Wanted: nature's messenger, (must have own armour)

Often only a handful of people turn up for the fortnightly chats over a cup of tea/coffee and biscuits, but they were his idea and he values them.

However on Barra over 200 attended. Not all best pleased that SNH has recommended to ministers that the Sound of Barra be designated as a Special Area of Conservation (SAC). It was the subject of fierce opposition from local fishermen.

Mr Thin says he understood. "If you are a creel fisherman on Barra and somebody tells you your livelihood is at risk , of course you are going to be upset."

According to ministers the management of the Barra SAC is to be led by the community to protect local interests. But for years now it has been SNH who have felt the wrath of islanders.

Mr Thin makes clear SNH is only ever the messenger. "The UK Government signed up to the European Habitats Directive . It requires the designation of various particular habitat sites including sandbanks and reefs.

"So we were asked by the Scottish Government where they were round Scotland. We advised about those in the Sound of Barra. That was our job."

But the public perception persists that SNH intervenes frequently to stop important local developments - risking precious jobs to protect a black throated diver, an alpine shrub or a particularly rare fungus.

He responds that parliaments make law. "We advise ministers and councillors on aspects of these laws. If somebody doesn't like the implications , they often blame us.

"But we have no democratic mandate, no regulatory powers over development. Elected politicians always decide"

This requires him to steer SNH on a middle course between the likes of wind farm developers and the groups trying to protect wild land; between sporting estates and the conservationists who want to cull deer to allow native woodlands to grow. "What matters is that the public interests of the Scottish people are best served. They are not best served by having no deer at all, and they are not best served by having so many deer that we don't have any native woodland.

"Wild land has a value as a resource for recreation, for health including mental health, and for tourism. It helps underpin the brand value of economically vital products like whisky. But Government is also clear that renewable energy has a public value. Our job is to help ministers find a way through ."

He insists SNH is not just about looking after Scotland's natural environment. "I am absolutely confident SNH looks after nature very well. I am extremely anxious it does so for a clear set of purposes centred on improving the lives of Scotland's people."

For all that, he is a messenger well used to being shot. But there is a quiet steeliness to him and now after seven and a half years - two full terms and a half third term - his time is up. The marksmen will have a new target.

The job, which currently pays £352 a day for approximately 12 days a month, will shortly be advertised by the Scottish Government.

Mr Thin remains evangelical about the importance of Scotland's natural assets from the hills and mountains he climbs and runs, to the wildlife, the people and their culture.

"I would regard it as deeply tragic if Scotland was to squander these assets. They are what sets us apart in the world."

He is convinced the public increasingly appreciate this "Look at serious debate over the persecution of raptors.

"Why are people so worried about golden eagles when most Scots will never see one? They care deeply because they are part of what makes this country special."

SNH has been accused of a spot of persecution itself. He wasn't chairman when it got embroiled in its biggest controversy, the cull of hedgehogs on North Uist.

That began 10 years ago to protect ground nesting birds' eggs, only to be discredited when it was established the spiky ones could survive being moved to the mainland. "I chaired the board meeting when we decided to stop killing the hedgehogs," he adds.

But he is particularly proud about what has been happening on another island. SNH-owned Rum used to be known as the "forbidden island", a place where scientists met visitors on the pier and demanded to know why they had come.

For decades it was like a company town, with the demands of the nature reserve dictating who could live on the island. But for years Mr Thin was arguing that people as well as deer should be able to raise their young there.

In 2009 Scottish ministers transferred ownership of the village of Kinloch, and land surrounding it, to the community to let it grow. The population is currently around 40 strong.

"I was on Rum last week and it is great what is happening now. The scientists are still doing research. But we have three young couples living in crofts that didn't exist before. There are pupils in the school. People are running B&Bs. Somebody has got a golf buggy to take people to the castle. There is somebody hiring bikes. Rum is transforming itself - with nature conservation underpinning a human revival."

He was also credited with being one of the first to see the potential of the Assynt Crofters' trailblazing buyout campaign in1992/93 which has led to over 500,000 acres of land being taken over by communities since.

He was working for Caithness and Sutherland Enterprise (CASE) when he persuaded bosses at Highlands and Islands Enterprise to back the crofters with £50,000. "At the time it was seen as radical and left wing. Community ownership smacked of communes. So it was questioned whether public money should be invested . But we could see this was about the self-respect of the crofting community, so was worth a try." His interests go beyond rural Scotland. He is currently on the board of Children's Hearings Scotland. "It was a personal thing. I applied because I think we have served our disadvantaged children relatively poorly in the UK as a whole."

He may be out of the firing line, but it is clear he will not be idle.