Almost half of of Britain’s households are thought to put food out for the birds over winter, but a new survey warns that garden feeders could be putting wildlife at risk of disease.
Although putting out seeds, nuts and fat balls for garden visitors such as songbirds has helped boost populations during the winter months, badly kept garden feeders can be a danger.
According to a study by the Zoological Society of London (ZSL) and the British Trust for Ornithology (BTO), there is a great risk of disease if bird tables and other feeding stations are not kept clean, so stale food, food waste and droppings accumulate.
The report, which looked at 25 years of data on wild bird health threats, also notes that garden feeders can encourage birds to repeatedly congregate in the same location, and bringing them into contact with other species which they would not otherwise interact with in the wider environment.
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.”
She said two of the diseases had emerged recently, causing epidemics affecting large numbers of birds, while a third, previously common, condition had dwindled to very low levels.
As the three diseases had different means of transmission, tracking their occurrence could help develop advice that allows householders to deliver the benefits of feeding birds without putting them at risk.
Co-author Kate Risely from BTO said: “We’re calling on everyone who feeds wild birds to be aware of their responsibility 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.”