New mammal in westmeath

The pygmy shrew’s days could be numbered in Westmeath following the arrival of an “aggressive” continental cousin, according to a leading environmentalist.

A native of mainland Europe and North America, the greater white toothed shrew was first identified in Munster six years ago and its presence was recently recorded by scientists in the Mullingar area. John Lusby, raptor conservation officer with Birdwatch Ireland, first came across the greater white toothed shrew while studying the diets of barn owls.

“We came across skulls of these mammals and that was the first record of them occurring in Ireland, so they are a fairly recent discovery,” said John.

“They’ve become well established, particularly in the core range, which is south Tipperary, east Limerick – but they’ve spread now. There is a separate population in Cork, there is a separate population around Mullingar, so they seem to spreading relatively quickly.”

“How the mammal, which is twice the size of the indigenous pygmy shrew, arrived on our shores remains a mystery,” John says, “but it appears to be making its mark.

“Obviously with every non-native species there is potential for both positive and negative impacts. What we have seen is that it seems to be displacing the pygmy shrew, which is the only other species of shrew we have in Ireland... Wherever the greater white toothed shrew occurs in big numbers, pygmy shrews are absent.

“The greater white toothed shrew is a more aggressive species, and about twice the size. There is quite an overlap in terms of food resources so there obviously is something going on there – it might be due to competition, but we don’t know the dynamic well yet in terms of negative impact on pygmy shrews, but it does seem to be the case.”