A naturalist and director of a company that helps fund the Beddington Farmland nature reserve has quit his role as a wildlife warden in protest of landowner Viridor's alleged "failure" to protect the site.

Peter Alfrey, who volunteers as a warden on the reserve, said the battle to stop the decline of the land's wildlife had been “lost in a catastrophic way”.

Related: Outrage at bid for incinerator next to Beddington nature reserve

Landowners Viridor, the waste giant that was granted permission to build an incinerator near the protected land, are responsible for funding the conservation groups that support the site’s wildlife.

But Mr Alfrey said the company was not doing enough to fund maintenance of the conservation site, and had broken promises in relation to the site becoming a public nature reserve as part of the planning permission granted.

Your Local Guardian:

Peter Alfrey, author of The Birds of Beddington Farmlands, is preparing to 'ship out

Breeding pairs of tree sparrows on the site had fallen from 80 to just one pair between 2010 and last year, according to data provide by the Breeding Bird Survey.

Radical changes to the model of conservation charities and their reliance on corporate funding is needed if nature reserves across the country are to survive, Mr Alfrey added.

He said: “The battle for Beddington Farmlands has been lost in a catastrophic way.

“The rest of the UK is next unless something radical changes and the conservation community remodels itself away from its reliance on corporate funding to survive, the same corporations which are destroying the environment on a catastrophic scale."

He added: “On a personal level I’m preparing to ship out.

"There’s not much more left for us [volunteers] to do.

“The work on the bird report and recordings were doing, everything we are putting into this is simply not being reciprocated and so on a personal level I am stepping back.”

The Sutton Guardian have approached Viridor for a comment.