Dirty bird feeders risk spreading dangerous diseases to wildlife, says the RSPCA, which is appealing to bird-lovers to be extra vigilant with cleaning in their gardens this winter.

With bird flu still spreading among wild animals and calls to the welfare charity about sick birds reaching almost 9,000 last year - inspectors are trying to do all they can ahead of the coldest months of the year to protect the health of both garden bird populations and other creatures.

And as autumn turns to winter - and bird lovers are expected to step-up the amount of extra food they offer to those coming through their gardens - the RSPCA says households must equally be aware of just how vulnerable small creatures can be to ill health.

In 2021 there were 8,750 calls to the charity about sick or weak garden birds - including 276 reporting problems in Kent.

Ground feeders such as wood pigeons and blackbirds and those that use hanging feeders such as sparrows and finches were regularly among the reports of unwell birds people had come across in their garden.

With the RSPCA’s helpline already expecting to struggle with an unprecedented high volume of calls this year as the charity faces a very high workload brought about by the cost of living crisis, instilling people's help in maintaining the health of garden birds has become an even greater priority.

While bird flu tends to affect sea birds and water fowl more than garden birds, welfare experts say the current outbreak serves as a timely reminder about just how easy contagious diseases can spread between populations when they mix.

RSPCA scientific officer Evie Button explained: "Birds can die from diseases caught from dirty feeders and water bowls so it’s really important to keep garden bird feeders clean.

"It’s really heart-warming that so many people - around half the population - want to help garden birds by feeding them. But data suggests that birds are not as healthy as they should be and one way we can make a difference and keep them disease-free is good hygiene.

"While bird flu - a terrible disease which is currently sweeping through our waterfowl and seabird populations - thankfully doesn’t tend to affect garden birds very often, it’s a timely reminder of the devastation that can occur from a highly contagious disease.

"As supplementary feeding does encourage birds to gather together in close proximity, it can create ideal conditions for diseases to spread amongst garden birds. By regularly cleaning bird feeders we can all do our bit to help stop the spread of devastating diseases and maintain the health of our garden birds."

With around half of all households likely to leave some form of food out for the birds this winter the RSPCA is issuing new advice about cleaning up.

Alongside cleaning feeders weekly and water containers daily - including rinsing with clean water and drying before refilling - other suggested tasks include rotating feeding areas or tables around the garden in order to stop bird droppings and bacteria from building up in one particular place.

Feeding areas where possible should also be raised above the ground in order to deter mice, rats and other unwanted visitors that will also be carrying their own infections and diseases.