January 15, 2016 at 10:15am
Dane Lisser

The Impact of Wild Bird Feeding

Results of a study conducted by faculty and students from Millikin University's biology department have been published in the journal of Conservation Physiology. The research examines the effects of bird feeding activities on the health of wild birds.

From spring 2011 to spring 2014, Millikin 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.

Wild Bird Feeding

"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 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.

"Millikin had the opportunity to take the research we did with a previous study, 'Project Wildbird,' and ask what's next?" Dr. Horn said. "Essentially, it solidifies Millikin University's position as a national leader in the study of one of the most popular hobbies in the United States."

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.

Wild Bird Feeding

"We had a four year data collection period during which we had 14 Millikin students work on the project and eight of the students ended up being co-authors," said Dr. Wilcoxen. "We tested a number of different things and used different metrics in the study that people never used before with wild birds."

Millikin faculty and students determined that the individual health of birds improved with supplemental feeding, including reduced stress and rapid feather growth. Both positive and negative impacts of wild bird feeding were found, and birds that had access to supplemental food were in better physical condition. Additionally, the negative effects that were found, such as increased disease among birds, may be lessened by hobbyists engaging in safer bird feeding practices.

The study answers a lot of previously unanswered questions in this field and we feel that this is a great culmination of what we've done.

Wild Bird FeedingDr. Horn added, "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."

In terms of the research being published, Dr. Wilcoxen says, "It will be open-accessed and I think this is exactly the level we were hoping for when we started this study. The study answers a lot of previously unanswered questions in this field and we feel that this is a great culmination of what we've done."

The study also provided performance learning opportunities for several Millikin students to present their findings at national and international conferences.

Cody Hubble '13, a biology allied health track graduate from Millikin, was one of the students who worked on the project. "It was a very enlightening experience for me. We drew blood from birds and took body measurements, and it was a great opportunity to learn how to do research and how to conduct yourself in the lab," Hubble said.

Hubble is currently in graduate school studying physical therapy and he credits Millikin University for his research preparation. "Writing a research paper, looking up articles, and time management were things I learned during the wild bird study. I found myself ahead of the curve with research experience when I started graduate school."

Wild Bird Feeding 

The research was supported by the Wild Bird Feeding Industry Research Foundation, The Scotts Company, Siemer Enterprises, Millikin University, Decatur Audubon Society, Illinois State Academy of Science Undergraduate Research Grant, and Sigma Zeta National Math and Science Honor Society Student Research Grants.

Click here to view the published results of the wild bird feeding research conducted by Millikin University.