Why it is vital to keep bird feeders and feeding areas clean?

After cats, the biggest reason for the premature death of garden birds is probably disease caused by dirty bird feeders. Some species of bird are particularly prone to disease, and top of this list would have to be the Greenfinch. A recent study undertaken by the Zoological Society of London, the British Trust for Ornithology, and Fera Science analysed over 25 years of data and found dramatic changes in some British bird populations, which scientists believe could have been caused by disease spread at bird feeding sites. However, it must be stressed that if the guidelines are followed, and bird feeders and feeding areas are kept clean, cases of disease will be rare.

Common Diseases in Garden Birds


The most common disease is Salmonella (Salmonellosis) and this is easily passed from one bird to another. Salmonella usually starts because husks are left to rot on the ground below a feeder, in particular black sunflower seeds, or if the feeder becomes clogged with waste or is just very dirty – therefore allowing the Salmonella bacteria to breed and spread. E-coli, also a bacterium, can also be a problem, but this is probably less common than Salmonella.


Trichomoniasis (Trichomonas gallinae) has long been present in Doves, Pigeons and birds of prey (though often not killing them) but in the last decade has spread to finches – again, in particular the Greenfinch – where the results have been more devastating, as once the bird has it, death is a certainty.Trichomoniasis is actually a single cell parasite which, once picked up by a bird through infected water or food, lives in the mouth and crop. The parasite causes lesions which eventually stop the bird swallowing and therefore leads to its death.

How to prevent your garden birds from catching diseases

Feeder Cleaning

The following simple steps and measures will ensure there is very little risk of any of your garden birds becoming diseased:

Keep bird feeders, tables & accessories clean

Clean all bird feeders, bird tables and accessories with a proper feeder disinfectant and do so on a regular basis – ideally once a week. If this isn't practical, then keep a supply of clean feeders so you can change them regularly and then clean all your dirty ones in one go.

Clear up husks

Clear up husks below feeders very regularly and ideally every few days (they can be put on a compost heap). If this time scale isn’t practical, then use a seed or seed mix which has no or very little husk such as sunflower hearts or high energy bird seed mix.

Use ground feeding tray

Use a ground feeding tray rather than putting food directly on the ground as it is easier to keep clean and if it isn’t eaten, clear it up and throw it away.

Throw away uneaten bird food

If food isn’t eaten in feeders, then also throw this away and clean the feeder thoroughly.

Change water regularly

Change the water in bird baths very regularly – ideally every day and in particular in the summer months – and clean the bird bath thoroughly using a special disinfectant. It is vital to ensure the bath is then thoroughly rinsed with clean water to ensure no disinfectant remains. Citrosan can also be added to the water to prevent disease occurring.

Change position of feeding area

Change the position of your main feeding area to somewhere else in your garden to prevent the ground below it becoming infected.

Wear gloves & wash hands

And don’t forget about your own health! Wear rubber gloves when cleaning feeders and bird tables, or if you need to handle a sick or a dead bird in your garden. Always wash your hands when you've finished any work to do with feeding birds and cleaning feeders.