Do bird feeders spread disease?

This question has at times been debated in the media. Feeders, especially improperly maintained feeders, can spread disease. However, there’s no way to know if disease transmission at feeders is any less or greater than disease transmission in the wild. Birds that contract and spread diseases, such as salmonellosis, at feeders are typically social by nature and would aggregate whether at feeders or not. Nevertheless, to reduce the risk of disease at feeders, we encourage people to clean feeders regularly.