Myodes glareolus | Bank Vole | Vól bruaigh
First reported in the wild
Invasive species - risk of Medium Impact
Introduction pathways - 1
Introduction pathways subclass - 1
NAPRA Ireland risk assessed
Superficially appears similar to a large mouse, though with less pronounced ears. Brown in colour and 9-11cm in length (Shore & Hare, 2008).
Largely herbivorous with1-16% animal matter, 20-40% Seeds and green leaf material 40-50% depending on the region (Shore & Hare, 2008). Show significant dietary overlap with the wood mouse (Apodemus sylvaticus
A removal experiment in Italy found that there is asymmetrical competition between the bank vole and the wood mouse with removal of wood mice leading to a strong increase in population density of bank voles but not the reverse (Fasola & Canova, 2000). However studies on farmland in Ireland have shown that wood mouse densities are negatively associated with bank vole abundance (Montgomery et al., 2012) and it appears to be contributing to an 'invasional meltdown' (a process whereby one invasive species assists another in spreading) helping the greater white-toothed shrew (Crocidura russula) displace the native pygmy shrew (Sorex minutus) (Montgomery et al., 2012).
Woodland, forest and other wooded land; Regularly or recently cultivated agricultural, horticultural and domestic habitats; Grasslands and lands dominated by forbs, mosses and lichens
Promiscuous mating system producing a mean litter size of 4.8, females can breed within the first year if born early in the breeding season and can produce litters at intervals of 3-4 weeks (Shore & Hare, 2008).
Pathway and vector description
Though only recorded in 1964 DNA techniques suggest the species was introduced in the 1920s, possibly with equipment and machinery at Ardnacrusha, as the population in Ireland is related to the west German population of bank voles (Stuart et al., 2007). From there they have spread at a rate of ~2km per year to cover an area of 32,700km squared by 2011 (Montgomery et al., 2012).
Mechanism of impact
Competition, Interaction with other invasive species
Common in mixed and deciduous woodland, conifer and spruce plantations, hedgerows, grassland and road verges (Shore & Hare, 2008).
Established - Widespread and spreading. Common in the west and spreading from point of entry covering approximately 40% of the country.
Native to Europe from the Arctic Circle to Italy (Shore & Hare, 2008)
Date of first record category
Fifty year date category
Records submitted to Data Centre in 2019
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How can you help
Report any sightings to the National Biodiversity Data Centre.
Fasola, M. and Canova, L., 2000. Asymmetrical competition between the bank vole and the wood mouse, a removal experiment. Acta Theriologica,45(3), pp.353-366. Claassens, A. J. M. & O’Gorman, F. (1965) The bank vole Clethrionomys glareolus Schreber: a mammal new to Ireland. Nature, London 205: 923-924. Stuart, P., Mirimin, L., Cross, T.F., Sleeman, D.P., Buckley, N.J., Telfer, S., Birtles, R.J., Kotlik, P. and Searle, J.B., 2007. The origin of Irish bank voles Clethrionomys glareolus assessed by mitochondrial DNA analysis. The Irish Naturalists' Journal, pp.440-446. Montgomery, W.I., Lundy, M.G. and Reid, N., 2012. ‘Invasional meltdown’: evidence for unexpected consequences and cumulative impacts of multispecies invasions. Biological Invasions, 14(6), pp.1111-1125. White, T.A., Perkins, S.E., Heckel, G. and Searle, J.B., 2013. Adaptive evolution during an ongoing range expansion: the invasive bank vole (Myodes glareolus) in Ireland. Molecular ecology, 22(11), pp.2971-2985.