IN THE north east of Clackmannanshire, from Tillicoultry through to Dollar and Muckhart, and then down to Forestmill, red squirrels are thriving.

When I first moved to this part of the Wee County about 14 years ago, red and grey squirrels were present in roughly equal numbers, but now the reds predominate, and the greys have declined.

I reckon the reason for this is because pine martens have moved into the area.

Until the 19th Century pine martens were widespread in Scotland, but relentless persecution by gamekeepers and high demand for their luxuriant soft pelts soon saw the population plummet.

By the early 1900s the pine marten was only holding out in remote areas of the north west Highlands.

But since the Second World War there has been a remarkable turnaround in fortunes, with afforestation and a more enlightened attitude to their presence helping to fuel a quite remarkable recovery.

Now, I often see pine marten signs in the north east of Clackmannanshire, most usually their droppings deposited on rocks or tree stumps.

My trail cameras also sometimes catch them on video, including the freeze-frames shown here, taken recently near Dollar.

Pine martens are proficient climbers and powerful enough to take both grey and red squirrels.

However, the smaller red is so agile that in most instances it can usually dodge a pine marten by fleeing to flimsy branches on the very edge of the tree canopy before leaping over to the next tree.

Interesting recent research has also shown that red squirrels are better at detecting pine marten scent than greys and are better able to avoid them.

For a pine marten, the less nimble grey is much easier to catch, especially since it spends much more of its time on the ground than the red.

Thus, the corresponding reduction in grey squirrels has benefited the reds in terms of reduced competition.

Grey squirrels still predominate in the rest of Clackmannanshire, including around Alloa.

I suspect this will always remain the case, as the more open landscape, combined with suburban parklands, are ideal for greys, and not the kind of place where pine martens might haunt.