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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. [ABSTRACT FROM AUTHOR]

Management decreases rodent numbers through reduction of vegetation height and cover along fence lines and other refuge habitats. Most farming practices remove vegetation and the short-term impact of mowing, mulching, harvesting and ploughing was studied on common voles (Microtus arvalis). Population dynamics and demographic parameters were estimated by live trapping before, and after farming practices were carried out. A gradient of disturbance according to the reduction of vegetation height, vegetation cover and nest sites is proposed. Estimates of vegetation height and vegetation cover before, and after farming practices fitted the model as well as the population response. It is concluded that only ploughing can suppress common vole populations the other farming practices being inappropriate to control pest rodents. [Copyright &y& Elsevier]

This study aimed to reveal changes in spatial behaviour of common voles (Microtus arvalis) after alteration of their habitat by farming practices. Radio-collared common voles were tracked before and after mulching, mowing, harvesting wheat, and ploughing in the flood plain of the river Unstrut in central Germany. Voles undisturbed by agricultural practices were tracked on a mulchland, an abandoned pasture, and a cattle pasture. There was a large decrease in home-range size after harvesting wheat (96%, P<0.001). Changes after mowing (–74%, P=0.06) were almost significant whereas changes after mulching were not (+14%, P=0.60). On the cattle pasture we found a decrease in home-range size (42%, P=0.03) possibly due to increased spatial activity of cattle in autumn. There was a positive correlation of home-range size and vegetation height for plots with and without farming activity but no correlation with vegetation cover, population density, and breeding. Radio-collared common voles did not show evasive movements and farming practices did not cause a shift of centres of activity. Common voles clearly reacted to sudden changes in vegetation height, which may indicate an immediate response to predation risk. [ABSTRACT FROM AUTHOR]

We used depletable food patches to determine the effect of microhabitat (mowed versus unmowed adjacent grasslands) and time (day versus night) on the foraging behavior of common voles (Microtus arvalis ). The food remaining after 12-h periods (giving-up density, GUD) measured the vole's habitat selection under predation risk. In accord with several other rodent species and the effects of avian predators, voles had significantly lower GUDs in the unmowed than mowed portion of the grassland. GUDs in patches along the border between adjacent habitats were more similar to the risky mowed grassland than the safe unmowed grass. Time interacted strongly with microhabitat. In the mowed grass, voles had significantly higher GUDs at night than day. Whereas in the unmowed grass, GUDs were significantly higher during the day than night. Vole GUDs did not vary with time along the boundary. This suggests that predators are more abundant or effective in the mowed grass at night (owls?), and in the unmowed grass during the day (weasels?). In terms of predation risk, the voles perceived the mowed grass at night as the riskiest and the unmowed grass at night as the safest. Voles may have difficulties assessing resources under high predation risk: GUDs among patches were well equalized in the unmowed microhabitat whereas in the mowed grass only day GUDs did not vary significantly among patches. We linked these results to the vole's day-night-activity and life span. For the 533 voles live-trapped at the study area, the ratio of day versus night captures for each individual served as an activity index and the span between first and last capture measured minimum life span. In accord with higher GUDs at night, very few individuals behaved selectively towards the night, but individual life expectancy increased with temporal opportunism. Microhabitat differences in GUDs reflect short-term strategies of predator avoidance and the trapping data reflect long-term patterns of anti-predator behavior. [ABSTRACT FROM AUTHOR]

Common voles (Microtus arvalis) can cause severe crop damage in European agriculture and are usually managed with rodenticides. Population dynamics and behavioral studies question rodenticide effectiveness, and an ecologically based management is needed. A useful addition to such a toolbox could be repelling odor barriers along field margins minimizing migration of voles to crops. We screened 17 plant products and mammalian scents in T-maze trials to test their repelling effects. The most repelling compounds (carrot seed oil (CS), black pepper oil (BP), spruce needle oil (SN), benzaldehyde (BA), BA and BP in double concentration (dc), combinations of BP + BA and BP + CS) were tested further in enclosures. We measured in four populations how often voles crossed enclosure compartments through channels treated with a compound or without a compound. In addition, the amount of rolled oats eaten by voles near treated and untreated channels was compared. In enclosures, voles avoided significantly channels treated with BP (79% more crossings through the control channel) and BP (dc) (42%). Voles consumed significantly more rolled oats near control channels than in the presence of BP + CS (72% more feeding at control), CS (51%), BA (dc) (36%), BP (32%) and BA + BP (28%). This demonstrated for the first time that natural compounds can reduce uptake of a highly attractive food source in common voles under semi-natural conditions. BP + CS was the most successful feeding deterrent and has the potential to be included in an ecologically based management approach. [ABSTRACT FROM AUTHOR]

Bait markers are indispensable for ecological research but in small mammals, most markers are invasive, expensive and do not enable quantitative analyses of consumption. Ethyl‐iophenoxic acid (Et‐IPA) is a non‐toxic, quantitative bait marker, which has been used for studying bait uptake in several carnivores and ungulates. We developed a bait with Et‐IPA, assessed its palatability to common voles (Microtus arvalis), and determined the dose‐residue‐relation for this important agricultural pest rodent species. Et‐IPA concentrations of 40 to 1280 μg Et‐IPA per g bait were applied to wheat using sunflower oil or polyethylene glycol 300 as potential carriers. In a laboratory study, common voles were offered the bait and blood samples were collected 1, 7, and 14 days after consumption. The samples were analyzed with LC‐ESI‐MS/MS for blood residues of Et‐IPA. Sunflower‐oil was the most suitable bait carrier. Et‐IPA seemed to be palatable to common voles at all test concentrations. Dose‐dependent residues could be detected in blood samples in a dose‐dependent manner and up to 14 days after uptake enabling generation of a calibration curve of the dose‐residue relationship. Et‐IPA was present in common vole blood for at least 14 days, but there was dissipation by 33–37% depending on dose. Et‐IPA meets many criteria for an "ideal" quantitative bait marker for use in future field studies on common voles and possibly other small mammal species. [ABSTRACT FROM AUTHOR]

Presents a correction to the article "Effects of Farming Practices on Spatial Behavior of Common Voles," by Jens Jacob and Nadine Hempel, published in the 2002 issue of the "Journal of Ethology."

Graphical abstract Highlights • Bisabolol, eugenol and maltol attract common voles in T-maze trials. • Maltol improves trapping success in common voles in enclosed populations. • Maltol could be used to improve the tool box for ecologically-based rodent management after testing under field conditions. Abstract Common voles are serious pests in European agriculture, damaging cereals, rapeseed and other crops and causing substantial losses per outbreak. Not only might the usual approach of applying rodenticides for population management have disadvantages for non-target species, these rodenticides also cannot be used in organic farming. An alternative solution could be an approach related to the concept of ecologically-based rodent management combining environmentally sustainable methods based on knowledge about the target species. Such a method inhibits the dispersal of common voles from field margins to crop habitats via a trap-barrier system. However, little is known about attractants, which could increase the trapping success of common voles. We screened 22 natural substances in T-maze trials. The three most successful substances were further tested during enclosure trials under semi-natural conditions. Bisabolol, eugenol and maltol attracted six of eight voles during the T-maze trials and were mixed into grain pellet bait. Bait containing maltol caught significantly more common voles in enclosures than plain control bait or bait containing bisabolol or eugenol. Of all individuals, 21% chose exclusively baits with maltol. Generalized Linear Mixed Model (GLMM) indicated that every individual would be trapped once in 6 h with this bait type and GLMM predicted that 63% of females and 56% of males would choose this bait over plain control bait. Maltol bait could help either by more efficiently trapping common voles in a trap-barrier system or improving bait acceptance when rodenticides are applied. [ABSTRACT FROM AUTHOR]

Rodents, including common voles ( Microtus arvalis) and house mice ( Mus musculus) cause immense pre-harvest and post-harvest losses. Therefore, developing methods that mitigate these losses while maintaining their role in ecosystems is a priority. Several plant secondary metabolites (PSM) which significantly reduce food intake of both species under laboratory conditions have been identified. However, before these can be used in rodent pest management, they must be tested under more natural conditions where other food sources are available. In this study, the odors of 4 PSMs were evaluated for their repellent effects in experiments conducted in semi-natural enclosures. Soil treated with PSMs or untreated soil (experimental control) was placed in an underground box containing food (rolled oats). We quantified the number of visits to each box and could demonstrate that all 4 PSMs reduced the number of visits to treatment boxes in both rodent species. For common voles the combination of methyl nonyl ketone + black pepper oil was the most repellent PSM. House mice made fewer visits to all PSM boxes; boxes with the anthraquinone were visited least. Furthermore, house mice consumed less food from boxes containing soil treated with all 4 PSMs. Our results suggest that PSMs are repellent in murid and microtine rodents under semi-field conditions. In addition, the future use of PSM odors for repelling both pest species, especially house mice, seems promising. Further investigations with other PSMs, different concentrations as well as alternative application methods are needed to repel common voles from attractive crops. [ABSTRACT FROM AUTHOR]

Tula virus (TULV) is a vole-associated hantavirus with low or no pathogenicity to humans. In the present study, 686 common voles ( Microtus arvalis), 249 field voles ( Microtus agrestis) and 30 water voles ( Arvicola spec.) were collected at 79 sites in Germany, Luxembourg and France and screened by RT-PCR and TULV-IgG ELISA. TULV-specific RNA and/or antibodies were detected at 43 of the sites, demonstrating a geographically widespread distribution of the virus in the studied area. The TULV prevalence in common voles (16.7 %) was higher than that in field voles (9.2 %) and water voles (10.0 %). Time series data at ten trapping sites showed evidence of a lasting presence of TULV RNA within common vole populations for up to 34 months, although usually at low prevalence. Phylogenetic analysis demonstrated a strong genetic structuring of TULV sequences according to geography and independent of the rodent species, confirming the common vole as the preferential host, with spillover infections to co-occurring field and water voles. TULV phylogenetic clades showed a general association with evolutionary lineages in the common vole as assessed by mitochondrial DNA sequences on a large geographical scale, but with local-scale discrepancies in the contact areas. [ABSTRACT FROM AUTHOR]