More than half of Surrey's wildlife is in decline.

That was the stark warning delivered today in a groundbreaking study by experts from leading conservation and research organisations.

The State of Nature report, due to be launched by Sir David Attenborough and UK conservation charities at the Natural History Museum in London this evening, has been put together by scientists from 25 wildlife organisations as a stock take of our native species.

And one of the findings of the study – the first of its kind in the UK - is that Surrey's wildlife decline mirrors the national slump in UK species.

The report reveals that 60% of the species studied have declined over recent decades. It also states that more than one in ten of all the species assessed are under threat of disappearing from our shores altogether – a trend worryingly mirrored in Surrey and across the South-east.

The report flags up the disappearance of heathland in Surrey as a key example of the plight of the nation's wildlife.

In Surrey, Hampshire and Berkshire, the areas of heathland, now collectively known as the Thames Basin and Wealden Heaths, are home to a range of specialist heathland wildlife, including smooth snakes, sand lizards, Dartford warblers and many butterflies and dragonflies. However, over the years, much of this habitat has disappeared and what remains is often fragmented into isolated pockets which have become the last place in Surrey where you can find many key species in decline such as the red barbed ant and heath tiger beetle.

The report states that where heathland is appropriately managed, the wildlife that relies on it can thrive locally.

But it adds that all too often these species are confined to a very small area of suitable habitat, and are restricted from expanding their numbers because of habitat fragmentation. It stated: “This makes them incredibly vulnerable and susceptible to population crashes or even localised extinctions.”

The story of the Dartford warbler is a case in point.

Arguably Surrey's rarest bird, it was spotted by excited birdwatchers on Reigate Heath several years ago, but since then its numbers have plummeted because of severe winters and a spate of summer heathland fires, including on Reigate Heath.

Last year, the Rare Breeding Birds Panel (RBBP) reported that the heathland bird “has suffered a dramatic population decline at some of its most important breeding sites in South-east England.” It was reported that there was only believed to be 50 pairs across areas of Surrey, Sussex, Berkshire and Hampshire. Chris Corrigan, South East regional director for the Royal Society for the Protection of Birds (RSPB) , said: “The South-east’s wildlife reflects the declines that this new report highlights.”

He said: “The region has consistently shown the greatest declines in both the farmland and woodland bird indicator lists and there is nothing to suggest that these declines are slowing.

“From the mudflats and grazing marshes of North Kent through the downland in Sussex and the heathland of Hampshire and Surrey, wildlife is under threat.”

He continued: “The South-east is the country’s economic powerhouse and this puts extra pressure on our natural environment.

“The RSPB, together with a whole range of other conservation bodies and, perhaps more importantly individual landowners, is working hard to protect the wildlife that we have left – and make sure that it is around for future generations to enjoy. “This may not be a new message but it is as important as ever, and now there is compelling new evidence that it is even more urgent and that concerted efforts will be needed if our wildlife and our countryside are to be properly protected.”

Sarah Jane Chimbwandira, director of biodiversity at Surrey Wildlife Trust, said: “In Surrey, the challenges being faced by our wildlife remain significant, and the report is a timely reminder that despite some recent successes there is a considerable amount still to do.”

She said: “For example, there are over 270 priority species across the county that are in national decline. “The iconic heathlands in the west of the county, themselves a surviving fragment of what was once an extensive habitat, are often the sole repository for many key species in decline, such as the red barbed ant and heath tiger beetle.”

Jim Foster, conservation director for Amphibian and Reptile Conservation, said: “Twelve out of Britain’s 13 native amphibian and reptile species live in Surrey.” He said: “Although the natterjack toad became extinct and the sand lizard just hung on in the 1970s, dedicated conservation work and reintroduction programmes are helping to secure their place in the county.

“But the more widespread species need help too. Whether in gardens, parks or the countryside, the loss of habitats through development, changes in land use and unsympathetic management has severely affected these animals across the county.”

Heathland once covered vast areas of southern England.

However, since the 1800s, forestry, agricultural intensification and urban development have contributed to the loss of 75% of it.

Heathland continues to face significant threats, despite intensive conservation action over the last 20 or more years. But the State of Nature coalition of groups has said there is significant potential to restore heathland where it has been lost relatively recently, making sites bigger and reconnecting them, which makes dependent wildlife more resilient to the pressures of a changing environment.

“Declines are happening across all habitats and species groups, although it is probably greatest amongst insects, such as our moths, butterflies and beetles,” the wildlife experts stressed in a joint statement. “Other once-common species like the lesser spotted woodpecker, barbastelle bat and hedgehog are vanishing before our eyes.” Chris Corrigan concluded: “None of this work would have been possible without the army of volunteer wildlife enthusiasts who spend their spare time surveying species and recording their findings.

“Our knowledge of nature in the UK would be significantly poorer without these unsung heroes - and that knowledge is the most essential tool that conservationists have.”

Sir David Attenborough said: “This groundbreaking report is a stark warning – but it is also a sign of hope.

“For 60 years I have travelled the world exploring the wonders of nature and sharing that wonder with the public. “But as a boy my first inspiration came from discovering the UK’s own wildlife.”

He said: “Our islands have a rich diversity of habitats which support some truly amazing plants and animals. “We should all be proud of the beauty we find on our own doorstep - from bluebells carpeting woodland floors and delicately patterned fritillary butterflies, to the graceful basking shark and the majestic golden eagle soaring over the Scottish mountains.

“This report shows that our species are in trouble, with many declining at a worrying rate.

“However, we have in this country a network of passionate conservation groups supported by millions of people who love wildlife. “The experts have come together today to highlight the amazing nature we have around us and to ensure that it remains here for generations to come.”