The Grey Squirrel

A cute little furry thing but scorned by wildlife managers and conservationists. Native to North America the grey squirrel was introduced into Britain by Victorian landowners to enhance their gardens and estates and is now common and widespread. It is considered an invasive non-native species, causes damage to our woodland and wildlife and has pushed out our native red squirrel in all but a few pockets of England. The grey is bigger than the red which helps it survive the winter better but it is as a carrier of a virus, the Squirrel parapoxvirus, that has devastated the reds’ population. The virus causes the disease Squirrel pox to which the grey is immune but is deadly to the red. There have been many unsuccessful attempts, trapping, shooting and poisoning, to eradicate the grey squirrel although none as far as I am aware of in Cliff Rigg Wood. The National Trust has erected over 60 nest boxes in Newton and Cliff Rigg Woods, most with a metal surround to the access hole to deter squirrels from enlarging it in order to predate on the eggs and young chicks. One conservationist advocates the reintroduction of a key predator, the pine marten, to control grey squirrels. He cites studies in Ireland where grey squirrel populations are on the decline due to predation by pine martens. Red squirrels, on the other hand, are lighter and can escape on thinner branches. And because of this threat of predation, the grey squirrel is more nervous reducing the opportunities to feed, resulting the population being thinner and less likely to survive the winter. There was a report on TV a few years ago about a pine marten being spotted in the North York Moors and last year one was finally photographed. It would be good to see a general reintroduction of pine martens elsewhere in the Moors.