Very few people have ever had the thrill of observing the Scottish wildcat in its natural habitat, but the cats themselves are experts in surveillance.

On a blazing hot day at Highland Wildlife Park, the trees sheltering the wildcat enclosure provide a haven of cool, zesty air. This is the cheat's way to see wildcats but it provides an unbeatable front-row view, and this morning's visitors are in for an appearance by today's celebrity guests, the wildcat kittens. All that's visible of them is a squirming ball of fawn and grey fur that suddenly springs apart to become two tiny cats, who each stand unsteadily for a moment looking dazed. Then one bats the other provocatively with his forepaw and they're rolling around again, miniature teeth bared with mock ferocity, bashing into their mother, Susie, who is basking in the sunlight.

The watching visitors are entranced and consequently oblivious to the fact they themselves are under scrutiny. Above their heads, on an enclosed walkway between the trees, two unblinking yellow-green eyes are trained on the gaggle of humans below. They are set in a broad, elliptical face with small, pointed ears. It is not a friendly face. This is Hamish, who sired the kittens. Sitting stock-still, as stately as a lion, he is camouflaged against the woody backdrop; even his thick, stubby, black-ringed tail, which hangs down between the mesh squares like a giant caterpillar, melds into the background.

Nobody seems to notice him there. Or almost nobody.

"Pussy cat!" Suddenly, a tiny, pudgy finger belonging to a toddler in a blue T-shirt is pointing upwards. Everyone turns and looks up at Hamish. Oh, the indignity. He trains his disdainful eyes on the little boy, then stands up and springs down the ramp into the enclosure. "Look, there!" says the boy, stumbling towards Hamish and grabbing the mesh, just below the sign that says: "These animals bite." Hamish looks like he's thinking about it, but the boy's mother soon whisks him out of harm's way.

The animals are one of the big attractions at the park in Kincraig,which is run by the Royal Zoological Society of Scotland (RZSS). Feeding time always attracts a crowd.

Yet are Hamish and Susie even Scottish wildcats, or are we cooing over creatures that are actually hybrids – part wildcat, part moggy? The sobering truth is that nobody actually knows – or at least, not yet.

A genetic test is currently under development which, if successful, will show definitively whether individual cats are pure-bred wildcats or hybrids. The test, which could be ready by Christmas, would pave the way for further, much-needed wildcat conservation work. It would allow for the testing of cats both in captivity and in the wild and for measures to be taken to protect those pure-bred wildcats that remained from being hybridised into extinction.

However, some conservationists, such as Steve Piper of the Scottish Wildcat Association and geneticist Dr Paul O'Donoghue, are deeply concerned that, although the test should soon be ready, there are no firm plans officially in place to set up a targeted conservation programme for those few remaining true Scottish wildcats. It's a question that must be resolved soon, they stress, if the subspecies is to be saved from going quietly extinct in as little as five years.

The current official estimate of 400 Scottish wildcats remaining in the wild is an informed guess; the worst-case scenario – that there is none – is a genuine possibility.

In captivity, the situation is just as worrying. Neville Buck, of Howlett's Wildlife Parks in England, holds the studbook for the Scottish wildcat, a record of all captive wildcats including their family tree, birth date and purity. According to Buck, only one animal out of a captive population of 75 is currently graded as a pure-bred. A further dozen show some hybrid characteristics while the majority are clear hybrids. Good-looking specimens as they are, the "wildcats" at Highland Wildlife Park, probably aren't that.

Having reviewed photos of cats in the wild from motion-sensor-activated camera traps, most experts believe a small number of true wildcats probably do remain, but time is running out for them and with no buffer of a captive pure-bred population, the situation is extremely urgent, says Buck. As Douglas Richardson, animal collections manager at the Highland Wildlife Park, puts it, "We get our knickers in a twist because the Indians aren't doing all they can to protect their tigers, or the Kenyans their black rhinos, but it's OK for us to let this one slip through the net? I don't think so.

"Here we have this iconic emblem of the Highlands and if we don't get our finger out, it will become extinct, guaranteed."

Wildcats are the only remaining large mammal predator and the only surviving cat native to Britain. Persecution and deforestation contributed to a drop in numbers during the 18th and 19th centuries, but although suitable habitat has increased again, their numbers have continued to dwindle, due partly to disease and road accidents, but mainly to interbreeding with domestic cats (one study in 1995 estimated the population of feral cats in the Highlands at 100,000). A population of hybrid cats now exists alongside wildcats.

"If you let dogs run feral, people would be up in arms for a very good reason. Cats? They think it's all right," says Richardson. "We don't want to stop anyone having cats, but we want to shut off the taps of more animals going to live a feral existence and cross-breeding with wildcats."

Educating people in Highland areas about the importance of neutering and inoculating domestic cats was one of the main aims of the recently concluded Cairngorms Wildcat Project, run by the Cairngorms National Park Authority (CNPA), Forestry Commission Scotland, RZSS, Scottish Gamekeepers Association and Scottish Natural Heritage (SNH).

Yet wildcat conservationists agree that education alone is not enough to save a species that is more threatened than the tiger. They insist that those pure-bred wildcats which remain in Scotland need to be definitively identified and protected, which is why many see the genetic test as so crucial.

Currently, the best way of telling a pure-bred Scottish wildcat from a hybrid is somewhat problematic. The length of its gut, fusion of bones on its head and shape of its jaw are tell-tale signs, which can be examined if the specimen is dead, but are not much help if it's alive.

With living cats, identification involves examining their pelage, or coat characteristics, in detail. Trying to do this from camera trap images, however, is difficult, as they are often fleeting and indistinct, and may be taken from the wrong angle. This dubiety explains why nobody knows for sure how many real wildcats there are left.

Cast-iron proof could come from a diagnostic genetic test. The work to create one has been developed by Dr Paul O'Donoghue, a senior lecturer at the University of Chester, in partnership with Dr Ross McEwing at the RZSS WildGenes Lab in Edinburgh. Funded by the Aspinall Foundation, the University of Chester and the People's Trust For Endangered Species, the work involves using state-of-the-art technology to scan the entire Scottish wildcat genome, examining 63,000 genetic markers.

The team have set out to find the best available examples of pure-bred Scottish wildcats to provide their gold-standard reference sample and this means looking at stuffed cats in museums. Andrew Kitchener of the National Museums of Scotland, the country's leading authority on identifying Scottish wildcats, has highlighted the best "pelage perfect" specimens. The oldest one is 132 years old from the British Museum.

DNA will be extracted from these museum samples and the whole genome scanned. The same will be done for domestic cats and the two lots then compared to identify the pure wildcat reference markers. A subset of definitive "wildcat markers" will then be identified, which will form the basis of the diagnostic test.

A cat found to have 100% of the wildcat markers would be deemed a pure-bred wildcat, but the test would also show if a cat was 25%, 70% or 90% wildcat.

The domestic cat first came to the British isles 2000 years ago so it's possible even the museum samples might not be 100% pure-bred, but as O'Donoghue says, they are "the best we've got".

So far the work is "incredibly encouraging", he says. Samples from the British Museum cats are to be analysed in the autumn and he hopes the wildcat markers will have been identified by Christmas. "Initial results strongly suggest a diagnostic wildcat test will be available," he says.

Conservationists such as Steve Piper would then like the test to be used on animals trapped in the wild to establish once and for all how many wildcats remain in Scotland and where they are.

Piper then favours creating a so-called "mainland island" on a peninsula such as Ardnamurchan. Provided enough pure-bred wildcats were found to make a breeding population viable, this would involve the setting up of a "buffer zone" of live traps at the mouth of the peninsula to prevent cats coming in. Pure-bred wildcats could then live in the area without the risk of interbreeding with ferals or hybrids. Numbers would then hopefully rise.

Unlike with the controversial scheme to save the red squirrel, which involves the killing of trapped grey squirrels in the buffer zone, both hybrids and feral cats would be neutered and released again, provided they were healthy. Not only would such an approach be more humane, but it would also prevent a vacuum arising in the ecosystem that could draw in further cats. The plan was two years in the development, he says, involving "everyone SNH has ever used as a wildcat expert" plus others with veterinary and forestry expertise, geneticists and experts on feral cats.

Piper is disappointed, however, about the reception his plan has had from SNH. He put in a licence application for wildcat trapping nearly a year ago because he wants to start building a collection of blood samples that can be tested as soon as the genetic test is ready, but the licence has not yet been granted. He says SNH have asked him to do more camera-trap surveying first but believes the wildcat could be beyond help in two years.

"The Scottish Government and SNH collectively are extremely cautious with regards to EU regulations about the disturbance of wildcats," he explains, sounding exasperated. "The sticking point is that to be able to do any of this work, they have to be disturbed. We need to trap the cats to get blood samples. It's a really unfortunate situation."

O'Donoghue has similar concerns. "If we look hard enough," he says, "we will be able to find pure wildcats. I'm still hopeful of that. But the point to stress is there won't be any wildcats much longer. We've got to act decisively and immediately."

He believes there could be fewer than 100 wildcats left. "The real issue is, how do you reduce hybridisation? Nobody in the whole of Scotland is doing anything at all to stop this."

O'Donoghue is impatient for more than surveys. "The wildcat is being camera-trapped into extinction – it's as simple as that," he says.

A spokesman for SNH, however, insists the agency is committed to conservation of the Scottish wildcat but says "the current low numbers mean that work must be carried out in a co-ordinated fashion".

"Having a more focused and strategic approach to conservation work means making sure everyone works together and making the best use of our resources will help ensure this happens. For instance, we recognise the efforts that some land managers and estates have made toward wildcat conservation and we are committed to working with them and across the sector as a whole."

He adds that the genetic test would be "a useful first step in providing a better understanding of the current wildcat population" and says, "We do licence wildcat work. In order to do so we need to ensure the correct balance is struck between potential harm to the species and the scientific benefits arising from the research. The threshold for granting licences remains high and we believe this is vital to help safeguard the future of the wildcat."

O'Donoghue is also critical of the Cairngorms Wildcat Project (CWP). "No meaningful conservation benefit was gained from the CWP to deal with the issue of hybridisation," he says. "Raising awareness is important, but it will not save the wildcat. Direct intervention in the wild population yesterday is what will save the wildcat."

Others, however, believe the CWP carried out essential groundwork for further efforts to prevent hybridisation based on the genetic test. The camera trap data has identified areas where there are cats that look like true wildcats, says Buck, which means that when the genetic test is ready, live traps can be set up in the right places.

"Everything that everyone has done up until now, it's not been wasted because it's all been useful information," he says. "Without it we wouldn't be able to move forward."

SNH points to the value of the CWP in expanding feral cat trap-neuter-release work, improving the ability of gamekeepers to identify likely wildcats, and in developing camera trapping methods as a useful tool for monitoring wild-living cats.

Douglas Richardson, who was the RZSS's member on the steering committee for the project, confirms the project had "an enormous amount of support" from the gamekeeper community. He also highlights the value of the project in raising public awareness of the wildcat's plight and pushing it up the political agenda. "It should not be forgotten that we have an independence referendum coming up," he notes. "To a lot of people the Scottish wildcat is seen as an icon of Scotland." As for encouraging people living in the Highlands to get their cats neutered, he hopes the message has got through.

Yet all agree decisive action is now needed to save the cat from extinction.

That assumes Scottish wildcats still exist in the wild. What, though, if no pure-bred cats are found? If there is none or there are too few to be sustainable in the wild in a given area, then the best hybrids will have to be retained for breeding, says Piper. In the captive population, it all gets a bit Jurassic Park as attempts would likely be made to "backbreed for purity" by selecting those hybrids bearing the highest percentage of wildcat DNA and breeding them together. Similar approaches have been taken with other species, such as Pere David's deer from China, which was hunted to extinction except for a small population that had been smuggled to Europe and collected together at Woburn Abbey in Bedfordshire. There was some hybridisation of this herd with a red deer stag, but the red deer characteristics were subsequently selected out. Similarly, the Przewalski's horse – which can be seen at the Highland Wildlife Park – went extinct in Mongolia but its numbers have been built up again from a captive population of a dozen animals, one of which was a domestic mare.

Ultimately, everyone hopes that it is not too late to find a complete breeding population of true wildcats, provided action is taken soon.

Otherwise museum specimens will be all that's left of the true and original Highland Tiger. n

Visit www.scottishwildcats.co.uk and www.highlandtiger.com.