June 18, 2018
Yellow-rumped Warblers by Laura Finazzo
Feeding birds can be a great source of joy, but feeders can increase the risk of disease transmission in the birds we love if feeders are not cleaned adequately. What’s the best cleaning method to prevent the spread of disease? According to an article published in the March issue of The Wilson Journal of Ornithology, researchers at Kutztown University in Pennsylvania recently conducted a study to determine the most effective way to reduce levels of Salmonella enterica enterica bacteria on wild bird feeders.
The researchers gathered data from two sets of feeders: a set that had gathered debris from normal feeding activity and a set of unused, clean feeders. They applied cultures of Salmonella to the entire perch and seed well areas of each feeder and then measured the concentration of bacteria on the feeder. The researchers tested three cleaning methods: scrubbing feeders with soap and water, soaking them in a diluted bleach solution for ten minutes, and scrubbing them with soap and water followed by a soak in bleach solution. The feeders were tested again to determine how much bacteria remained.
The researchers found that all three cleaning methods reduced the amount of Salmonella on the feeders. However, in both feeder types, the two methods that involved a bleach soak were more effective in reducing Salmonella bacteria than simply scrubbing with soap and water. Additionally, they found that feeders with debris had more bacteria after cleaning than new feeders, regardless of the cleaning method used. Furthermore, the debris-laden feeders that received only the soap and water treatment still had enough Salmonella to risk disease transmission.
So what does this mean for FeederWatchers? We recommend that, at minimum, when you clean your feeders you soak or scrub them with a dilute bleach solution, rinse them thoroughly, and let them dry before adding bird feed. If your feeders have visible debris, be sure to scrub them as long as necessary to remove all visible debris before cleaning them. Remember that prevention is the key to avoiding the spread of disease and that you should regularly clean your feeders even when there are no signs of disease. For more information, visit our Sick Birds and Bird Diseases web page.
Feliciano, L.M., Underwood, T.J., and Aruscavage, D.F. (2018). The effectiveness of bird feeder cleaning methods with and without debris. The Wilson Journal of Ornithology, 130(1):313-320. DOI: https://doi.org/10.1676/16-161.1