Wildlife in Britain, already one of the world’s most nature-depleted countries, is continuing its long-term decline, according to the most comprehensive assessment ever carried out of UK biodiversity.

The State of Nature report, compiled by 60 conservation bodies in the public and charitable sectors and based on years of monitoring by thousands of volunteers, found that 16 per cent of the 10,000 species of plants and animals surveyed in Britain were threatened with extinction. This figure is much higher for birds (43 per cent) and reptiles and amphibians (31 per cent).

The study estimated that the abundance of the species studied — the number of individuals living in the wild — had declined on average by 19 per cent since 1970. But flora and fauna had already been highly depleted by human activity over previous centuries, so “the UK now has less than half of its biodiversity remaining”, the report said.

“The UK’s wildlife is better studied than in any other country in the world and what the data tell us should make us sit up and listen,” said Beccy Speight, chief executive of the RSPB, which co-ordinated the report. “What is clear is that progress to protect our species and habitats has not been sufficient, and yet we know we urgently need to restore nature to tackle the climate crisis and build resilience.”

The authors describe many actions that would help to revive biodiversity and achieve the government target of halting biodiversity loss by 2030. An estimated 70 per cent of Britain’s land area is agricultural, so the biggest single contribution will be “to implement nature-friendly farming at a much wider scale,” the report said. Farmland birds, which have declined by 58 per cent in 50 years, are in particular need of help.

Something else that “would make a huge difference”, said Richard Gregory of the RSPB, is “to make sure that the 11 per cent of the UK legally protected for conservation is really protected”.

“We have swaths of land, such as national parks and areas of outstanding natural beauty, that are not really being protected because the management is not up to scratch,” he said.