THE evidence is all around. A carefully half-felled willow droops into the water, fresh leaves above the surface billowing in the slight breeze. The remains of three saplings, cut near their bases as if with a sculptor's axe, jut up towards the sky.
Across the loch, a collection of interlocked branches conceal a hole dug into the earthy bank. It's a beavers' lodge and the first in the wild in Scotland for around 250 years.
If he hadn't been handed the task of catching a pair of illegal anima
ls at loose in rural Perthshire then you suspect that Edwin Blake would be cheering them on, such is their harmony with their surroundings.
"People think that beavers totally lay waste to the environment but they don't," he insists. "They cut down what they need to survive and build and maintain a lodge."
His ire is reserved for whoever released the animals into the countryside near Bridge of Earn, where they found what to them was an ideal home on a fisheries loch (the exact location is being kept under wraps to stop the public trying to catch the animals). "Frankly, that was just stupidity as well as being illegal. If you are going to release these animals then it has to be part of a properly controlled and monitored experiment. These would be captive animals and it's just not fair to dump them in the countryside."
Blake's normal job is as one of the head keepers at Edinburgh Zoo, but now's he has found himself at the centre of Scotland's first wild beaver hunt for more than two centuries.
The beaver, pursued for its pelt, is believed to been hunted to extinction in Britain by the mid-18th century. Plans to officially reintroduce the largely nocturnal vegetarian to the wild in Scotland have so far foundered because of objections from farmers, despite similar successful projects on mainland Europe.
Although some exist in enclosures on private Highland estates and in the Highland Wildlife Park near Kingussie, releases into the wild are banned. When the Scottish Executive found out earlier this year that a pair had been co-habiting on the Perthshire loch, Blake was called in to trap the animals alive, beginning work on April 2.
For Blake, it meant working for up to 16 hours a day, sometimes until 5am in freezing conditions, finding where the animals came onshore, laying traps and tramping miles of lochside and a nearby riverbank in case they had fanned out from their original hiding place.
With beaver trapping a forgotten art, Blake had to design his own 5ft-long metal mesh cages which he positioned at four sites around the loch where there was clear evidence of flattened vegetation where an animal had crawled out of the water onto dry land.
Around them were the thick willow trees - willow bark is the beaver's favourite food - gnawed to the point where gravity took over and they tumbled into the water. The young branches and leaves at the top had been cleanly severed to provide food. Smaller trees were felled completely to build the beaver's lodge, set in the bank of a tiny, thickly-vegetated island. Harder aspen wood was cut down to make the structure of the lodge stronger. An expert was at work.
But, like both man and other animals, susceptible to temptation. Beavers, it seems, are partial to apples, carrots and turnips and Blake set the bait.
"We floated some out in the loch on string near to where we thought the beavers came ashore so we could tell from the teeth marks what animals we were dealing with. Then we baited the metal traps and covered the floor with natural vegetation. A beaver has sensitive feet and it would have suspected something wrong if it had stepped on to cold metal.
"And you can't expect to trap it straight away," said Blake. "They have to get used to the bait being around."
To his surprise one of the beavers took the bait after a week. A metal arm dropped down when the animal was inside the heavy cage and the rear door slammed shut. "To be honest I wasn't expecting to catch it so quickly," Blake said.
The search for the elusive second beaver goes on. "There have been no new signs of beaver activity since we caught the first one so it may be that it has moved on somewhere else.
"The fishery manager says he saw two beavers in the water so we have to keep looking."
The manager at the time of the first sightings at the end of last summer is 74-year-old Eoin Christie who initially thought vandals were at work. "But when the dogs went straight to a tree to smell it and I noticed the teeth marks I realised it could only be beaver," he said. "It was a surprise because there aren't supposed to be any in the wild."
He sat up through the night with night lenses and spotted the animals emerging from the lodge. "I am convinced I saw two of them," he added.
The first beaver was taken to the Highland Wildlife Park but has since been moved to Edinburgh Zoo. Scientists are still trying to determine its sex and whether it is a European or Canadian beaver, which will determine its final destination. Tayside Police would still like to speak to anyone who knows about a release, either deliberate or accidental.
Christie believes it was deliberate. "I could find no evidence that they had arrived by the river," he said. "They came in through the gate."
If the second animal escapes detection then it might not be alone for too long. Despite plans being rejected for a colony of beavers imported from Norway, in Knapdale Forest in Argyll, Scottish Natural Heritage still wants to eventually reintroduce the animals to the wild in Scotland.
Stuart Brookes, head of conservation for the Scottish Wildlife Trust, one of the main supporters of the rejected plan, said: "Beavers are very much back on the agenda but whether at the original location or at another has yet to be decided. What should not be done however is to release animals without proper monitoring."
Killed for pelt
The animals were hunted to extinction in Scotland, probably by the 17th century, and throughout many parts of Europe, not because they were a major pest or were dangerous but because their soft, thick, waterproof fur was highly prized and very fashionable.
The fur industry was big business and the development of Inverness in the Middle Ages is attributed to its status as a transport and market centre for beaver pelts. With the animal driven to extinction, many 17th century Scots fur trappers took jobs with the Hudson Bay Company in North America, where they got to work on new and plentiful supplies.
Beavers were also highly sought-after for a secretion called castoreum, produced in a gland below the tail and valued for its supposed medicinal properties. Analysis of castoreum revealed that it contains salicylic acid, which is derived from the beaver's diet of willow bark. It is an active ingredient of aspirin.
In some areas, beaver meat was an important part of the diet, with Roman Catholics permitted to eat meat from the beaver's tail and paws as a substitute for fish on a Friday.