Rote Eichhörnchen schlagen graue Rivalen im Kampf ums Überleben

Native red squirrels are about to claim a decisive victory in the long-running battle for survival with their invasive grey rivals in one of Scotland’s biggest cities.

A national project set up to reverse the decline of the native creatures has announced that grey squirrels could be completely eradicated from Aberdeen “in the near future”.

Red squirrels had struggled for decades to gain a foothold in the city as thousands of greys maintained an isolated population in the city, the last bastion for the non-native species north of Argyll and Tayside.

Saving Scotland’s Red Squirrels (SSRS), which is led by the Scottish Wildlife Trust, has trapped over 10,000 greys since 2009, but this year there have been only 12 detections in the city, including seven at feeders and five confirmed sightings. None have been trapped in 2024.

Dr Emma Sheehy, SSRS’s eradication scientific lead for northeast Scotland, said: “In Aberdeen, what we have seen over the last four years is a consistent and significant decline in the numbers of grey squirrels trapped, and in the number of detections we have had both in terms of sightings, and hair samples at feeders.

“This is a result of long-term, consistent trapping since 2009, and in more recent years, adapting our methods to become much more targeted in our trapping, as grey squirrel densities in the city declined.

“This year we have had seven grey squirrel detections at feeders, which we think are from just three individuals, out of more than 5,000 feeder checks so far this year.

“We have also had just five sightings, including a young grey squirrel photographed in September, confirming that they are still breeding in at least one area of the city.”

Scotland is home to about 80 per cent of the UK’s red squirrel population, but the native rodents have struggled due to the spread of greys.

First introduced to Britain from North America in the 19th century, greys out-compete red squirrels for resources, and can also carry squirrelpox, a virus that doesn’t harm them but is deadly to reds.

Grey squirrels arrived in Aberdeen in the 1970s and completely replaced the native species before years of control work by SSRS led to a return of reds.

Grey squirrels completely replaced the population of reds in Aberdeen since their arrival in the 1970s, but now their numbers are dwindling

Grey squirrels completely replaced the population of reds in Aberdeen since their arrival in the 1970s, but now their numbers are dwindling

Last month it was announced that a red had been spotted in the Glasgow suburb of Bishopbriggs, a sight has not been seen in Scotland’s central belt for decades.

Earlier in the year it was also revealed that reds are expected to to create a thriving population across the Morvern Peninsula in the Highlands after a release programme in woodland on the Drimnin Estate near the Sound of Mull.

Data suggests that the targeted approach adopted by SSRS in Aberdeen has disrupted both the spatial and the reproductive behaviour of the remaining grey squirrels, with very little evidence of breeding at all last year.

Sheehy said: “How long it will take to achieve complete eradication will depend on our ability to remove the remaining few squirrels.
“Although it may seem counter-intuitive, this late stage of the removal phase is undoubtedly the biggest challenge the team will have faced to date, not least because of the urban/semi-urban environment which we are working in.

“Because of the challenges of detecting grey squirrels at such low densities, public sightings are more important and crucial to our efforts than ever.

“As such, we would highly encourage anybody in Aberdeen City and its surrounds to keep a close eye out, and report all sightings of grey and red squirrels to us.

“This can be done all year round, but we are especially encouraging people to get outside, explore nature, and record squirrel sightings as part of our annual public citizen science campaign — the Great Scottish Squirrel Survey.

“What has been really inspiring for all of us involved in the project in Aberdeen is seeing, in real time, the recovery of the red squirrel into the city’s parks and gardens.”

She added: “In the UK there is a misconception that red squirrels don’t do well in cities, but that is not true at all. Red squirrels are making an extraordinary comeback in Aberdeen city, and will occupy any space once grey squirrels have been successfully removed — and our data backs that up.

“Up to June this year we had 1,600 red squirrel detections at our feeders, which was a whopping 50 per cent of all feeder checks.”
As the project to eradicate the invasive species from Aberdeen enters its final phase, SSRS has called on members of the public to report sightings of both red and grey squirrels as part of the “Great Scottish Squirrel Survey”. The annual citizen-science campaign runs until Sunday.

Brilliant news. Those grey bastards have nothing on our reds. I’m from London, and I remember the first time I saw a red squirrel in Scotland, it was like seeing a mythical creature.