An Experimental Test of the Effectiveness of Cleaning Bird Feeders in Winter
Student Researcher: Makayla Boyd, Undergraduate Biology Major
Sponsoring Faculty: Dr. Todd Underwood, Department of Biological Sciences
Project Description: Many people place bird feeders in their yards to provide birds with additional resources during the winter. However, few realize that bird feeders may actually be harming birds due to their potential to harbor diseases which could easily spread between birds. The Audubon Society recommends cleaning bird feeders in a 10% bleach solution once or twice a month to potentially decrease the spread of disease at feeders. The goal of the study was to test this recommendation by cleaning one feeder in each of nineteen pairs once every two weeks, while never cleaning the second feeder in each pair.
All of the feeders were sampled for bacterial and fungal levels. We found that cleaning feeders did not successfully reduce microbial levels on cleaned feeders compared to dirty feeders. Also, overall, the cleaned feeders did not display reduced microbial levels over time. Finally, microbial levels were not correlated to activity at bird feeders. These results indicate that cleaning bird feeders did not have the expected impact on microbial levels. Still, we recommend that feeders should be cleaned but only once every one to two months or sooner if they appear contaminated with fecal matter or dead birds are present near the feeders because this could be a sign of disease in the area.