Red squirrel

Red squirrels (Sciurus vulgaris) are primarily threatened by interaction with grey squirrels, which are an invasive non-native competitor species introduced from North America. In addition, interaction between the two species carries the risk of disease transmission, with some grey squirrels carrying the squirrel pox virus. Harmless to greys, squirrel pox has a 90-95% mortality rate in red squirrels, with individuals usually dying within 2 weeks of exposure. 

Red squirrels have been replaced throughout much of their native range since grey squirrels were introduced to the UK in the 19th century. Scotland is now the last major refuge for this iconic species, home to approximately 80% of the remaining population. Within Scotland, red squirrel conservation is largely overseen by the Saving Scotland’s Red Squirrels (SSRS) partnership, supported by the Scottish Government’s Nature Restoration Fund, who lead on the 2015-25 Scottish Strategy for Red Squirrel Conservation.

SSRS currently operates in three key priority areas, one of which is Aberdeen, where an isolated ‘island’ grey squirrel population became established in the 1970s and rapidly spread outward from the city. Since 2009 SSRS has reduced grey squirrel densities and distributions significantly. The work to date has been very successful with the return of red squirrels to gardens and parks within the city, and SSRS is now aiming to completely eradicate grey squirrels from the north east of Scotland.

The RZSS WildGenes team is working with SSRS to develop tools that can use genetic data from hair samples to identify individual grey squirrels and get a better estimate of the overall population remaining in Aberdeen city. This will allow SSRS to improve its population monitoring and make better informed management decisions in a challenging urban environment, assisting in the continued recovery of local native red squirrel populations.