Outdoors: 'They may have a bad rep but stoats and weasels are some of our most charming mammals'

It is a sight many motorists will be familiar with – out from the edge of a grassy verge a sleek sliver of russet flashes across the road. Quick, bold and determined the small sinuous animal is gone in a second, glad to seek refuge in the vegetation on the far side: it is a stoat, or possibly a weasel, a little bundle of nervous energy that seldom stays still long enough to obtain a good view.

But there is one trick that sometimes enables the opportunity to get a decent glimpse of these fascinating little predators. Next time when out for a walk and you see a stoat or a weasel disappearing down a hole or into a crevice in a wall, stop awhile and wait. Stoats and weasels are curious animals and the chances are it will quickly reappear again, standing upright on its back legs to check out the scene.

Or as the Scottish naturalist David Stephen put it: "The weasel that has taken refuge in an old dry-stone wall can hardly wait to get out quickly enough to look at the person he ran away from in the first place."

Stoats and weasels are attractive animals and it is indeed a shame that both have long been associated with evil and skulduggery. The expression "weasel-word" means making a statement that is evasive or misleading and Chaucer used the old analogy of a weasel being "a bad young woman, afflicted by abnormal sexual desires".

The stoat is similarly tarnished; ill-depicted in many fictional works, it is an animal portrayed with cunning at the very heart of its being.

But could there be elements of truth in such guile?

Certainly, there are many stories of stoats mesmerising their victims by enacting a hypnotic "dance", gradually getting closer and closer to a rabbit before rushing in to deliver the final coup de grace.

It is unclear whether this is a deliberate ploy, or perhaps just an unintended consequence of stoats and weasels being naturally playful animals that like to gambol.

Both weasel and stoat are small slender beasts. The weasel is the smaller of the two and one of the easiest ways of telling them apart is the tail, which is longer in the stoat and has a distinctive black tip.

The upper parts of the weasel are a rich russet and the undersides pure white. The stoat is a warmer brown above and creamy white beneath.

Stoats in Scotland often turn white in winter particularly in areas that have persistent snow cover.

The tail tips of such stoats always remains dark, which is well illustrated on the white ermine worn by peers of the realm that are studded with black. It is likely that the black tail tip acts as a means of "predator deflection", so that when a bird of prey swoops onto a stoat, its aim is taken away from the body.

The prey of stoats and weasels ranges from rodents through to animals up to the size of a rabbit. Birds are also taken. But not every battle is won and the weasel in particular can take on more than it can chew. I have seen a weasel corner a large brown rat on a rocky foreshore, only for the rat to turn upon the unfortunate weasel and see it off.

While the stoat is quite happy to deal with a rat or rabbit, the weasel is more of a vole specialist with its slender body enabling it to pursue its quarry down burrows and along runs.

Research in Aberdeenshire found that male weasels spend about half their active time under matted grass and females about 90 per cent, which explains why the animals are so seldom seen.

It is such elusiveness that always makes the sighting of a stoat or weasel so special. Derided over the centuries and synonymous with all things bad, the true natural history is, of course, equally compelling.

This article was first published in The Scotsman, 05 February, 2011