LONDON (Reuters) - Current efforts to control Britain's increasing deer numbers are not enough to stop populations spreading out of control, research by the University of East Anglia showed on Thursday.
There are now more deer in Britain than at any time since the Ice Age, the scientists said.
Without natural predators, populations are continuing to rise, causing a serious threat to biodiversity. High numbers of deer can threaten woodland birds, carry infections such as Lyme disease, damage crops and cause road traffic accidents.
The research team studied the numbers, sex ratio and fertility of roe and muntjac deer across 234 km sq of forested land and heathland in Breckland, East Anglia, to measure the effectiveness of deer management.
The team found that while deer management appeared to control numbers at a stable level, it was only because thousands of deer are pushed out to the surrounding countryside each year, helping to drive the further spread of the animals.
In the Breckland area studied, 53 percent of muntjac from the estimated population need to be culled and 60 percent of roe deer just to offset reproduction, the scientists said.
These figures exceed previous cull recommendations of 30 percent of muntjac and 20 percent of roe.
Even higher numbers could need to be culled if populations are to be reduced, the scientists added.
"Native deer are an important part of our wildlife that add beauty and excitement to the countryside, but left unchecked they threaten our woodland biodiversity," said Kristin Waber, who conducted the study while a postgraduate student at the University of East Anglia.
"Trying to control deer without a robust understanding of their true numbers can be like sleepwalking into disaster. To effectively reduce and stabilize the population establishing numbers is vital," she added.
Culling large numbers of animals can be an emotive issue in Britain, which sees itself as a nation of animal lovers.
The British government was considering a badger cull last year to stop the spread of tuberculosis in cattle but delayed the plan due to public opposition.
Critics said the cull would be ineffective and public opposition was widespread, more than 150,000 people signing an online protest petition initiated by former Queen guitarist Brian May.
Editing by Jon Hemming