American Grey Squirrel ~ Sciurus carolinensis on my Pergola. The Original pair of American Grey Squirrels were brought form America as a Wedding Present to a couple in Co. Longford in 1910. Since then they escaped in to the Wild & have multiplied.............. The problem is they carry Squirrel Pox that does not affect them but is fatal to our native smaller Red Squirrel. Recently the reintroduction of the Pine Marten has helped the Red Squirrels to recover somewhat, as they are able better to escape the Pine Marten while the American Grey Squirrels are more liable to fall prey to them. Susan