How the Scottish wildcat can be brought back from ‘extinction’ using cutting-edge genetics

Genetic profiling advances offer a new beacon of hope for bringing back one of Scotland’s most iconic animals, according to conservationists.

The Scottish wildcat, Felis silvestris, is the UK’s only surviving native cat species, but also its rarest and most threatened mammal.

Once found all across the country, it has almost completely vanished in recent times due to habitat loss and persecution and is now listed as critically endangered.

Today only a few – estimates range from 35 to 300 – remain, though none are believed to be pure-bred wildcats due to historical cross-breeding with domestic cats. Numbers are so low the species has been declared “functionally extinct” in the wild.

Major efforts are currently under way in a bid to reverse their predicament.

The Royal Zoological Society of Scotland (RZSS) is spearheading the Saving Wildcats partnership, a pioneering reintroduction project that aims to repopulate areas where the most wildcats are found.

The initiative involves breeding cats with a good pedigree in captivity and then releasing the best offspring in selected areas in the Highlands in the hope they will mate with each other and any remaining wild individuals.

The Scottish wildcat is the UK's only remaining native cat species, but also its most endangered mammal

The scheme, based at the RZSS’s Highland Wildlife Park at Kincraig, is already showing signs of success.

Adorable Scottish wildcat kittens make debut appearance at Highland Wildlife Park

The first releases took place last year, when 19 young cats were set free in the Cairngorms, and new wild-born kittens have been spotted recently.

Scientific advances

Today only a few wildcats remain in remote parts of Scotland, though none are believed to be pure-bred – numbers are so low that experts have concluded the species is “functionally extinct” in the wild

Now scientists say breakthroughs in genetics could benefit future conservation work.

Basic DNA profiling has already been used to create a “family tree”, or studbook, for all cats held in captivity – around 150 across the UK – and to select the animals most suitable for the breed-and-release project.

Pairing of the cats is carefully managed to avoid interbreeding with close relatives and minimise levels of hybridisation.

But the ability to sequence an entire genome, the full set of genetic instructions, could allow domestic cat ancestry to be selectively bred out of wildcats in the future.

A tagged wildcat – one 19 released in the Cairngorms last year as part of the pioneering Saving Wildcats breed-and-release project – has been spotted with her own brood of wild-born kittens in recent weeks

A new research paper, by RZSS and University of Bristol academics, suggests how this could be done.

“We had used traditional genetic analysis to make the pedigree and understand how all the cats are related and also to screen for hybridisation,” said Dr Helen Senn, head of conservation at RZSS and one of the study authors.

“Now we’ve got whole-genome data and that’s allowing us to look in detail along all the individual chromosomes and identify which bits come from wildcats and which bits come from domestic cats.”

Long-term vision

Knowing all this could help conservationists better select which animals to put together to ensure the widest genetic diversity while eradicating non-wildcat traits. At the moment the technique is theoretical, but it is likely to inform future conservation work, according to Dr Senn.

It would be part of a long-term vision for restoring the species over the next century – or two.

Dr Helen Senn is head of conservation at RZSS and one of the authors of the study on how genetic profiling could be used to improve efforts to save the Scottish wildcat from extinction

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Dr Senn said: “In reality, we don’t know how long it would take. It’s something that is likely to take multiple generations. It’s not a quick fix.

“But the situation for wildcats in the wild in Scotland is really perilous. If we’re lucky, we have just started to reverse the process of extinction. To reverse that fully could easily take another 100 years.”