Beavering away
Long extinct in Britain – and yet the iron-toothed rodents that reshape landscapes are back. Can you find them?
HERE ARE SIX incredible things about beavers. They are the second-largest rodents on Earth, outweighed only by the capybara. Their teeth are coloured rust-red by iron, which gives them the strength to gnaw down trees. A secretion from sacs near their anus is used to flavour ice-cream. They can hold their breath underwater for 15 minutes. The Catholic church used to classify them as fish, which permitted people to eat them on Fridays. The Eurasian beaver is native to Britain but has been extinct here for almost 500 years.
Or I should say the Eurasian beaver was extinct here for almost 500 years. I’m walking in a forest in the west of Scotland, out on the fringe of Argyll where long lines of land and loch lie in parallel streaks. A tree at the side of the path looks like it’s been attacked by a pencil sharpener, its slim trunk chiselled to a point about a foot off the ground. Look closely and it seems the cuts were made by teeth. This was felled by a Castor fiber.
Beavers were officially reintroduced to Britain here at Knapdale Forest in 2009, at the start of a five-year Scottish Beaver Trial. Three families were released: one into Loch Linne, one onto Creag Mhor Loch and one into Loch Coille-Bharr – where
I’m headed. All the animals came from Norway’s Telemark region and, after testing and quarantine, they swam out into a landscape that looked very similar to the one they knew in Scandinavia, with its wooded hills and shining lakes.
This wasn’t the first attempt to return the longgone mammal to these shores. In the 1870s the 3rd Marquess of Bute and richest man in the world, John Patrick Crichton-Stuart, walled in four acres of pine forest on the Isle of Bute and released a quartet of beavers into a stream running through it. He didn’t seem much fussed about sticking with native fauna: these were the North American species (Castor canadensis), sold to him by Charles Jamrach, ‘Dealer in birds, Waterfowls, Animals, Birdskins, Shells’. Jamrach also provided him with wallabies and offered him a couple of sloth bears for his Scottish island. Meanwhile down in Suffolk, beavers were brought to Sotterley Park, but when they built a dam it was deemed an ‘eyesore’ and destroyed. Two of the hapless rodents ended up stuffed, in Lady Gooch’s living room.
The ‘eyesore’ verdict feeds into a widespread perception that beavers are destructive creatures. It does look that way as I hit the shore of Dubh Loch. Dead trees lie scattered around the ragged-edged pool, the base of their trunks showing telltale gnaw marks. Some stumps are still standing, but clearly scarred by teeth, while the roots of other trees are drowning beneath the rising water.
There is creation in this devastation, though. The beavers’ tree felling around the dark loch is a natural form of coppicing, allowing sunlight to hit the forest floor and nourish the next generation of saplings and scrub. The dams they build create deep pools and wetlands that help water voles and shrews, otters, trout, salmon and dragonflies to flourish. Their industry can also help us by slowing the flow rushing down rivers – holding water back in droughts, easing flooding in wet weather, and reducing sediment movement downstream. In fact, the beaver is defined as a keystone species for its critical role in shaping its local ecosystem.
And they are supremely talented engineers.
“A tree by the side of the path looks like it’s been attacked by a pencil sharpener, its slim trunk chiselled to a point.”
JUST THE TWO OF US
I walk on through twisted oak woodland to the mile-long lagoon of Loch Coille-Bharr, and spot a big heap of wood half-in, half-out the water. It looks like someone has recently abandoned an outsize game of pick-up sticks, but it’s a beaver lodge where a pair – monogamous for life – will raise their kits. Crafted wattle-and-daub style from trunks, branches and mud, these structures can reach the size of a garage. Inside there are often multiple chambers, snug above the loch-line. To keep predators out, the only entrances are underwater.
Then there are the structures for which beavers are most famous: dams. The largest yet discovered in the world stretches 2788 ft through the Alberta wilderness in Canada, and it’s thought to be the work of generations of North American beavers starting in the mid 1970s. Every last dam is an astonishing feat of engineering. Often the foundations are built from rocks, boulders, even unearthed bricks. Trees are felled and dragged into place. The wall is packed with mud and strengthened by the natural accumulation of sediment on the dam’s upstream side. Once it’s built, the furry architects are solicitous in their maintenance, listening for the tell-tale splash of breaching water and repairing swiftly.
I stop for a closer look at a felled tree, where a beaver has chewed through the trunk like we’d munch through an apple. Their distinctive ironclad buck-teeth never stop growing and they are chainsaw effective – able to chop down a small tree in minutes – but the work involved in building a dam is immense. Why do they do it?
These amphibious creatures are much safer in water than on land, and the dams deepen pools and rivers so they can swim more easily. Beavers also dig channels in the muddy depths to extend their range through shallower areas, and down below the surface you might spot branches waving like a subaquatic forest. It’s a larder of food stashed away for winter – one they can reach from their lodge even if the surface of the loch freezes over. Despite popular myth, and the misleading characters of Mr and Mrs Beaver in CS Lewis’s Chronicles of Narnia, beavers don’t eat fish, but are vegetarians who feast on grass, leaves, twigs and bark. Birch, alder, rowan and willow trees are all favourites.
From the pontoon on Loch Coille-Barr I can see a dam heaping up among the trees to my left, built by the beavers to expand Dubh Loch. I’ve not seen so much as a telltale ripple of one on the move though, or heard the alarm whack of a tail on the water. It’s a relaxing place to be on a summer afternoon, lulled by a gentle ripple, but odds of a sighting improve if you walk at dawn or dusk when these crepuscular creatures are most active.
What a sight it would be. Eurasian beavers are burly animals that can grow to over three feet long with a scaly, paddle-shaped tail adding another foot or more. Weight can top 66 lbs – that’s seven times your average pet moggy – and their fur varies in colour from light rust to almost black. Its aquatic adaptations would make a scuba diver envious: the teeth are backed by chunky cheek pads that close up to let the beaver gnaw underwater without
gargling; its hind feet are webbed; its nostrils, ears and transparent third eyelids all close underwater; and its flat tail is an excellent rudder.
I follow the path round the south tip of the loch, past nibbled stumps, stripped branches, and heaping woodchips, and wonder what Britain would have looked like when this was normal, not an extraordinary rarity.
It was two things in particular that saw the beaver hunted to national extinction: its fur and its musk. 1000 years ago their pelts fetched 120 pence a piece – five times that of a wolf and 15 times an otter. It was prized both as fur, and later for felt made from its dense, barbed undercoat. Many a top hat was fashioned from beaver, as was Napoleon’s signature bicorne chapeau.
ON THE NOSE
The musk, technically known as castoreum, is a molasses-like substance used by beavers to mark their territory. Humans liked its leathery, vanilla scent too and it became popular in perfume and as a flavouring for food. It’s still in use today, albeit more rarely, including in a Swedish schnapps called Bäverhojt (beaver shout). Quick warning here – those of a delicate disposition may want to skip the next couple of paragraphs.
The musk is produced in castor sacs which are separate but very close to the anal glands and, apparently, it is possible to ‘milk’ them for castoreum. It is simpler to kill the animal though, and that’s what most hunters did. For centuries there was a myth that a beaver would gnaw off its own testicles (the testes are internal, so these are actually small bumps connected to the castor sacs) and throw this treasure at pursuing hunters in an attempt to escape with its life. Aesop included The Beaver and his Testicles in his famous collection of fables, asserting the following moral: ‘If only people would take the same approach and agree to be deprived of their possessions in order to live life free of danger; no-one, after all, would set a trap for someone already stripped to the skin.’
And while we’re talking genitalia, beaver is of course a euphemism for a woman’s pubic area. Most dictionaries suggest it derives from the use of beaver as a slang term for a beard, but another theory says it comes from a group of prostitutes who shaved in an effort to prevent the spread of venereal disease. When their clients didn’t like the bare look, they took to wearing pubic wigs
– or merkins – made from beaver fur.
The path leads on round the loch’s wooded shore, the foliage and ferns forming a lush green world. It’s thought the last beaver in Britain was killed in the 16th century – the last known reference to them in the wild in England was in 1526 – and they were persecuted right across Europe. By the turn of the 20th century, only about 1200 animals survived in the world; now, thanks to widespread reintroduction there are estimated to be 1.2 million.
The success hasn’t come easily though. Some of the beavers brought to Knapdale died or vanished without a trace. There was, and still is, resistance to their return to Britain. Farmers worry about land being flooded and crops damaged, anglers are concerned about the impact on fish populations, and there’s an argument that the countryside
has simply changed too much to have them back.
But they are back, and not just here at Knapdale. A population thrives on the River Tay. Nobody knows how they got there, but they’re thought to number in their hundreds across the basin. Down in Devon, in an awkward taxonomic clash, they have appeared on the River Otter. Again, nobody is sure of their origin, but as anyone who saw this year’s Springwatch will know, they have been welcomed by locals, both as amazing creatures but also for the help they provide in flood prevention.
The project here at Knapdale was the first formal reintroduction of a wild mammal in Britain. The trial was a success, more beavers have been brought in to reinforce the population, and the animal is now a protected species in Scotland. As I walk back through a tall stand of trees I wonder if one day other animals we have hunted to extinction will return. Will we see lynx stalk through a forest like this? Will we hear the spinetingle howl of a wolf from the hills above?