The sight of television pictures of our American friends on the other side of what is euphemistically known as ‘the pond’ alias the North Atlantic, digging themselves out of eight-foot snow-drifts, came as a stark reminder that we in the Northern Hemisphere are now indubitably in winter mode. There were further reminders of that very basic fact of life, at the weekend. At last, temperatures took a sudden tumble, shaking us out of the apathy that has probably seized us all with roses still threatening to burst into flower and November thus far, offering a very gentle introduction to the winter season.
A glance at the Ben the other morning revealed a cloud cap covering its shapely summit. I have a notion that it won’t be long before that cloud cap is replaced by a rather less ethereal dusting – the first snows of the winter - for snow is sure to become a familiar decoration on the Highland’s higher peaks before very long. So, if we needed a reminder that days are indeed palpably getting noticeably shorter and that winter’s advance is inevitable, as so often is the case, America’s shivering may well be replicated here ‘ere long.
The brief sighting of a stoat taking its life in its paws and flying across the road in front of me in a blur of fast moving legs and a veritable streak of reddish brown and cream, reminded me that here is a creature that uses obfuscation during the winter months, in an almost unique way. Like mountain hares and those high-flying members of the grouse family, ptarmigan, stoats, or at least some of them, change their brown and cream coats for white during the winter months. However, influenced by the phenomenon that is global warming, fewer of them are making that drastic change, especially among populations based in Lowland Britain.
In the case of mountain hares and ptarmigan I guess such a radical change is quite easy to understand as both are inclined to dwell in those higher places, where snow is likely to lie for much of the winter. Before science took an interest in such matters, it was widely believed that stoats effected such a change by literally eating snow! Now we are told, apparently on very good authority, that the shortening of daylight hours and to a limited degree, lowering temperatures, trigger this change. In other words, as we might expect, it is not self-induced! The clear advantage for ptarmigan, hares and stoats alike, is that by turning white they are given that extra key element of camouflage in snowy conditions. As is dutifully recorded, the tips of the mountain hare’s ears remain black when the rest of its body turns white as does, more famously perhaps, the tip of the stoat’s tail.
As students of the aristocracy and our judicial system will know, ermine, as the fur of winter white stoats is known, is a much-prized fur with which to decorate the robes of nobles and judges. The white fur of such robes is of course splashed by black spots, which I understand, are derived from those black tail tips! So, their noble lords are adorned with the fur of a very special little animal, for which presumably, the final sacrifice is involuntarily made!
Ptarmigan of course, go through four phases of plumage change each and every year, as befitting a creature, which is virtually exclusively a resident of the extremely high places, seldom seen at altitudes of less than two thousand feet. Their plumage changes with the seasons so that they may remain as anonymous as possible at all times of the year, a key element in their struggle for survival in landscapes frequently haunted by patrolling eagles. Mountain hares however, are little more ambiguous and in terms of range perhaps, a tad more ambitious.
Indeed, a good few years ago, I was startled, one winter’s day, to put up such an animal whilst walking across a nearby moss – a wilderness in many ways as wild as any mountain top but located at or around sea level! In that case, the advantage of turning white had been turned on its head for in its brilliant white coat, it stood out like a sore thumb in that soggy, green wilderness! This Lowland dwelling colony of mountain hares may seem to be particularly incongruous in an area where the snow seldom lies and their origins there seem to be something of a mystery. They may perhaps have been introduced to this marshy landscape although equally, they may somehow have found their way on to its heather strewn acres quite naturally, albeit that as far as I know, they have now disappeared from these Lowland acres altogether.
I observe that my sightings of stoats and their smaller cousins, weasels, have become increasingly rare, not quite surprisingly perhaps, for they have long been classified by gamekeepers as ‘vermin’ and as such are therefore shown little or no mercy, often shot on sight. Yet, fluctuations in populations of animals usually have an underlying cause. I have also noted in many places now, where once they were prevalent, the likes of kestrels and short-eared owls are now also extremely scarce.
I am therefore led to the conclusion that populations of small mammals, upon which not only stoats but owls and kestrels too rely, are in decline. There have been mutterings about the possible toxicity of modern seed dressings and as many rodents are eager consumers of seeds, they must naturally be very vulnerable to such contamination. However, in the case of stoats, the disappearance from this and many other areas, of rabbits may also have had a considerable effect. Stoats are renowned for their ruthless pursuit and slaughter of rabbits and theirs is a story therefore, that always tells of David overcoming Goliath!
If the effects of global warming are manifesting themselves through fewer stoats becoming ermine then the same can perhaps be said of the mountain or blue hare. I well remember seeing in this airt on a single day, an all-white stoat, a piebald animal and one with no vestiges of white fur at all. Mountain hares too vary to such an extent that once upon a time it was firmly believed that the British landscape supported three kinds of hare, the brown hare, the slightly smaller mountain hare and the ‘variable’ hare. The latter might of course, be likened to the aforementioned piebald stoat, an animal which had apparently stopped its transition halfway between its ‘blue’ summer coat and its new winter white pelage.
Perhaps, as our world gets progressively warmer, the ‘variable’ hare is about to make a re-appearance?