Barn owl helps to find new Irish shrew

Paul Eccleston, The Telegraph 28 Apr 08;

A species of shrew has been found in Ireland for the first time - after it was discovered it was featuring on an owl's menu.

Scientists were alerted by the size of a skull found in food remains passed by a Barn owl. They eventually managed to trap several of the greater white-toothed shrew to prove that it has taken up residence.

It is only the third new mammal to be found in Ireland in almost 60 years.

The shrew is normally found in parts of Africa, France and Germany and the closest it has previously been spotted to Ireland is the Channel Islands.

It is not known how the shrew arrived but the scientists believed it was introduced only recently.

Dave Tosh, from the School of Biological Sciences at Queens University, found the shrew in Tipperary and Limerick in the south-west of Ireland.

He was studying the diet of the Barn owl in Ireland as part of his PhD last winter when he was sent pellets - regurgitated food remains - from owls to help with the study by John Lusby, Barn Owl Research Officer from Bird Watch Ireland.

"It was amongst a batch that I was about to dry in an oven, that I noticed a very large shrew skull," he said.

"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 now been recorded in the scientific journal Mammal Review.

Professor Ian Montgomery, Head of the School of Biological Sciences at Queen's, who helped trap the shrew, said 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," he said.

"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 shrew - which is a prolific breeder producing multiple litters of up to 11 kits at a time - had found perfect conditions in the Irish countryside.

"The shrew is at time communal and it may be that a whole nest arrived at the same time allowing them to spread out quite quickly. A wildlife survey was carried out in the area in 2002-2003 and there was no trace of the shrew so it is quite possible it has been here for only five years."

The biologists will now investigate the ecological impact of the shrew's arrival. While it will provide an additional source of food for birds of prey, it may also be a competitor of small native mammals including the pygmy shrew.

The two other mammals new to Ireland are the Bank vole - thought to have arrived in a consignment of German-made hydro-electric equipment in the 1950s, and the Nathusius pipistrelle bat which probably crossed the Irish Sea from mainland Britain.

New shrew discovered in Ireland
Yahoo News 28 Apr 08;

Ireland, which has seen an immigration surge in recent years, has a new foreigner on its shores, scientists said Monday: the greater white-toothed shrew.

The mammal, Crocidura Russula, has been discovered in parts of the midlands and south-west of the republic. Its natural range is in parts of Africa, France and Germany.

Professor Ian Montgomery, head of the School of Biological Sciences at Queen's University in Belfast, 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."

He said the discovery was probably the result of an accidental introduction from "continental Europe to Ireland and has resulted in a rapid increase in numbers over a short period".

The shrew, which has been spotted in Counties Tipperary and Limerick, is only the third new mammal to be found on the island in almost 60 years.

The presence of the new immigrant came to light when Dave Tosh, from Queen's University, was studying the diet of the Barn Owl while working with University College Cork and BirdWatch Ireland.

Analysing owl pellets (regurgitated food remains) sent to him by John Lusby, Birdwatch's barn owl research officer, Tosh began to find large shrew skulls, too big to be the skulls of Ireland's native pygmy shrew.

Last month, the presence of the greater white-toothed shrews was confirmed when seven were trapped at four locations in Tipperary.

The discovery now raises issues of ecological impact and control.

The scientists say that while the new 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.