Difficult discussions about culling wildlife have once again sparked a heated debate - but this time it is evidence gathered here in Norfolk and Suffolk that has led to the latest calls for action.

New research from the University of East Anglia (UEA) has called for an increase of over 20pc in the culling of muntjac deer and over 30pc of roe deer.

The UEA research, published yesterday in the Journal of Wildlife Management, says deer are causing 'a serious threat to biodiversity', as well as crashes on our roads and damage to crops.

The research was carried out across 234kmsq of forested land and heathland in the Breckland area along the Norfolk and Suffolk border, including Thetford Forest.

The results, showing for the first time that present management efforts are not enough to stop deer populations spreading out of control, have sparked a national debate about culling deer.

Deer may be culled in season by authorised people using appropriate equipment, during the day only. Muntjac are the only species in the UK not to have a close season and may be culled all year round.

The researchers drove more than 1,140 miles at night and used thermal imaging and night vision equipment to investigate the numbers, sex ratio and fertility of roe and muntjac deer.

Lead researcher Dr Paul Dolman, from the UEA's school of environmental sciences, said: 'Deer management is often based on guesswork. This is the first time that a population has been quantified and studied in terms of how the deer are breeding - to measure the effectiveness of deer management.'

The report states there are more deer in the UK than at any time since the last ice age, and with an absence of natural predators, populations are continuing to expand.

It found that while deer management appeared to control numbers at a stable level, this was only because thousands of deer are 'pushed out' to the surrounding countryside each year, helping drive the further spread of deer.

The researchers identified a necessary cull of 1,864 muntjac from an estimated population of 3,516 (53pc) in the Breckland area and 1,327 roe deer out of 2,211 (60pc) just to offset productivity - with greater numbers needing to be culled if populations are to be reduced.

These figures greatly exceed previous cull recommendations for muntjac (30pc) and roe (20pc).

Dr Kristin Wäber, who conducted the study while a PhD student at the UEA, said: '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.

'In Thetford Forest, despite an active programme of professional management culling thousand of deer, the numbers culled did not offset productivity.

'Increasing deer populations are a serious threat to biodiversity – particularly impacting on woodland birds such as migrant warblers and the nightingale.

'They also carry diseases such as Lymes and if numbers are not properly managed, they can cause damage to crops as well as road traffic accidents.'

The Deer Aware campaign, which is sponsored by the Highways Agency and the Woodland Trust, estimates that 74,000 crashes on the UK's roads involve deer every year.

With this in mind, special provision is being made along the final stretch of the A11 which is becoming dual-carriageway, including through Thetford Forest.

A Highways Agency spokesman said: 'When the dual-carriageway is finished on that part of the A11, there will be deer vicinity zones through woodland areas.

'There will be some wider-than-average verges, they will be 10m verges, so that drivers will see deer from further away.

'We consulted with all the local partners and recognised the high deer population in the area.'

But it seems culling remains the only viable option for reducing that deer population.

A statement released by the RSPCA said it was 'opposed in principle' to the killing of all wild animals unless there was 'strong science' to support it and no evidence of appropriate alternatives.

But the UEA research did not have the RSPCA totally convinced, with the statement continuing: 'Any decision to carry out a cull must be taken on a case-by-case basis, based on the specific issues which impact a specific area.

'We don't believe this should be rolled out in a uniform way across the whole country. It is certainly not a case of one size fits all.'

But a spokesman for the Country Land and Business Association (CLA) welcomed the research, saying: 'The excellent research by the University of East Anglia in the east of England has confirmed our belief that the current cull numbers are not enough even to retain deer numbers at existing levels let alone reduce the population to a level where it stops impacting adversely on the natural environment.

'Woodlands are also under attack from a large number of insect pests and tree diseases such as Chalara, many of which are impossible to control.

'Therefore, it is even more important that we start effective management of threats such as deer and grey squirrels where we could have a beneficial effect.'

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