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For good or ill Ireland gains another mammal species
Although there are only about 60 species of mammals living inland or around our coasts, they play an important part in our lives.
Ireland has long been separated from mainland Europe, thereby, preventing movement over land.
There are a greater number of mammal species in Britain than here. It must not be forgotten that over 50% of the mammal species in Ireland have been introduced by man so this is the context in which you should read the following news items:
Dave Tosh, from the School of Biological Sciences at Queens University, found the greater white-toothed shrew in Tipperary and Limerick while working with University College Cork and BirdWatch Ireland. Its natural range is in parts of Africa, France and Germany and before now the closest it has been spotted to Ireland is in the Channel Islands.
As part of his PhD, Dave was studying the diet of the Barn Owl in Ireland. Last winter John Lusby, Barn Owl Research Officer from Bird Watch Ireland, sent him pellets (regurgitated food remains) from owls in Tipperary and Limerick to help with the study.
Dave explained: “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.”
In March seven greater white-toothed shrews were trapped at four locations in Tipperary and their existence has just been recorded in the scientific journal Mammal Review.
Professor Ian Montgomery, Head of the School of Biological Sciences at Queen’s, says the animal is likely to have been introduced recently to Ireland and the discovery of a new mammal species in Ireland is extremely rare.
“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.”
The discovery, however, raises issues related to ecological impact and control which need to be further researched. While the shrew is likely to sustain threatened birds of prey including the barn owl, it could lead to the loss of small native mammals including the pygmy shrew.
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.
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April 28, 2008 at 03:28 pm by infomatique, 288 views, add comment


