But for one local population of Scottish red squirrels, the extra risk of becoming roadkill is now less of a worry.
Conservationists are celebrating after a specially designed “squirrel bridge”, slung between trees high above a road in the north west Highlands, proved to be a resounding success.
Camera traps hidden on the rope bridge, which is suspended over the A896 near the village of Shieldaig in Wester Ross, have revealed that it is now something of a busy thoroughfare for reds.
The crossing was installed last June by conservation charity Trees for Life as part of an ongoing project to reintroduce red squirrels to the area, where they were once common.
Only 120,000 red squirrels are currently estimated to survive in Scotland, due to the widespread destruction of their forest habitats and the introduction of the grey squirrel to the UK in the nineteenth century.
As well as outcompeting reds, grey squirrels are also carriers of the squirrel pox virus, to which they are immune but which is lethal to reds.
To help them fight back, Trees for Life has been relocating small populations from their current strongholds in Inverness-shire and Moray to suitable forests in the north west Highlands. The project has seen 140 red squirrels released so far, including in the Ben Shieldaig woodland, one of Scotland’s few remaining fragments of ancient Caledonian Forest.
Becky Priestley, Trees for Life’s wildlife officer, told The Scotsman the team were not sure whether the squirrels would take to the bridge.
“I was delighted when I got down the camera traps and saw the photos,” she said. “As we were taking down the cameras, a red squirrel shot up one of the trees that the bridge was tied to, and I could see that she’d built a drey [nest] up there – that suggests there’s regular use of it.”
Together with road signs alerting drivers to the squirrels’ presence, the rope bridge appears to have had a significant impact in reducing road deaths.
Since the two innovations were installed there has only been one known red squirrel road death in the area, with none reported so far this year. In the year before the measures were introduced, there were three reported road deaths of reds in the area and two others further away.
According to the group Saving Scotland’s Red Squirrels, around 3 per cent of sightings recorded through its website are animals spotted dead on roads, with the figure potentially far higher.