Among the most popular reasons that people feed wild birds is that they want to help birds. The extent to which supplemental food helps birds, however, is not well established. From spring 2011 to spring 2014, Millikin University faculty members Dr. Travis Wilcoxen, assistant professor of biology, and Dr. David Horn, professor of biology, led a study that explored how the feeding of wild birds influences the health of individual birds at forested sites in central Illinois.
The study compared three forested sites, where supplemental food was provided, with three forested sites where no supplemental food was provided and observed changes in the individual health of birds.
Data from wild birds was collected in 2011, 2012 and spring 2013. Students and faculty went back in spring 2014 after feeders were removed to see how the health of the birds had changed at the sites almost a year after the feeders were gone.
"It's a growing field – this research is the first of its type and it will likely make a huge impact," said Dr. Wilcoxen. "Dr. David Horn and I received a grant to pursue the question, how does the act of bird feeding impact the health of birds that use the feeders?"
The study showed a consistent pattern of greater overall health for the birds at the sites with feeders than those that did not. This was demonstrated by increased antioxidant levels, reduced stress levels, higher quality feather growth, improved body condition scores and a stronger immune defense system.
Dr. Horn noted, "The results of this study will benefit the people who feed birds and it will let them know that feeding birds can help the birds. Based on our previous study, 'Project Wildbird,' one of the reasons that people fed birds is that they wanted to help birds. With this publication, we can now demonstrate that bird feeding is helping."
Overall, over 1,500 birds from 11 species were sampled during the study. The sites used for the study included the Macon County Conservation District, Piatt County Forest Preserve and Weldon Springs State Park in Clinton, Ill.
Dr. Wilcoxen noted, "One of the important findings was that once the feeders were taken down we saw no evidence of a crash in the bird populations or their health. The birds were using the feeders as a supplement and not relying on them exclusively as a food source."
Click here to read more in an article from the Stevens Point Journal.