The British Trust for Ornithology (BTO) issues guidelines for disease prevention at bird feeders and recommends bird food is purchased from accredited resources – but what on earth do they mean by ‘accredited resources’?


The BTO is “calling on everyone who feeds wild birds to be aware of their responsibilities for preventing disease. Simple steps we’d (BTO) recommend include offering a variety of food from accredited sources; feeding in moderation, so that feeders are typically emptied every 1-2 days; the regular cleaning of bird feeders; and rotation of feeding sites to avoid accumulation of waste food or bird droppings.”

The plea comes off the back of a collaborative study led by scientists from international conservation charity ZSL which suggests that wild birds are at risk of serious disease at garden bird feeders if hygiene at feeding stations is poor.

Commenting on the study, lead author Dr Becki Lawson MRCVS from ZSL’s Institute of Zoology said: “Our study shows how three of the most common diseases that affect British garden birds have changed both dramatically and unpredictably over the past decade, both in terms of the species they affect and their patterns of occurrence.”

“Both finch trichomonosis and Paridae pox have emerged recently, causing disease epidemics affecting large numbers of birds, while passerine salmonellosis – previously a common condition – appears to have reduced to a very low level. These conditions have different means of transmission – so deepening our understanding of disease dynamics will help us develop best practice advice to ensure that feeding garden birds also helps to safeguard their health”.

Simon King, Associate Director at Haith’s bird food (and Editor of the FFON blog) says the BTO should go a stage further and confirm what they mean by “accredited sources” as it’s vague. He says “Bird food companies must play a part in conservation and commit to providing high-quality, clean seed – to my knowledge, however, few of them are. Our research at Haith’s shows that dust, dirt and extraneous husk can damage a bird’s respiratory system and encourage harmful bacteria. We presented our findings to BIAZA and won an award for our SuperClean project. We do this for the birds and our friends who feed them.”

Blue Tit consuming a suet treat

Although the salient points made in this report are valid, much of the press coverage so far does not appear to say anything new explains Professor John E. Cooper, FRCVS, Specialist in Veterinary Pathology: “The changes recognised in some British bird populations may or may not be caused by the spread of pathogenic protozoa and bacteria (“disease spread”) at bird feeding sites. This report only states that “scientists believe” that the declines “could have been caused by disease spread” under such conditions; unequivocal evidence for this claim is not offered. Other factors could well be responsible, on their own or in combination, for the drop in numbers – as is the case in respect of the decline of many species of farmland bird. More detailed analytical research on the causes of morbidity and mortality of garden birds is needed.”

“The exhortation by the BTO for those who feed wild birds to be aware of their responsibilities for preventing disease is, again, not new. The “simple steps” recommended have long been advocated by veterinary surgeons, wildlife biologists and responsible suppliers of wild bird food. The reference to “food from accredited sources” is interesting. There is, as far as I am aware, no accreditation scheme for wild bird food and a search of the literature suggests that Haith’s is the only British company that has in place a proper quality assurance/quality control programme, with laboratory back-up, for such products.”

“The quotation attributed to Becki Lawson emphasises the point I make above – that we need more research before we properly understand the situation and can make valid judgements. In her words “…..deepening our understanding of disease dynamics will help us develop best practice advice to ensure that feeding garden birds also helps to safeguard their health”.

“In the meantime, in my view, the responsible feeding of wild birds should be encouraged,” says Professor Cooper.

We recommend a three-pronged approach to keeping feeding stations safe and healthy:

1) regular cleaning of bird-tables and other feeding areas

2) providing food of high quality (award-winning SuperClean bird diets)

3) not overfeeding birds, because they need to look for food in the garden and hedgerows, not to depend solely on human intervention.

See to browse Haith’s award-winning range of wild bird food and – more importantly – the work they do to ensure their bird diets are safe for birds and wildlife.