The red squirrel is a true emblem of the Scottish countryside. To catch a glimpse of fiery red fur flickering up a tree and out of sight is a rare treat for most of us. There are only 140,000 red squirrels left in the UK, and more than 75% of these reside in Scotland. Their decline has been driven both by habitat loss and the introduction of the invasive non-native grey squirrel from North America. Grey squirrels outcompete reds for food and nesting sites, and spread squirrelpox, a virus which greys are immune to but which is deadly to reds. When greys move into a red squirrel territory, left unchecked, they can overthrow the native red population within 15 years.
Can we save Scotland’s red squirrels?
The grey squirrel exerts such pressure on the red squirrel that, if the current situation was left to play out, there would not be much hope for the native red in Scotland. The UK’s core red squirrel population in the Scottish Highlands is threatened by the expanding grey-only population in the Central Belt, and the remaining reds in South Scotland are consistently challenged by the influx of greys from Northern England.
Fortunately, there has long been abundant support for the red squirrel’s cause here in Scotland. Saving Scotland’s Red Squirrels (SSRS) was formed in 2009 by the Scottish Wildlife Trust and partners (the current partnership includes NatureScot; Forestry and Land Scotland; Scottish Forestry; Scottish Land and Estates; and RSPB Scotland; with funding from the National Lottery Heritage Fund; Loch Lomond and the Trossachs National Park Authority; and Aberdeen City Council). The establishment of this successful project brought together volunteer efforts from around the country and installed a coordinated, strategic approach to grey squirrel control on a landscape scale.
Now, 14 years on, grey squirrel control officers, with support from a dedicated network of volunteer monitors and trappers and grant-funded landowners, continue to work in priority areas, where the incursion of greys most threatens core red squirrel populations. Through this coordinated effort, SSRS demonstrates that it is possible to halt the regional decline of red squirrels and allow them to expand into new areas with targeted grey squirrel control.
So why not just let grey squirrels replace reds to fill the squirrel niche in Scotland?
Aside from wanting to save one of the nation’s most loved mammals for future generations to enjoy, there are other reasons to keep grey squirrel numbers under control. Unhindered, grey squirrel populations can reach densities eight or more times those of red squirrels. This is much more squirrel action than our native broadleaved woodlands can withstand, and it is at these densities that bark stripping becomes a real problem. Indeed, gangs of grey squirrels have been known to decimate whole woodlands! In England, where the majority of woodland cover is broadleaved, and where grey squirrel densities are much higher than they are in Scotland, tree damage costs the forestry sector an estimated £31 million annually.
Thanks partly to the grey squirrel’s preference for broadleaves, and partly to the work of SSRS, the conifer-dominated Scottish forestry sector is not yet feeling quite so nibbled. The Scottish Government, however, through its statutory forestry agencies, and in partnership with environmental NGOs, is actively engaged in landscape-wide native woodland restoration programs that will likely increase our national share of broadleaves. Initiatives such as Riverwoods – reconnecting the riparian habitat along our waterways, and the Alliance for Scotland’s Rainforest – revitalising the rare and important temperate rainforest ecosystem of the West Coast, could be put at risk by an unchecked grey squirrel population in Scotland.
What is next for SSRS?
Luckily, the SSRS program is a tried and tested approach already in place for keeping grey squirrel numbers down and stopping their spread into new areas. However, the program is now coming to the end of its latest round of funding and is in a Transition Phase. The Final Report from SSRS’ last major project phase (Developing Community Action) was released last month with a clear overarching recommendation that centrally coordinated, professional grey squirrel control and monitoring should be continued in the priority areas long-term to ensure a future for the red squirrel in Scotland. It is, however, no longer sustainable for this work to be delivered on short-term funding cycles with a charity responsible for leading delivery.
The draft Scottish Biodiversity Strategy to 2045 provides scope for invasive grey squirrel management to be continued as part of the Government’s plan for its delivery. Continuing this work would align with the Strategy’s commitments to continue effective species recovery programs, tackle invasive non-native species, and enhance forest and woodland biodiversity.
The re-shaping of SSRS therefore provides an opportunity for the Government, through its statutory agencies and other public bodies, to follow through on its biodiversity commitments by adopting a blueprint, developed over the lifetime of the project, to sustainably deliver a coordinated landscape-scale mosaic of grey squirrel control. Doing so will not only ensure the future of the iconic red squirrel in Scotland, but will also serve to protect our vulnerable existing and restored native woodland ecosystems and the vast assemblages of life that they have the potential to support.
Guest blog by Hazel Forrest, Species Advocacy Officer at the Scottish Wildlife Trust, May 2023.