The North American gray squirrel or Sciurus carolinensis has adapted to urban and suburban areas where it is considered a minor annoyance. While they may be indigent to North America, these squirrels are highly invasive in Europe, particularly in the UK. But how do they affect the ecosystem in Great Britain?
The North American Gray Squirrel is considered an invasive species in Britain because it carries a deadly squirrel pox to the local Red Squirrels. The Gray Squirrel also consumes seven times the amount of food as Red Squirrels, squeezing out any survivors of squirrel pox.
What Do Grey Squirrels Look Like?
Grey squirrels have grey fur with red-brown spots, particularly around the face and legs. The species has a long, bushy tail that aids in balance when climbing trees.
The red squirrel is not to be confused with. The color generally distinguishes these species; however, reddish-grey squirrels and greyish-red squirrels appear rarely. Look at the tail if you’re unsure. Red squirrel tails are homogeneous, but grey squirrel tails have several colors, frequently with a white halo around the edge. Greys are also heavier, with an average weight of 550g versus 300g for reds.
Grey squirrels also have double-jointed ankles, allowing their feet to face both forwards and backward, a perfect adaption for tree climbing. (Source: Woodland Trust)
What Do Grey Squirrels Eat?
Grey squirrels primarily consume nuts, acorns, and tree seeds. These will be picked in the autumn and buried underground, ready to be consumed during the winter when food is scarce. Flowers, buds, shoots, pine cones, young birds, and eggs are consumed occasionally.
To prevent their food stashes from being stolen, grey squirrels have been observed pretending to bury nuts to fool other squirrels that may be watching.
Grey squirrels do not hibernate but can be less active in winter when food is scarce. In cold weather, they will curl up and use their bushy tail as a blanket to keep warm. (Source: Woodland Trust)
How Do Grey Squirrels Reproduce?
Grey squirrels are not aggressively territorial and will coexist in close quarters, yet dominating hierarchies can develop. Breeding occurs during the spring and summer. Females can have two litters of three to four young each year if there is enough food.
The young are usually born in a drey, a nest constructed of twigs and branches. Holes in trees can also be utilized for nesting. After around two months, young squirrels will leave the nest and search for solid meals. (Source: Woodland Trust)
Where Can You Find Grey Squirrels?
Grey squirrels, native to North America, were first imported to the United Kingdom in the nineteenth century. Except for the north and western Scotland and several islands, the species has expanded swiftly and is now prevalent throughout the UK. The UK has an estimated 2.7 million grey squirrels, which is growing. (Source: Woodland Trust)