Extinction beckons for Britain's well-loved native mammals

Efforts to preserve the country's wildlife have had mixed success, scientists warn. Now the possible introduction of GM crops could make things worse. Terry Kirby reports

In his classic tale of animal lifeWind in the Willows, Kenneth Grahame evoked a timeless countryside rich with Britain's much-loved native mammals such as the water vole and the badger. The reality is that, for many years, a large number of these animals have been under threat from both man and imported predators, such as the mink.

Now a new audit of Britain's mammals warns that the intensive efforts of conservationists and the Government to protect and preserve these creatures and their habitats may only be having mixed success.

For some creatures, such as the red squirrel, extinction beckons in parts of Britain where they were once numerous, whereas others - such as the water vole (also known as the water rat, hence Grahame's character 'Ratty') - are depleted but managing to survive. The badger (the wise counsellor of Grahame's book) may be relatively numerous, but it is now under threat from culling and climate change.

According to the audit, The State of Britain's Mammals 2004, compiled by the Wildlife Conservation Unit at Oxford University, the possible introduction of genetically modified crops threatens bio-diversity by reducing the numbers of insects around such food crops with "potentially serious consequences" for the hedgehogs, wood mice and bats that rely upon them for their basic food. Organic farms, it says, provide better environments.

The report, prepared for the Mammals Trust UK by Professor David Macdonald, the head of the unit and one of Britain's leading mammal experts, and Dr Fran Tattersall, his colleague, says: "Big forces operate through small changes to bequeath large, often unexpected and unwelcome consequences ... climate change and massive bio-diversity loss are upon us and both present change that must be managed." It warns that tighter legislation may be needed to protect some animals and says that conservation must be landscape as well as site-based and pay attention to wider issues in society.

The authors call for a national mammal monitoring service to assess which animals and their habitats might be under threat, citing studies of polecats and cetaceans as proof of how their numbers can be assessed.

Tackling big problems such as climate change, says the report, requires an understanding of small details. It cites how attempts to control the spread of Bovine tuberculosis by culling badgers backfired, causing a 27 per cent increase in the disease in cattle in culling areas, possibly because the cull had affected the intricacies of badger behaviour in a way not yet fully comprehended.

Studies of badger setts have shown that dry springs in 2002 and 2003 resulted in the lowest numbers of surviving badger cubs ever recorded. This was believed to be partially because they were unable to find sufficient numbers of earthworms, their staple food, and the lack of water led to dehydration in cubs, which suffer from a diarrhoea-inducing gut parasite.

A different kind of problem is affecting the Scottish wildcat, one of Britain's rarest mammals and confined to the Scottish Highlands. The report says that, in some cases, it is no longer possible for scientists to state accurately that a cat is a wildcat because interbreeding with feral domestic cats has diluted the gene pool. "British law is not adequate to ensure the conservation of Scottish wildcats," says the report. Only 400 true wildcats may survive but many more "wild-living" cats with wildcat characteristics exist and the law should be amended to allow their protection, the report says.

But the report's direst warnings are reserved for the red squirrel, which has been in decline since the introduction of the American grey squirrel in the 1920s which competes for its habitat. The report says: "The red squirrel's precarious situation and its eventual extinction in mainland England, Wales and southern Scotland seems inevitable." It is already largely extinct in southern and central England. Large-scale control of the grey squirrel population and the development of a vaccine against squirrel parapoxvirus - which has particularly hit the Merseyside population, one of the largest left in England - are required urgently, says the report. Greys are also spreading through the Cumbria and Kielder Forest areas and have been sighted on the Isle of Wight, previously a grey-free area.

Some animals, says the report, are beginning to thrive again, thanks to the careful management schemes. The otter, which was once in danger of dying out is breeding again in many parts of north-west Scotland and England due to their successful reintroduction. A by-product of this is that the American mink population has declined - reducing by about 65 per cent between 1989 and 1998 - while that of the otter has increased, because both compete for aquatic prey, such as fish. As the density of otters increases, minks shift towards terrestrial prey, such as rabbits and voles, but when these are scarce, the mink will often be killed by otters or abandon the area. Mink are also predators of water voles, so their decline helps this creature, now scarce in many parts of Britain due largely to farming techniques and competition from livestock. Conservationists have created 14 reed bed and marsh sites which offer better protection against the mink for the water vole than open water.

There is similar hope for the Pipestrelle bat, once numerous but now depleted largely because of erosion of their natural habitat due to intensive agriculture. The report notes how the law now protects bats. A two-year survey from 2001 to 2003 showed that police took action in 71 out of 129 cases passed to them, mostly in the form of warnings. Six out of eight cases were successfully prosecuted. The report says there is an "urgent" need to educate the building trade, which was involved in two-thirds of the detected cases. The network of licensed bat workers provides conservation advice, and conveys the issue to the public.

Dr Valerie Keeble, the chief executive of the trust, said the report painted a mixed picture of how Britain's mammals were faring. "It's very patchy," she said. "There is lots of good news for water voles, for instance, but the outlook for red squirrels does seem bleak, although we are making strenuous efforts to preserve them.'

She added: "I think we agree with the message of the report that we need much better monitoring of our British mammals. Bird numbers are now used by the Government to measure quality of life and I think mammals should be assessed in the same way to help us understand and appreciate our environment - after all, we are mammals too."

Under threat: Wildcat (Felis sylvestris)

Once found throughout Britain, wildcats are now confined to Scotland north of Glasgow and Edinburgh but are absent from the Scottish islands. Interbreeding with feral domestic cats has diluted its genetic strain to the point where experts now have trouble establishing what is a true "wildcat" which is eligible for protection under the Wildlife and Countryside Act. The report urges that wildcats be defined by their markings but that protection be extended to other tabby cats with similar markings to ensure preservation of the gene pool.

Reviving: The Water vole (Arvicolla terrestris)

Once found throughout Britain, the water vole was in serious decline due to predation from mink. But since more than 99 per cent of the population had disappeared by 1900 because of fragmentation of its habitat and competition from sheep, scientists believe the decline was inevitable. Carefully managed reedbed sites are helping to reintroduce water vole populations by providing them with safe a refuge from mink.

Under threat: Badger (Meles meles)

Badgers are widespread but are most common in the South-west, rare in East Anglia and Scotland. The report says that dry springs in 2002 and 2003 have cut the numbers of earthworms, their favourite food, and populations have dropped.

Reviving: Pipistrelle bats (Pipistrellus pipistrellus; P. pygmatues)

Populations of both these bats, once two of Britain's most numerous mammals, fell by 70 per cent between 1978 and 1993. But they appear to be increasing again, aided by a strong legal framework and a network of workers who monitor them

Under threat: Red squirrel (Sciurus vulgaris)

Absent from central and southern England apart from isolated populations such as Cannock Chase and the Isle of Wight. The report says extinction appears inevitable in England, Wales and southern Scotland.

Reviving: Otters (Lutra lutra)

Once confined to a small population in north-west Scotland, their numbers are rising after reintroduction schemes. They are now in Wales, East Anglia, the West Country and the Lea Valley, north of London. They also help keep down American mink.