Experts are urging drastic measurers to cull the soaring deer population in Britain.
New research suggests that only by killing 50-60% of the animals can their numbers be kept under some control.
The number of deer in the UK is estimated at 1.5 million - meaning a cull could result in more than 750,000 animals being shot.
They are having a damaging effect on woodland and farmers' crops. They are also causing an increasing number of accidents.
Each year about 450 people are injured or killed on the roads and more than 14,000 vehicles are severely damaged as a result of collisions with deer.
Research Fellow Kristin Waeber, from the University of East Anglia, said: "I think deer belong in the landscape, but if we let the deer numbers increase even more, then we have to make a decision that we lose our woodlands, our bluebells, our oxlips, because the deer will just eat them.
"So are we okay in compromising that in just having a lot of deer about? I think it is important to keep a balance."
She says the deer are disturbing the ecology so much that native birds are being wiped out. The fact that nightingales are now so rare is largely blamed on deer.
Thetford Forest has about 14,000 deer in 52,000 acres. They shoot about 2,000 a year and the bodies are sent to local game dealers.
Trevor Banham, chief wildlife ranger at Thetford Forest, said: "We have a part to play in this. We have to try to manage this population and if we don't, we have this process that is going on now where they are starting to go out of control.
"It is needed, the cull is needed all the time."
The RSPCA says it is opposed in principle to the killing or taking of all wild animals unless there is strong evidence to support it.
It is urging controlled methods, where a cull must be taken on a case-by-case basis. They do not want it to be rolled out in a uniform way across the country.
Although they were kept on private land belonging to the nobility, native wild deer were virtually unknown in England for 1,000 years until their re-introduction by the Victorians.
Today, there are more deer in the UK than at any time since the Ice Age.