Halting march of grey squirrel

THE American grey squirrel, and its flea, arrived here from England in 1911 when a ‘scurry’ was presented to the bride during wedding celebrations at Castleforbes County Longford.

Released into the countryside, the intruders and their descendants prospered. They have colonised eastern and northern counties, displacing the resident red squirrels everywhere. This alien also strips bark from trees. A report on the Irish Squirrel Survey claims that “commercial broad-leaf crops can be written off and native trees left severely damaged … If left unchecked, the grey squirrel will severely curtail both commercial hardwood production and the conservation and expansion of native hardwood cover in Ireland”.

The survey, carried out in 2007, found that greys had “expanded their range dramatically” during the previous decade and that they had “breached the Shannon in a few places”. The grey is now in 26 Irish counties and, at current rates of expansion, will colonise three more in the next two decades. Trapping and shooting are ineffective in controlling it but, thanks to a discovery made during the squirrel survey, there is a glimmer of hope. Surveyors seem to have found the grey squirrel’s Achilles heel; there is a native animal which may be able to halt the expansion. We might even recover some lost ground. The scientists are tight-lipped, but a remarkable research project is underway at NUI Galway.