Super-rat and mouse study appeals for tail tip samples

An appeal for pest control technicians, farmers and gamekeepers to collect tail samples from freshly killed rats and mice has been issued by the Campaign for Responsible Rodenticide Use. They will be analysed for rodenticide resistance genes and the results added to an online national map here.

Before sending tail tips, participants need to read guidelines from University of Reading’s Vertebrate Pests Unit, where the genetic finger printing is being done. The deadline is 29 May and every sender will be notified of their own results. The guidelines are available here and a factsheet with the same information can be downloaded from here.

In the past two years, new hotspots of rats with resistance genes have been found in Northumberland and County Durham, Tyneside and North Yorkshire, Greater Manchester and along the River Severn valley from north-west Shropshire to Somerset, Devon and East Anglia.

Over a number of years, resistance genes have become widespread across central southern England. Leader of CRRU’s Monitoring Work Group Richard Moseley says a serious concern is the almost complete lack of data from central England and most parts of Scotland, Wales and Northern Ireland.

We can only manage the spread of resistance when we know where it is,” he says. “Currently we have the worst of both worlds.

Farmers, pest control technicians and gamekeepers could be using products that are ineffective in places where rodents are resistant. And where resistance genes are still absent, others may be using resistance-breaking products unnecessarily. Only more samples can solve this.