Red squirrel amongst lichen-covered branches

Argyll, the Trossachs & Stirling

Defending the Highland Boundary Line to protect north Scotland’s red squirrels

With vast tree canopies and plentiful food supply, the forests of west Scotland are home to healthy numbers of red squirrels. However, grey squirrels spreading northwards from the Central Belt and westwards from Stirlingshire and Perthshire continue to threaten their survival.

These grey squirrels not only out-compete reds, some also carry the deadly squirrelpox virus. If their spread was allowed to continue, Scotland’s red squirrel stronghold in the southern Highlands would be at serious risk.

Complete removal of grey squirrels from the Central Lowlands is not a practical option. The aim here is containment of the grey squirrel population to prevent further inroads being made on Scotland’s core red squirrel populations north of the Highland Boundary Line, where lowland Scotland meets the mountainous north.
Working in partnership with the Loch Lomond and The Trossachs National Park, Saving Scotland’s Red Squirrels has set up a red squirrel protection network of landowners controlling grey squirrels under Scottish Rural Development Programme (SRDP) funding, backed by local volunteers and the project’s own seasonal control staff.

In the future, we may be faced with squirrelpox in the Central Lowlands’ grey squirrel populations and it will be imperative that grey squirrel densities along the Highland Line are kept to a sufficiently low level, ensuring that there is insufficient circulating disease to be readily transmitted to neighbouring red squirrels.

Where red squirrels do succumb locally to the disease, we need to prevent grey squirrels from colonising the vacant habitat, so that it remains available for red squirrels to recolonise once the disease has burnt out.

Evidence from our work in southern Scotland has shown that this approach can be successful in allowing the persistence of red squirrels, whose populations can go on to thrive despite the presence of the squirrelpox disease (including outbreaks of disease in reds).


Achievements to date

Halting the spread of grey squirrels – In recent years we have seen no further spread of grey squirrels northward or westwards in the National Park area.

Red squirrel recovery – Analysis of trapping results has shown early signs of both a decline in grey squirrel numbers and the beginnings of a recovery in red squirrel populations in many areas.

Landowner support – We are helping landowners to access Scottish Rural Development Programme funding to support grey squirrel control. Others are voluntarily supporting the project through our trap-loan scheme.

Volunteer support – Our survey volunteers are helping us monitor changes in red and grey squirrel numbers across Loch Lomond and the Trossachs National Park, and measure the impact our work is having in the region. Other volunteers are supporting vital control work through our trap-loan scheme.

Squirrelpox testing – Since 2012 we have carried out annual blood-sampling of grey squirrels across Tayside to test for squirrelpox antibodies, as part of a national squirrelpox monitoring scheme designed to detect any spread in the disease.


How you can help

  • Help us monitor the situation in Argyll, the Trossachs & Stirling by submitting a squirrel sighting to our website
  • Help prevent the spread of squirrelpox by cleaning your garden feeders regularly
  • Get involved in citizen science by taking part in our spring surveys
  • Take action for red squirrels by joining our trap-loan scheme

Volunteering with Saving Scotland’s Red Squirrels is a fantastic way to connect with nature and support your local area’s special native wildlife. Our volunteers are provided with the training and resources they need to participate.



Landowners in certain areas can control grey squirrels under Forestry Grant Scheme funding, or join the project’s trap-loan scheme. Woodland owners, meanwhile, can adjust the management of their woods to benefit red squirrels. Please contact your local Conservation Officer for more information.


Area Contact

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Conservation Officer