A STUDY has found that Scotland’s wildcat population is “genomically extinct” due to extensive interbreeding with domestic cats.
The research published by the journal Current Biology on November 6 used DNA from modern and museum samples of both domestic cats and wildcats to track when hybridization of the species began.
While domestic cats have been present in Britain for more than 2000 years, the study found that hybridization of wildcats only began within the past 70 years.
Data from the mid-1950s found that just 5% of the genetic markers in wildcats resembled those of domestic cats in Scotland.
However, by 1997 the two species shared as much as 74% of their genetic markers in some samples.
The authors of the study say the marginal recovery of wildcats from an “exceedingly low” population contributed to the dilution of their genetics.
They propose that as the species sought to extend its range beyond the northwest Highlands and into central Scotland the low population meant that interbreeding became more likely.
Habitat degradation and the presence of wildcats in environments where humans live would also have resulted in meetings between domestic cats and wildcats becoming more likely.
“Our results indicate that the modern Scottish wildcat population is heavily admixed,” say the authors.
“In this regard it is technically ‘genomically extinct’ because we have found no unadmixed individuals.”
The DNA of contemporary Scottish wildcats is a “hybrid swarm” of both wild and domestic cats.
Ironically, this interbreeding may have helped surviving wildcat populations hang on as their DNA was found to be rich in genes which help pets fight diseases such as feline leukemia.
The authors said that reconstructing the ancestral wildcat genome is “theoretically feasible” although would likely necessitate the breeding of Scottish wildcats with wildcats from continental Europe.
The 160-strong population of captive wildcats in Scotland were found to share around 18% of their genetic markers with domestic cats.
During the summer 19 captive-bred individuals were released into Cairngorms National Park.
