THEY come over here and they… compete with our indigenous rodent species.
The River Shannon might be the only thing to tame the march of a recently discovered shrew threatening to make one of its closest relatives extinct.
Invasive miniature mammal the greater white-toothed shrew – three times the size of its rival, the pygmy shrew – is on course to be in every part of the island by 2050 if it can cross the natural barrier.
Researchers from University College Dublin (UCD) warned that in the seven years since the furry creature was discovered, it has colonised 7,600 sq km in seven counties.
Dr Allan McDevitt, UCD School of Biology and Environmental Science and lead author of the study, said ‘there may not be sufficient landscape complexity in Ireland to allow niche partitioning between these two species of shrew’.
The study, published in the journal PLOS ONE, found the greater white-toothed shrew now has a habitat stretching across Tipperary, Limerick, Cork, Waterford, Kilkenny, Offaly and Laois, and in parts of Cork city and Mullingar.
The fight for food and habitat has seen the pygmy shrew become extinct in parts of Tipperary after thousands of years. Its competitor, first found in Ireland in the pellets of barn owls and kestrels in 2007, has spread at more than 5km a year.
The researchers have called for authorities north and south to address the issue of invasive species causing severe ecological impacts across the island.