The strangest felines

THE weather over the past week has been fit for neither man nor beast. How odd then to find myself in the company of a man who has spent his adult life searching for some particular beasts - black panther-like creatures which he believes are roaming Scotland. It is Thursday lunchtime and Mark Fraser is, as usual, on the prowl.

"We are now entering what I call Big Cat Country," he says as we drive through fields outside the Ayrshire village of Kilmaurs. "In Stewarton, where we are heading now, there have been a lot of sightings. The cats don't stick to any particular terrain. They will actually come into towns. In Kilmarnock, one was seen by a postman in the middle of a housing estate. But the majority of sightings you get here are melanistic cats running across the road."

Melanistic, meaning very dark or black, is a word often used by big cat investigators. There are only five such people in Scotland, which doesn't sound many until you remember the big cat population is estimated at just 40, eight to every human looking for them. Any animals which would rather not be found would do well to make for the Edinburgh area. Fraser's research group Big Cats In Britain, run from his home in Kilmaurs, has representatives in Ayrshire, Aberdeenshire, Argyll, Fife and Lanarkshire, but not Lothian, "which is a shame," says Fraser, "because there's been a helluva lot of sightings in the Pentlands".

Slowing as he drives into Stewarton, "The Bonnet Toun", better known for hats than cats, Fraser takes a long draw on a fag. At 46, he's a heavy-set heavy smoker with tattooed arms who drives a van and works in the security industry. He's also from an area of Yorkshire which he refers to by its old-fashioned name, the East Riding.

In other words, Fraser should be the very personification of no-nonsense. Yet his interest in strange phenomena dates back to his childhood in Hull, and he describes himself, unblushingly, as a cryptozoologist – one who studies animals thought to be legendary or which should not be found in a particular environment. "Chimpanzees," he offers by way of illustration, "have established colonies in quite a few places in Britain."

Not in Scotland, though, surely? "No, more in Sussex, Surrey way. Mind you, there was a dead monkey found in Inverness-shire, and we've had sightings of baboons in Ayr."

He pulls up at the side of Cunningham-Watt Park and we walk into the woods, along the course of a burn. There's a rusty Irn-Bru can on the ground and buzzards in the air. The Ayrshire countryside in autumn and winter has an indefinable eeriness, something to do with black branches against white sky, with hawthorn hedges hemming in narrow roads. This is Tam O'Shanter country, remember, where the devil appeared as a "towzie tyke".

It's easy to believe that nature has taken a turn for the curious round here. In 1816, the remains of eight mammoths were discovered in a quarry near Kilmaurs, and somehow it wouldn't be entirely surprising if some kind of relic had survived into an age in which it has no business. That's one theory about these big cats – they are an indigenous species that has been around since the Ice Age.

Fraser has spotted something. He hunkers down to examine a large paw print in the mud, then straightens back up with a shake of his head. "Dog," he sighs.

Every year, usually during the summer "silly season", the newspapers report "sensational" pictures have been taken of what appears to be a leopard or jaguar. Cameras in mobile phones and the advent of YouTube have meant that this is more common than ever. In July, the big story was footage of a black cat walking along the railway line in Helensburgh. This came only a week after reports that a horse in Ayrshire had been savaged by a puma.

It's often said that if there are big cats in Britain then they are the descendants of beasts released by their owners following the introduction of the Dangerous Wild Animals Act of 1976. The chief proponent of the opposite view, that the cats are an indigenous species, is Di Francis, a Londoner now living in Banffshire.

Francis pioneered big cat investigations in Britain. It began in the late 1970s when she was living in Devon and working as a journalist covering British wildlife. She was running out of subjects. "I'd actually got down to writing about the sex life of slugs," she says when I phone her, and she'd suggested to her editor that she look into the sightings of a so-called "black puma" near Tedburn St Mary. This was the beginning of a "life-ruining" fascination. One winter she spent six weeks camped on Dartmoor in the snow, the better to see any prints. She caught no cats, but did develop hypothermia. Still, her persistence paid off when, on St David's Day, 1982, she took the first daytime photograph of a British big cat – a black animal larger than the Doberman bounding along beside it.

Francis claims to have made a further six sightings since 1982, some in Scotland. She is desperate for hard evidence the black cats exist and thinks the best chance is for one to be discovered as roadkill. If any readers should find one, she asks that you conceal it on the verge before contacting Big Cats In Britain. "Better of course to shove it in the boot and take it home," she says, "but we understand a lot of people may not be as enthusiastic as we are."

These days, aged 66, Francis does most of her research at her desk, and the most exotic creatures she sees are woodpeckers on the bird table. She leaves the camping out and wandering around the woods at night to younger investigators. Yet she has lost none of her passion for the big cats, which she praises for their beauty, power and intelligence. "I should be so disappointed," she says, "if I died before we got one."

Back in Kilmaurs, Fraser drapes his camouflage jacket over a chair and shows me the office upstairs in his semi-detached from where he runs Big Cats In Britain. It is a small room, a den really, and unmistakably the workspace of a man on a mission. By the window, with its views over the fields, there are night-vision binoculars. The bookshelves are full of feline literature, including Fraser's own Big Cats In Britain Yearbook, the cover of which features the proud boast, "Voted 4th in the world's top ten cryptozoological titles of 2008". Elsewhere on the shelves are animal skulls with pronounced canines and a stuffed melanistic wildcat, a gift from Francis. "My wife can't stand that in the house," says Fraser. "She's allergic to cats."

A trip across the hall to the toilet confirms that Fraser's favoured brand of deodorant is Lynx. Less fragrant are the small bottles of a foul concoction, made from the glands of bobcats, which he keeps in his office. The idea is that this liquid will lure a big cat into a cage set up for this purpose, "but we haven't caught nowt yet, apart from dogs and pussycats".

He would prefer not to use the bobcat potion. "The best thing is actually the urine and faeces of another big cat," he says. "I drove home from England with a load of leopard faeces in the back once. You've never smelled anything like it. We used to get it from zoos, but since the foot-and-mouth scare, it's virtually impossible to get hold of."

From this nerve centre, Fraser co-ordinates all British sightings of mysterious cats. Each week, he hears of four or five via phone and the BCIB website. This year, there have been around 200 in Scotland alone. When a cluster of reports come from one place, he will travel there, examine evidence and interview witnesses. I sense, though, a certain weariness as he scrolls through photo s he has been emailed. "Domestic cat," he intones. "Fox. Cat. That's a domestic cat, too. But it does have a funny face."

Fraser saw his first big black cat one evening in 2003. He can be specific – it was 19 November. Scotland were getting humped 6-0 by the Netherlands, and he was watching the game when someone called to say that there was a cat in the area and he had better get a move on. When he spotted the animal, which he estimates at 3ft high, "It was a relief because that had been 15 years and I'd never seen one. You do begin to think that you might be wasting your time. That's why I chased the bugger. Fifteen years – I'm not letting that get away."

But get away it did. "It was so good to see it," Fraser smiles at the memory. "I rang the wife. I said, 'I've seen one at last,' and she said, 'Yeah, I'm watching Emmerdale.'"

His wife Hannah thinks he is obsessed, and he thinks she is probably right. "It can take over at times," he nods. "You try to back away from it, but your phone goes, and you think, that could be the one."

He smiles wearily. "Never bloody is, though."