SCIENTISTS want to put grey squirrels on the pill to stop them taking over our countryside. The rodents, introduced to Britain from America in 1876, have bred so successfully that they have had a devastating effect on our native red squirrel.

Now government experts want to administer a drug to halt the population explosion and an immuno-contraceptive is now being refined.

The grey squirrel is one of the most successful breeding species of the age and is now prolific across woods, forests, urban parks and gardens.

Its rise has led to a corresponding decline in the red squirrel, inspiration for Beatrix Potter's Squirrel Nutkin, and Tufty, figurehead of the children's road safety campaign.

The disease-carrying, heavier and more ravenous grey squirrel has slowly pushed its delicate cousin to ever more remote parts of the countryside.

The remaining 161,000 red squirrels are now confined to parts of northern England, Scotland and Wales, along with a small isolated population on Brownsea Island.

Grey squirrels have also been blamed for the decline of many woodland birds such as the hawfinch.

Later this month the government and the Forestry Commission will be publishing plans to curb their numbers.

Biodiversity minister and South Dorset MP Jim Knight has been heavily involved in this process.

"Grey squirrels do cause problems but they are very difficult to control," he said.

"I think eradication is probably impossible because the population is too widespread.

"We are working hard on a form of immuno-contraception for grey squirrels.

"We have got a little bit more work to do to make sure it's sufficiently species-specific but we are working hard on the science to see if we can find a way."

Squirrel numbers were once controlled more brutally.

In 1953, the Daily Echo reported how a dawn cull in Bournemouth Gardens saw 47 squirrels killed as part of a national drive to reduce their numbers.

Mr Knight's comments came after a guest on Radio 4's Today programme argued for a squirrel cull, claiming "bunny-hugging" conservation groups were too timid to tackle the issue.

First published: November 8