Phylogenetic reconstructions retrieved two major lineages that were in a sister position to A. sapidus: a fossorial Swiss lineage and a widespread cluster, which contained aquatic and fossorial water voles from Europe and western Siberia. The phylogeographic architecture in water voles is explained by Quaternary climatic dynamics. Our results show that A. scherman in its present scope is not a monophyletic taxon.

Rodents are important reservoir hosts for several zoonotic pathogens that cause significant morbidity and mortality in humans. Among others, leptospirosis is one of the most widespread zoonotic diseases worldwide and has the similar clinical manifestation with hantavirus infection in humans. Despite the fact that both pathogens have great epidemiological significance in Europe, no epizootiological data exist for urbanized areas so far. Therefore, this study was conducted to investigate the occurrence and prevalence of Leptospira spp. and hantaviruses in small wild rodents living in close proximity to humans. Altogether, 338 small rodents representing five different species (Apodemus agrarius, A. flavicollis, A. sylvaticus, Microtus arvalis, and Myodes glareolus) were captured in the city of Pécs (Hungary) and screened for pathogens by different types of PCR methods (TaqMan-based real-time PCR/PCR, RT-PCR/PCR). A total of 18.3% of the rodents were positive for Leptospira kirschneri, L. interrogans, and L. borgpetersenii. Nucleic acid of Tula hantavirus and human pathogen Dobrava-Belgrade orthohantavirus were detected in 8% of tested specimens. Furthermore, dual infections with both Leptospira spp. and hantaviruses were shown in 2.6% of animals, suggesting that the same rodent host can be infected with several pathogens at the same time, therefore, representing a serious threat to public health. Overall, this study provides important surveillance data on the prevalence of Leptospira spp. and hantaviruses from rodents in urbanized environment for the first time in Hungary and emphasizes the importance of further ecoepidemiological investigations.