For years, the mass of wintering birds at Kent’s RSPB marshes have attracted thousands of visitors during the colder months.

But now the effects of climate change are causing bird numbers to plummet rapidly and are putting the marshes at risk of becoming miserably barren.

Flocks of wintering water fowl and other species from the arctic region are noticeable by their absence at marshes in North Kent and Dungeness, as mild winters across the continent mean migrating birds do not need to travel as far as the UK’s south east for the climate they need.

RSPB warden for north Kent marshes said: “There are lower numbers of ducks, geese and birds of prey, as they are stopping over in Europe rather than coming here.

“The reserves have always been ‘sold’ on the spectacle of birds, but now people are not getting the same spectacle as numbers drop off.

“This could potentially affect the protection regulations on the marshland, which are given based on bird numbers, as people might not think the areas need special protection if they aren’t getting as much wildlife.”

At the Elmley Marshes on the Isle of Sheppey, the unpredictable weather caused birds to behave as if it was spring early, leading to possible food and habitation difficulties.

As a result, the number of wigeons – medium-sized ducks – has dropped sharply from nearly 10,000 to 2,000 and several species of migratory bird such as white-fronted geese and lapwing are almost totally absent.

On top of this, the results of the RSPB’s Big Garden Watch in January showed that the average number of birds seen in people’s gardens has declined by a fifth since 2004.

The society said blue tit numbers were particularly badly hit by the severe weather in Kent, with far fewer visiting gardens than in recent years. But the warmer weather saw finches on the up throughout Kent and the UK in general.

RSPB spokesman Hester Phillips said: “In Kent, it is not so much a case of which birds have disappeared, but which are disappearing or becoming greatly reduced in number.

“As ever with nature, there is no simple answer to why some species are declining and why some are increasing. Climate change maybe a factor but there are also other factors which must be taken into account such as loss of habitat due to increased development, lack of food, changes in gardening or farming practices or changes elsewhere.”