A MAMMAL species new to Ireland, the greater white-toothed shrew, has been found in the midwest where it is believed to be well established.
Evidence that the shrew had arrived here was spotted by Dave Tosh, Queen’s University Belfast, and John Lusby, University College Cork and BirdWatch Ireland, when examining regurgitated food remains of barn owls and kestrels from 15 Tipperary and Limerick sites.
Shrews were later trapped at four locations in Tipperary in March but it is still unclear what impact it is having on the ecology of habitats in which it is found.
Mr Lusby said the find took them by surprise when they discovered 53 skulls of the little animal in 10 barn owl pellets.
Prof Ian Montgomery, of Queen’s University, said that these records were evidence of at least one recent introduction event, probably accidental, from continental Europe, and that this has resulted in a rapid increase in numbers over a short period.
He speculated that association with human habitation, social nesting and the high reproductive potential of greater white-toothed shrews may have helped it reach Ireland among horticultural imports such as root balls of trees and then rapidly expand.
Prof John O’Halloran, of University College Cork, noting the high frequency of shrew remains in bird of prey pellets, suggested that there was potential for the greater white-toothed shrew to “become a major prey item of avian predators in Ireland where there is an impoverished small mammal fauna compared to Britain”.
Initial analysis of barn owl pellets suggested that the introduction of this latest mammal may also prove particularly beneficial for threatened predators such as the barn owl. On the downside, the newcomer has the potential to displace other shrew species such as the pygmy shrew, regarded as part of Ireland’s native fauna.
As with other recently introduced mammal species (the grey squirrel, mink, brown hare and bank vole), the greater white-toothed shrew raises issues related to ecological impact and control, said BirdWatch Ireland last night.