Once-threatened British carnivores staging a comeback, research shows

Britain’s native carnivorous mammals, from otters to polecats, have staged a remarkable comeback in recent decades, a review has said.

With the exception of the wildcat, the fortunes of the mammals have markedly improved since the 1960s.

The animals have largely “recovered by themselves”, making a return once harmful human activities had been stopped or reduced.

Driven into decline as a result of hunting, trapping, control by gamekeepers, use of toxic chemicals and destruction of their habitat in the 19th and early 20th century, they were able to recover once the pressures were reduced.

Scientists from the University of Exeter, Vincent Wildlife Trust, the Centre for Ecology and Hydrology and Scottish Natural Heritage collected survey reports from the last 40 years to compare changes in populations and where species are found.

Pine marten have expanded from the Scottish Highlands (Robert Cruickshanks/PA)
Pine marten have expanded from the Scottish Highlands (Robert Cruickshanks/PA)

They also looked at human activities in recent decades that helped or hindered the species’ progress.

Otters, which faced problems ranging from hunting to harm caused by organochlorine pesticides, have almost completely recolonised Britain.

Badger populations have roughly doubled since the 1980s, though they face increasingly widespread, intensive culling, while fox numbers are up since the 1960s, though an apparent decline in the last decade may be due to dwindling rabbit numbers.

And two of the rarer carnivores, pine martens and polecats, have staged “remarkable recoveries”, the paper published in the journal Mammal Review found.

Polecats have expanded across southern Britain from Wales, and pine martens have spread from the Scottish Highlands.

Wildcats are the exception, now restricted to small numbers in isolated parts of the Scottish Highlands and suffering declines largely as a result of inter-breeding with domestic cats.

And the status of stoats and weasels remains largely unknown, the review found.

Lead author Katie Sainsbury, from the University of Exeter said: “Unlike most carnivores across the world, which are declining rapidly, British carnivores declined to their low points decades ago and are now bouncing back.

“Carnivores have recovered in a way that would have seemed incredibly unlikely in the 1970s, when extinction of some species looked like a real possibility.”

Professor Robbie McDonald, head of Exeter’s Wildlife Science group, said: “Most of these animals declined in the 19th Century, but they are coming back as a result of legal protection, conservation, removal of pollutants and restoration of habitats.

“The recovery of predatory mammals in Britain shows what happens when you reduce the threats that animals face.

“For the most part these species have recovered by themselves.”

He added that reintroductions of groups of animals such as pine martens was also helping the species reestablish themselves.

Work is now needed to find ways to prevent conflict between growing numbers of the carnivorous mammals and people such as gamekeepers, anglers and farmers they may cause problems for, the experts said.