Pioneering polecats making a return to Suffolk
PUBLISHED: 08:00 10 March 2018
Suffolk Mammal Conference told of county comeback for masked mustelid
One of the UK’s most heavily persecuted mammals, which was exterminated in Suffolk by gamekeepers more than 100 years ago, is back in the county after an “eastward march” across the country.
Polecats, bandit-masked mustelids whose close relatives include ferrets, stoats and weasels, have returned to Suffolk after population recoveries to the west. They have crossed the Essex border into several parts of Suffolk, the recent Suffolk Mammal Conference was told.
Lizzie Croose, the mustelid officer for the mammal research and conservation charity the Vincent Wildlife Trust, told the conference at Wherstead Park, Ipswich, that polecats had been driven to extinction in Suffolk by about 1900. However, re-colonisation of the west of the county began in the early 2000s.
In a European context, the UK was “bucking a trend” of polecat decline, with Britain and Switzerland being the only countries in which population increases had been recorded, she said.
The UK’s increase was set against a “sad history” of persecution. Polecats were formerly widespread but by 1800 they were only to be found in Wales, the Borders and northern Scotland. By 1915 their range had contracted further, to mid-Wales, the Borders, Herefordshire and Shropshire.
A UK recovery began in the 1940s and 1950s following reduced levels of gamekeeping, a gin trap ban and a recovery in the UK rabbit population. Parts of the polecat’s former range were re-colonised and re-introductions took place in some areas.
“Now they are continuing to march eastwards into Suffolk and East Anglia is among the areas with the most extensive re-colonisation,” said Ms Croose.
Despite their apparent success story, polecats still faced a number of threats, however.
One major problem was the incidence of “secondary rodenticide ingestion” in which the polecats preyed on rodents such as rats that had been poisoned. In the 1990s tests showed that 31% of polecats analysed had ingested rodenticide in such a way but in 2014-2015 the level had risen to 79% and this was a “worrying trend.”
Accidental or deliberate trapping was another threat to polecats. So was hybridisation with domesticated or feral ferrets, which was blurring the true status of the species and making formal recording of it more difficult.