Cornwall Council has failed to report on conservation efforts at its important nature sites for the seventh year in a row, figures reveal.

Despite a government pledge to strengthen protection of biodiversity, experts warn consistent underfunding has left councils struggling to keep tabs on their natural sites – let alone protect them.

There are more than 40,000 so-called Local Sites in England, which the Department of Environment, Food and Rural Affairs defines as places with a "substantive nature conservation importance", because of the wildlife or geology they are home to.

Local Sites are different to Sites of Specific Scientific Interest – although Defra says many are their "equal in quality" – and councils do not have a legal duty to protect them.

However, government guidance says they should take the lead in partnering with local organisations to manage them, and must provide figures to Defra’s annual monitoring report.

But of the 149 councils asked to provide data in 2018-19, 62 (42 per cent) failed to do so – Cornwall Council among them.

The council has now failed to respond for ​the seventh year running.

The report notes many local authorities say they have insufficient resources to carry out assessments of their sites.

​In ​2011-12, the last year in which Cornwall Council submitted data, ​434 of the 619 Local Sites (70 per cent) in the area were being conserved.

Only 47 per cent of Local Sites across England are being conserved, according to the 2018-19 report.

Experts say years of cuts have seen funding diverted from discretionary services such as conservation, towards obligatory areas like social care.

David Lowe, head of ecology at Warwickshire County Council and a member of the Chartered Institute of Ecology and Environmental Management, said this meant some areas are inevitably "put on the back burner", and that "ecology has been one of these for many years."

The Government’s recent Environment Bill pledges to "strengthen the duty on public authorities to enhance biodiversity".

But Jason Reeves, head of policy and communications at the CIEEM, said it was "fantasy to think that it can be delivered without extra resourcing".

David Renard, environment spokesman for the Local Government Association, said any new burdens placed on councils "must be properly resourced", following significant budget cuts and increasing pressure in areas such as social care.

A Defra spokeswoman said: “Our Environment Bill sets out how we will protect our precious species and ecosystems, and local authorities have an essential role to play.

“We will work with them to deliver these measures and ensure any new costs are fully assessed and funded.”