Leave a comment

Disease risk for wild birds from garden feeders

A study led by scientists from ZSL (Zoological Society of London) has found that garden feeders may be posing a risk of serious disease to wild birds.

Additional food is often left out for wild birds during harsh winter months, but the study has shown that while this can help, garden feeding can also promote the transmission of some diseases. Scientists found that risks were increased when birds were encouraged to repeatedly congregate in the same location, often bringing them into regular contact with other species they wouldn’t otherwise interact with. Stale food, food waste and droppings at the feeding station  further contributed to the risks.

The study was conducted over a 25 year period, in partnership with the British Trust for Ornithology (BTO) and Fera Science Ltd, who managed to identify the diseases responsible. Members of the public also contributed their findings via national ‘citizen science’ projects, which further helped scientists with their research.

Dr Becki Lawson 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”.

To minimise the potential risks associated with feeding wild birds a number of recommendations have been made by Garden Wildlife Health (GWH). People are encouraged to report seeing birds that are lethargic or with unusually fluffed-up plumage and consider a temporary halt to garden feeding in order to encourage birds to disperse, reducing the risk of further disease spread.

Kate Risely from BTO added: “We’re calling on everyone who feeds wild birds to be aware of their responsibilities for preventing disease. Simple steps we’d 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.

Anyone can join the battle against wildlife disease by contributing vital data to the nationwide GWH project. To find out more go to

Leave a Reply

Your email address will not be published. Required fields are marked *

* 7+3=?