Conservation projects, such as Saving Scotland Red Squirrels, work best when on the ground action is backed up by policies offering long term support. This Invasive Non-Native Species (INNS) Week, we heard from the Scottish Wildlife Trust’s policy team about the current status of red squirrels, and what we need from Scottish Government to secure the future of this iconic species.
The red squirrel is one of Scotland’s most iconic native mammals and the only squirrel species to have evolved with Britain’s native woodlands. They are a much-loved native species, deeply rooted in Scottish folklore and history, and continue to inspire public affection across the country. Red squirrels also play a vital ecological role in promoting natural forest regeneration by storing tree seeds in the ground (many of which later germinate into new seedlings) and dispersing the spores of symbiotic mycorrhizal fungi that provide disease resistance to trees. However, red squirrels have experienced severe declines across the UK and active conservation efforts are crucial to supporting the recovery of their populations.
Image: Perthshire red squirrel on a log © Raymond Leinster
Current Situation – Species status in Scotland
Red squirrel populations in the UK have suffered critical declines of approximately 90% over the last 150 years. Historically, populations were estimated to have reached a high of 3.5 million, occupying woodland across the whole of the UK. Today, their range is largely restricted to Scotland and Northern England with an estimated population of just 287,000, with Scotland supporting 83% of the UK population. This population decline has been largely driven by the invasion of invasive non-native grey squirrels, which outcompete red squirrels for habitat and transmit the highly deadly squirrelpox virus. Once they have invaded an area, grey squirrels can entirely replace red populations within 15 years. Habitat fragmentation also severely restricts red squirrels, confining populations to isolated pockets of forest and restricting movement and population expansion.
Currently, Scotland’s red squirrel populations are stable, although with notable increases in areas of conservation action such as Aberdeenshire. Although current populations are severely constricted in range, even maintaining this reduced population has been hard-won and only achieved through decades of dedicated conservation, including by Saving Scotland’s Red Squirrels (SSRS). NatureScot’s primary action to support red squirrel conservation has been in partnering with SSRS, as stated in Scotland’s Strategy for Red Squirrel Conservation. The SSRS project controls grey squirrels in several large priority areas in the south of Scotland and Aberdeenshire and maintains a coast-to-coast control line along the Highland Boundary Fault (Figure 1). This Highland Line control area keeps grey squirrel populations restricted to the south of the line, making the highlands a grey squirrel free zone (with the exception of Aberdeenshire, where a more recent, isolated release is currently being managed). Over time, the project aims to continue moving this line southwards where a shorter area coast-coast makes control more feasible. Once this has been achieved, northern Scotland could be maintained as a permanent grey-squirrel exclusion zone with minimal costs through continual monitoring of the reduced control area and rapid responses to any grey squirrel incursions.
Figure 1. Map of Scotland showing SSRS priority control areas, including the coast-coast control line across the highland boundary fault.
Going forward – Policy asks
While SSRS has made significant progress, the project currently relies on short-term, volatile funding cycles (typically around two years), which severely constrains long-term planning and management. SSRS cannot guarantee funding from one cycle to the next, and without continued momentum, grey squirrels have the potential to rapidly recolonise, undoing decades of progress. Additionally, Scottish Government has not taken direct strategic ownership of grey squirrel control, placing disproportionate reliance on SSRS which is a non-government charity organisation. Encouragingly, the recently published Scottish Action Plan for Invasive Non-Native Species 2026-2032 identifies grey squirrel control as a long-term key strategic priority and also recognises the need for a step-change in investment in INNS control more broadly, including the development of more sustainable, long-term financing models.
NatureScot’s current Scotland Strategy for Red Squirrel Conservation (2015–2025) is now expired, and a new national strategy is urgently needed to maintain momentum. This new strategy is the key mechanism through which government commitments in the INNS Action Plan must be translated into practical delivery and on-the-ground action, including: greater governmental input alongside SSRS’s initiatives, specific plans for government-led support and policy mechanisms, and long-term funding commitments for grey squirrel control.
Priority policy actions:
- Increase and secure long-term funding for SSRS to allow the programme to plan beyond short-term cycles and to establish long-term systems for grey squirrel monitoring and management, in line with the recommendations of the INNS Finance Summit on developing more stable and sustainable financing models for INNS control
- Government should take strategic ownership of invasive species management, embedding it within the operations of statutory agencies, local authorities, and landowners.
- Ensure statutory forestry agencies are resourced to embed red squirrel conservation and grey squirrel control into their core operations.
- Update the Forestry Grant Scheme to better support private landowners in delivering grey squirrel control aligned with landscape-scale conservation goals.