THE number of wild beavers descended from illegally released animals living on Tayside has soared to as many as three times the number found six years ago, according to a new report.

The study for Scottish Natural Heritage (SNH) says around 430 of the animals are now living in the river catchment. It found that beavers have also now spread into the catchment of the Forth, south of Tayside.

The news prompted one farmers’ leader to say the growth of the beaver population has caused “real and significant agricultural damage” and call for progress in establishing approved ways of controlling them.

READ MORE: Scottish firth goes wild for oysters for first time in 100 years

Beavers first started appearing on Tayside more than 12 years ago and farmers have been angered by damage caused by the animals, and at the lack of prosecutions of those who originally released them.

The latest research found potential problems for landowners with the rodents, which can weigh 25kg and be more than a metre long, at around 160 spots on Tayside.

The problems can range from dams causing flooding to tree felling, collapsed burrows, crop-eating and fence damage. But Environment Secretary Roseanna Cunningham said in November 2016 that rather than being removed, beavers in Scotland were to be given the same protected status as native animals.

Beavers used to be widespread in Scotland until the 16th century when they were wiped out by hunters, and the decision followed a government-backed trial reintroduction in Argyll.

Ecologists say beaver dams are a valuable buffer against flooding, allowing rivers to retain more water in heavy rain, and they have already proved a draw for wildlife tourists. Legislation confirming their new status has yet to be brought forward, and rules on their control have not been established.

The National:

The new study’s figure of about 430 of the animals on Tayside is three times the approximate number found in a 2012 survey. Researchers however caution that both figures are very rough and could be considerably lower or higher, so will only say for sure they have doubled.

Beavers in Tayside now range from as far north as Dunalastair Water, extending out to the River Dochart and River Lyon in the west, to Forfar Loch in the east and down to the River Earn and Loch Earn in the south. In the Forth catchment their range includes Loch Achray in the Trossachs, the River Teith near Callander and the Devon in Clackmannanshire.

The survey detected 72 beaver lodges, 339 burrows, and 86 dams or recently removed dams. Beavers create lodges by burrowing into river and loch banks.

Because the government has not yet brought in the legislation that would make the beavers a native species, they can still be shot by farmers. However, SNH provides landholders with advice and solutions to beaver problems, including deterrent fencing and flood-bank protection.

Adrian Ivory farms at Strathisla near Meigle in the Perthshire lowlands says his land has been plagued by beavers building dams and flooding his fields. He says removing dams costs him up to £5000 a year, and believes the report seriously underestimates the beaver population, which could be as high as 800.

“This is not good news,” he said. “In the past six years there’s been far more damage being created, more bank erosion, more trees coming down, more dams being built, more and more evidence of them causing issues. I have to hire in a digger as the dams are pretty ingeniously made and can’t be shifted by hand.”

Jonnie Hall, director of policy for NFU Scotland, said the report backs farmers’ reports that beaver numbers and their range have increased rapidly. He explained: “Impacts from beavers have to be managed, and we are working closely with SNH to find constructive ways forward,” he said. “What may be seen as a conservation success story has to be set against real and significant agricultural damage.

“Ultimately we need effective management protocols in place and that means testing all practical mitigation measures and making sure that they work effectively to enable beavers to coexist within the farmed landscape, rather than have beavers impose on farmers what they can and can’t do.”

Nick Halfhide, SNH’s director of sustainable growth, said: “By building dams, beavers improve local water quality and help nurture other wildlife, and it’s wonderful that people now have a chance to see these fascinating creatures in their natural habitat. But in some parts of Scotland, beavers can cause problems, particularly in areas with prime agricultural land.”

He said SNH has developed a mitigation scheme – with input groups including NFU Scotland – to ensure farmers can deal with any problems they encounter.

The survey was done for SNH by the University of Exeter. Professor Richard Brazier from the university said: “This information has wide-ranging value for informing policy and management strategies surrounding beaver reintroduction across

Scotland and beyond, maximising our ability to manage the conflicts and maximise the benefits associated with beavers.”

A Scottish Government spokesperson said: “We’ve been quite clear in our intentions to bring forward legislation to give beavers protected species status, and a great deal of work has been carried out – and continues to be carried out – in order to lay the necessary groundwork before the legislation can be introduced. We have carried out a Strategic Environmental Assessment as well as an assessment of impacts on European protected sites. It’s vital that we take the necessary time to agree on the right management system, for example one that works for beavers, farmers and other land managers.”