Assessing grey squirrel dispersal patterns within the landscape using sequence variation

The grey squirrel Sciurus carolinensis is thought to have contributed to the decline of red squirrel S. vulgaris populations in the UK through resource competition and disease spread. This study used mtDNA sequencing to assess patterns of grey squirrel dispersal in the UK. Patterns of genetic variation within the dloop sequence were characterised for seven grey squirrel populations. Infiltration directions and potential barriers to dispersal are identified and discussed, with a focus on Cumbria, a county at the forefront of grey squirrel expansion. Understanding the dynamics of grey squirrel dispersal will aid their management at a landscape scale and enhance the conservation of red squirrels.