I always like to get out for a wander at lunchtime during work if the weather is nice, and today was a really pleasant wintery day – chilly, but with blue skies and sunshine. The local mountain of Ben Ledi had a cap of snow and glistened under the afternoon sun.

I went for an uphill walk to get myself warmed up, and chose to walk up through the Callander Crag’s woods. It’s a nice steep stretch of woodland path under largely oak and beech trees, and climbs the hillside above Callander. With more time, you can follow it on to reach the start of mountain paths or visit Bracklinn Falls.

Normally the Crags woodland is a great spot to see red squirrel, but today was unusual in that I spotted the grey equivalent. Now I’m fully aware that the grey squirrel is much maligned, but I admit to having a soft spot for these unwanted immigrants – I did have a pet squirrel in my teenage years. This one was especially curious and followed me for a short while, tail flicking irritably all the while.

I’ve also written before about creatures that are unloved and unwanted, but can’t help feel that the poor grey is particularly despised. Grey’s, of course, were introduced into the UK around a century ago and have been assigned a reputation for “chasing away” or aggressively displacing the indigenous (and arguably cuter) red squirrel. This is not true – grey squirrels are not belligerent, and do not “bully” the greys out of their territory. It is more a matter of how adaptable the greys are compared to the reds. The Red Squirrel Survival Trust supports this, and provides alternative explanations as to why the spread of grey squirrels remains a threat, and why their spread seems relatively confined.

“Red and grey squirrels eat the same types of tree seed including oak acorns. Interestingly, dietary studies have revealed that grey squirrels are better able to extract the proteins and energy stored in acorns than are red squirrels. Where oak is present in a landscape it therefore gives grey squirrels a competitive advantage. Grey squirrels are almost twice the weight of red squirrels and consequently require more energy per day. In upland spruce forests where tree seeds are so small that grey squirrels find it difficult to eat enough to satisfy their basic energy needs the smaller red squirrel is better able to survive.  These respective facts help explain why regionally where grey squirrels are present, red squirrels persist for longest in coniferous stands.”

There is more about the impact of grey squirrels versus reds here. It is interesting to read more about this subject alongside research into the fortunes of the pine marten. Studies have shown that, despite being a main predator of red squirrels, increasing pine marten numbers leads to an increase in red squirrel numbers where greys are also present. It has been suggested that pine marten find it easier to prey on greys (which are heavier, larger, and tend to spend more time foraging on the ground than reds). This is great news for reds, who are then able to re-colonise areas where they have been usurped.

In the meantime, I’ll continue to admire the arboreal acrobatics both species.