Geographic variation in tree bark species preference of Sciurus carolinensis: do invasive grey squirrels in the United Kingdom have a foodie culture?

The Eastern grey squirrel (Sciurus carolinensis) is native to North America but has been introduced into the United Kingdom, where it causes ecological and economic damage by outcompeting the native red squirrel and targeting economically important timber trees. Several hypotheses have been introduced to explain this phenomenon, but little research has pointed out social learning as a possible mechanism for the spread of the behaviour. The analysis of metadata on damaged tree species proportions shows strong tree species selectivity within populations and difference in tree species preferences across geographically separate populations in the United Kingdom. These results suggest that bark stripping is not purely genetic or environmental, but facilitated and spread by learning, supporting possibilities of cultural behaviour in grey squirrels. Management implications and further research steps are discussed