Crocidura russula | Greater White-toothed Shrew
First reported in the wild
Invasive species - risk of Medium Impact
Introduction pathways - 1
NAPRA Ireland risk assessed
Feeds on a wide variety of invertebrates (Churchfield, 2008). Studies have shown that it has a negative impact on the abundance of wood mouse (Apodemus sylvaticus)and the occurrence of the pygmy shrew, though the mechanism is unclear (Montgomery et al., 2012), with the pygmy shrew completely absent at sites where C. russula is established. It appears to a positive impact on the occurrence of the bank vole (
Woodland, forest and other wooded land; Regularly or recently cultivated agricultural, horticultural and domestic habitats; Grasslands and lands dominated by forbs, mosses and lichens
Litter size typically 2-11 with a mean of 4, producing several litters a year with a gestation period of 28-33 days (Churchfield, 2008).
Pathway and vector description
It is not known at present how this species entered Ireland but it is thought to have been present since at least 2001, despite only being reported in 2008.
Mechanism of impact
Competition, Interaction with other invasive species, Other
Found in hedgerows, wooded land, grassland and cultivated areas (Churchfield, 2008).
Pygmy shrew (Sorex minutus)
Established - Widespread and expanding. Range estimated at 7,600km2 in 2013, with a rate of expansion of 0.5-14.1km/yr depending on landscape characteristics (McDevitt et al., 2014).
Native range extends from central Germany to Iberia and into Northern Africa (Churchfield, 2008)
Date of first record category
Fifty year date category
Records submitted to Data Centre in 2021
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How can you help
Report any sightings to the National Biodiversity Data Centre.
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.
Churchfield, S. (2008) Greater white-toothed shrew Crocidura russula In: Mammals of the British Isles: Handbook, 4th Edition. (Eds) Harris, S. & Yalden, D.W. The Mammal Society, Southampton.
McDevitt, A.D., Montgomery, W.I., Tosh, D.G., Lusby, J., Reid, N., White, T.A., McDevitt, C.D., O'Halloran, J., Searle, J.B. and Yearsley, J.M., (2014). Invading and expanding: range dynamics and ecological consequences of the greater white-toothed shrew (Crocidura russula) invasion in Ireland. PLoS One. 2014 Jun 23;9(6):e100403. doi: 10.1371/journal.pone.0100403. eCollection 2014