Two post-graduate students have discovered a type of shrew never before seen in Ireland.

It is the first time in 44 years that a new mammal species has been found in the country.

The discovery was made by Dave Tosh from Belfast's Queen's University and John Lusby of UCC's Zoology, Ecology and Plant Science Department.

The two were investigating the diet of barn owls in Tipperary and Limerick and found skulls belonging to the greater white-toothed shrew in the birds' pellets.

They noticed that the skulls were unusually large for Ireland's native pygmy shrew.

The find led scientists to trap seven of the shrews alive at four locations in Tipperary last month.

The greater white-toothed shrew, Crocidura russula, has a natural range which extends across parts of Africa, France and Germany. It has been spotted before in the Channel Islands and the Scilly Isles.

Mr Tosh said the discovery came after a research officer from BirdWatch Ireland sent him pellets from owls in Tipperary and Limerick.

He added: 'It was amongst a batch that I was about to dry in an oven that I noticed a very large shrew skull.

'Having looked at hundreds of pellets from Ireland already I knew that what I was looking at was very unusual as our native pygmy shrew is very small in comparison.

'I ended up looking through more and more pellets and discovered more and more of the strange shrew skulls.'

John Lusby has been collecting the pellets as part of his PhD studies, collaborating with Mr Tosh.

Mr Lusby said they noticed the large shrew skulls in the pellets and knew they were different.

The animal is likely to have been introduced recently to Ireland.

About half of Ireland's estimated 60 mammal species are thought to have been brought to the island by humans.

The last new mammal to be discovered in Ireland was the bank vole in 1964.

Professor Ian Montgomery, head of the School of Biological Sciences at Queen's, said: 'Most species which occur in Ireland also occur in Britain but the nearest this species of shrew has been found is on the Channel Islands and the Scilly Isles.

'These records are evidence of at least one recent introduction event, probably accidental, from continental Europe to Ireland and has resulted in a rapid increase in numbers over a short period.'

He said the discovery raised ecological issues which need to be further studied.

While the creature is likely to help threatened birds of prey including the barn owl, it could lead to the loss of small native mammals including the pygmy shrew.