As winter approaches, grey squirrels begin to add to their winter nests or dreys. The female squirrel builds a summer drey to house her youngsters and this is usually a rough ball of twigs and leaves lined with straw moss or feathers often in a tree-hollow or sometimes in a fork in the trunk or between high branches.
The squirrels don’t hibernate in the British Isles
But in autumn, the squirrels anticipate the coming winter by boosting the insulation on their dreys in case they need to sleep out a cold snap. They don’t hibernate here in the British Isles, where they are introductions from North America, but will take to their dreys for few days at a time to ride out freezing, windy or damp conditions.
When they emerge, they search for the nuts and other food that they have buried as insurance against severe weather. In winter, some grey squirrels can even produce a litter of youngsters, whose survival is boosted by their parents ability to find food. Raiding of bird-tables is a regular habit and no doubt increases their chances of survival at this precarious time when their favourite large seeds are in short supply.
Not all grey squirrels build dreys in trees
Many will winter around old buildings or in roof-spaces where they can be a nuisance, gnawing electrical cables.
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