The news from the beaver colony is mixed. We learned from Scottish Natural Heritage (SNH) recently that the beavers at Knapdale in Argyll are happily chewing their way through 10 per cent of the trees around their ponds. But life for the five beaver families has not been easy this last two years. Of the 16 original settlers, three have died and three more are missing presumed dead. Surprisingly, given their unpopularity in the area, there appear to be no suspicious circumstances.
The SNH study finds that “the beavers are changing the woodland structure but so far they have had little effect on fish in streams”. This should reassure the anglers, just one of the human species which object to the re-introduction of the European beaver to Scotland.
It is not that beavers eat fish – they are strictly vegetarian – it is just that their damn dams prevent fish from swimming upriver to lay their eggs. On the other hand, the ponds and wetlands created by the beavers are providing new homes for frogs, toads, water voles, dragonflies and several species of birds. The felled trees, young willow and rowan mostly, are also re-shooting quickly and producing a nicely coppiced woodland.
Meanwhile, SNH has been trying to catch a number of mixed-race beavers who have been squatting illegally in the woods in Tayside. But there has been limited success: of the estimated 80 asylum seekers, only one has been arrested.
And this rather awkward balancing act over Scotland’s biodiversity is being repeated with other species. There are the famous hedgehogs of the Uists, where £1m was spent removing the invaders but bird numbers continued to decline. In Orkney, they are trying to do the same thing with white-settler stoats. In the fight against the American grey squirrel, a line has been drawn in the sands of Perthshire beyond which the pox carriers shall not pass.
On the plant front, I have spent many an unhappy hour this year pulling out Himalayan balsam on my local nature reserve at Duddingston. It is a nice enough pink flower – called “kiss-me-on-the-mountain” by the hopelessly romantic Victorians who introduced it – but it has a nasty blood-red root which can cling to the slightest suggestion of soil and it simply strangles and swamps all native plants. The Victorians can be blamed, too, for the other triffids: Japanese knotweed, giant hogweed and the all-conquering rhododendron.
But it is not just the invaders who caused us to miss our biodiversity target for 2010. We ourselves have not being doing much to help. The Caledonian forest has been cut down and replaced with Norwegian sitka, peatlands have been drained, farmers no longer do meadows and hedgerows, bracken has been allowed to take over whole hillsides, and we have tarmaced acres of land for roads and car parks. We have virtually fished out the sea and have been filling the atmosphere with carbon which has caused our climate to change, sometimes dramatically.
The result is that 20 per cent of all bird species are in decline. Seabird numbers have dropped by around 40 per cent in the last ten years and freshwater fish by 50 per cent. Three quarters of butterfly species are in decline. Britain has lost three of its 24 species of bumblebee in last 70 years and the Scottish great yellow may be the next to go.
The number of wild mammals has been falling, too. Britain’s 30 million hedgehogs have been reduced to 1.3 million in the last 50 years. The red squirrel population has declined by 50 per cent and we are down to our last 400 wildcats. Over the last few centuries, of course, we have lost our wolves, bears, lynxes and our returning friends, the beavers.
How far the re-introduction programme should go is a moot point. The ospreys, the golden eagles and the white-tailed sea eagles have all been a great success – except among the bird-poisoning fraternity. Tourists have flocked to see the birds. The sea eagles on Mull, for instance, have brought in £8m to the local economy. But the planners are swallowing hard when they hear of Paul Lister’s vision for his Alladale estate north of Inverness, a land of wolves, wild boar, lynx and other megafauna.
There are those who say all this angst about biodiversity is nonsense. Planet Earth, they scream, has always been changing. Heatwaves come and go, ice ages melt, while erosion, volcanoes, earthquakes, meteors and moving tectonic plates all change our landscape and our climate and our flora and fauna. We should relax and let the declining biodiversity rip. Let the puffin and the wildcat disappear and welcome the newcomers like the knotweed and the balsam and the grey squirrel. We are never going to bring back the woolly mammoth or the dinosaur, so let’s not stand in the way of the Earth’s progress.
But such free-marketers are wrong. In fact, it’s unusual for them to take such a long-term view. We might not be able to affect the cooling of the sun or the movement of the continental plates, but man is now a major player in the Earth’s progress. Our industrial age has influenced its development and if we are heading for a less diverse world, we are the ones to blame.
It was us men – mostly men – who shot all the wolves and eagles in the first place. So I, for one, now want to keep as many as possible of the 90,000 species we have left in Scotland. As John Donne would have it, “each one’s death diminishes me”.
And, by the way, SNH’s list of over 1,000 threatened species is not dominated by nice furry mammals or dramatic birds of prey, but by obscure lichens, algae, fungi, flowering plants, beetles, and more than 300 other insects on which the chaps at the top of the Mikado’s list depend, including us. “Therefore never send to know for whom the bell tolls; it tolls for thee.”