Squirrels say nuts to birth control

Published on Monday 4 June 2007 01:34

TRAPPING is cruel, shooting is tricky and poison is dangerous. If only there was a way to stop the grey squirrels advancing through Britain from breeding in the first place.

That was the thinking behind a government project aimed at protecting red squirrels from their foreign cousins by giving the grey invaders contraception.

But the 1 million project is set to end in failure and disappointment because the pesky creatures just won't take the pills.

Grey squirrels, originally imported to Britain from North America, are spreading through the country, out-breeding the native red squirrels and spreading a pox deadly to the smaller animals.

Campaigners fear that the greys will soon bring the disease across the Border into Scotland.

But trials of "immuno-contraceptive agents" on grey squirrels failed to devise a safe, reliable method of dispensing the drugs.

Scientists conducting the trials have been experimenting with special food hoppers accessible only by greys, to avoid the powerful drugs being consumed by other species.

However, devising a dispenser that reliably persuades the greys to take the contraceptive drug has so far eluded the researchers.

Progress has also been limited by a shortage of the contraceptive.

The three-year project is part of a study funded by the Department of Food and Rural Affairs (DEFRA) and the Forestry Commission. Separate trials have focused on giving contraceptives to wild boars and parakeets.

Although animal rights groups have backed the use of contraceptives, the squirrel trials, using captive greys, are taking place at a secret location due to fears of attack from animal-rights extremists.

The project is due to wind up next year, and the Forestry Commission said there are no plans to develop it in the wild.

"No decision has yet been taken on funding ongoing research beyond March 2008," said a spokesman for the commission, which is paying 40,000 towards the work. DEFRA

said: "It is too early to predict if or when the technique will be ready for use on wild populations." This is not the first squirrel contraception project to run into difficulties.

In 2002 the Forestry Commission and the Joint Nature Conservation Committee abandoned a study after researchers found it was impossible to replicate the successful laboratory trials under field conditions.

Earlier this year, authorities in Santa Monica, California, announced a contraception experiment, but they have not reported any significant success.

The Scottish Executive is understood to be funding a three-year squirrel-pox project, looking at how the virus is transmitted, to begin this month at a total cost of 300,000.

Scotland is the last UK haven for the red squirrel, as the species has been largely driven out of other parts of mainland Britain. More than 121,000 out of a total red squirrel population of 161,000 live north of the Border.

There are believed to be three million grey squirrels in the UK, but only 250,000 in Scotland.

There are still strong red squirrel populations in Dumfries and Galloway and the Borders but most are found north of the Highland line.