They were once the great predators of Scotland - before their habitats were destroyed and they were hunted to extinction in the UK.

But now conservation groups are hoping to bring back the lynx and the wolf to Scotland as part of a controversial process known as rewilding.

Parts of the country have already experienced rewilding, with eagles, red squirrels and beavers already reintroduced, as well as trees and forests being protected and encouraged to grow.

However, calls are mounting to take things further and allow predators back on Scottish soil in a move conservationists claim will help to transform the country’s wildlife.

Steve Micklewright, chief executive of pro-rewilding charity Trees for Life, said: “Despite its raw beauty, the Scottish landscape is today an ecological shadow of its former self.

“It wasn’t so long ago that vibrant, wild forest stretched across much of Scotland, with beavers and cranes at home in extensive wetlands and lynx and wild boar roaming in woodlands.

“Yet now our large carnivores are extinct, our woodlands reduced to small fragments, and a degraded landscape supporting little life stretches across millions of acres. But it doesn’t have to be this way.”

The charity is about to publish a book which it hopes will spark debate about rewilding and offer a vision of how things could be for Scotland’s wildlife.

Scotland: A Rewilding Journey will look at the benefits and pitfalls of reintroducing predators - including addressing concerns over the potential threat to livestock.

Farmers have long opposed rewilding because of this issue, as well as concerns over replacing food production with wilderness.

However, Mr Micklewright believes farmers could look to other countries where wolves exist, such as Romania, for advice on how to protect livestock.

“Our farmers are used to working in a landscape that doesn’t have these predators and so they don’t need to think about it,” he said.

“Wolves were last seen in Scotland in the 1700s and lynx, in the late middle-ages, so they’ve never had to deal with it.

“But in other countries, it means that farmers have to look after their animals differently. In Romania, for example, they use a big dog to scare the wolves off.

“Obviously farmers feel that they have the most to lose from rewilding, and no-one wants to risk anyone’s livelihood, so we need to look at how we address that and how we might compensate for that.”

The charity boss claims that the book, which will be published in Autumn, is honest and addresses the potential pitfalls of rewilding, but also focuses on the opportunities for Scotland - particularly the tourism industry.

He said: “People might think that rewilding means creating a wilderness where people don’t go, but that’s not the case.

“We believe we would have more people living in the Highlands if we did this, not less, and we’d have more jobs, not less, because people would want to see and experience it.

“There’s a big opportunity here for Scotland to become a world class environment that people want to come and visit.”

Mr Micklewright believes the Highlands could become the Scottish equivalent of Yellowstone National Park in the US - where rewilding, despite some difficulties, has proven to be a success and regularly draws millions of visitors to the site each year.

Wolves were reintroduced to the park in 1995 and have been credited with increasing beaver populations and bringing back aspen trees and vegetation.

Trees for Life is already being recognised for the work it has done on Dundreggan estate in the Highlands, which was being overgrazed by deer and sheep.

The charity is reforesting the area and by 2058, expects to see red squirrels, beavers and wild boars return to the area.

However, Mr Micklewright claims reintroducing wolves in the Highlands is still a long way off.

“Wolves and lynx are already making a comeback in other parts of Europe, but - obviously - they can’t get to Scotland unless we decide to bring these animals back.

“We’re a bit scared of that idea. When it comes to the bigger predators, that’s still a big, scary thing for a lot of people.

“I doubt that wolves will be reintroduced in my lifetime, but I’m hopeful that the lynx is more of a possibility.

“The actual practicalities of reintroducing the animals is not the difficult part in all of this - it’s the social stuff, the conversations that need to be had, that’s the hard part.

“We need to start conversations with politicians, with farmers and landowners - we need to have a national debate about rewilding.

“And hopefully the book will help to start that process.”

Trees for Life has launched a crowdfunding appeal to help fund the publication of Scotland: A Rewilding Journey. Anyone interested in donating can do so at crowdfunder.co.uk/rewilding.