The public is being asked to keep their eyes open for grey squirrels as part of a national survey to detect whether the pest’s numbers are continuing to increase — at the expense of the native red squirrel.
The last all-Ireland squirrel survey took place five years ago. It found that grey squirrels had not penetrated counties Cork and Kerry nor west of the Shannon to counties Clare, Galway, Mayo and Sligo.
The Shannon had acted as a natural barrier.
However, there have been confirmed sightings in subsequent years of the grey squirrel in the North Cork area, according to University College Cork.
Grey squirrels are a major threat to the survival of the native red squirrel and to the future of broadleaf trees as they destroy vigorous healthy trees through bark stripping.
They also carry a pox virus which kills the native red species.
Recently there have been reports of two cases of the virus in Co Wicklow and another in Antrim.
If landowners see grey squirrels on their land, zoologists will show them how to trap and kill the pest.
The 2007 all-Ireland squirrel survey showed a “dramatic increase in the spread of the grey squirrel over the past 20 years”, according to Dr Michael Carey, a forestry and management consultant who is helping NUI Galway’s mammal ecology group complete this year’s research.
It also showed there were 200,000-300,000 grey squirrels in Ireland while there were only a quarter as many red squirrels.
Counties such as Tipperary, Wicklow, Carlow, and Kilkenny had particularly high populations of the grey pest.
“With the increased planting of broadleaf trees over the last two decades, woodland owners and the public need to be vigilant with regard to the threat posed by grey squirrels and on the extent to which they can destroy vigorous healthy trees through bark stripping and eliminate red squirrels,” said Dr Carey.
The new survey aims to pinpoint the most vulnerable areas in the country and ensure strategies are in place to minimise further tree damage and spread of the pest.
It began in January and will continue until next month.
The grey squirrel, an invasive species, was only introduced to Ireland 100 years ago when it was brought onto lands at Castleforbes Estate in Co Longford.
* Sightings can be easily recorded on a form on www.woodlandmammals.com by emailing email@example.com.
Hard copies of the form are also available from Margaret Flaherty, Mammal ecology group, Martin Ryan Institute, NUI Galway.
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