Augustana professor does research on bird-window collisions

Staff Writer
Aledo Times Record

On Wednesday, Jan. 9,  PLOS ONE, an international, online scientific journal, published research on the unusual phenomenon of bird-window collisions (BWCs). Authored by Dr. Stephen B. Hager, professor of biology at Augustana College, Rock Island, Ill., the research article is called " “Window Area and Development Drive Spatial Variation in Bird-Window Collisions in an Urban Landscape.”

Dr. Hager, along with a small team of researchers and undergraduate students from Augustana, studied patterns of BWCs from randomly selected buildings constructed in a mix of habitats in a large city in northwest Illinois. Dr. Hager said, “We found that the number of collision mortalities was highly variable across the landscape, and the driving factors that influenced BWCs were the amount of windows in a building and proportion of development in which a building was found.”

He continued, “For example, BWCs were highest at buildings, such as offices, with lots of windows—about 50 fatalities in a year—and no fatalities were found at small houses. Also, BWCs were highest at buildings in green space and non-existent in highly developed areas.”

Previously published reports suggested that BWCs occur wherever birds and windows co-exist, and that more birds die from window collisions than any other human-related threat. The most widely cited estimate asserts that 1-10 fatalities occur each year at every building in the United States, which estimates more than 1 billion birds die annually.

Dr. Hager said the new research points out that BWCs may not be as widespread and common as is currently believed—that only a small number of vulnerable species are affected in high-risk areas, and the results call into question the utility of broad-scale estimates of BWCs, e.g., 1-10 collision fatalities per building per year.

“Applying an overall mortality estimate for one large city or the entire United States distracts us from understanding the complex nature of this issue, that is the driving factors that create patches of hot spot areas for collisions,” said Dr. Hager.

He added, “Despite these findings, we are obligated to reduce the impacts of windows on wild bird populations, and knowing of the driving factors of BWCs allows one to predict the magnitude of mortality for each building across the landscape. This is beneficial to bird conservationists because it allows them to focus conservation efforts in hot spot areas and ignore buildings that that pose little risk of BWCs.”

Dr. Hager believes urban planners could minimize future collision mortality by constructing buildings in areas away from green space, and architects could design buildings with windows and BWCs in mind.

Working with Dr. Hager on the research team was Dr. Bradley Cosentino, a 2004 Augustana graduate who now is a biology professor at Hobart and William Smith Colleges, Geneva, N.Y. Dr. Cosentino helped design the study and analyze the data.

Augustana students, including Kirsten Bjornson ’11, now in graduate school for neuropharmacology, worked as field technicians who surveyed the study buildings for carcasses resulting from window collisions.

Other contributors include Kelly J. McKay, Cathleen Monson, Walt Auurdeeg and Brian Blevins, local bird enthusiasts and experts who collaborated with Dr. Hager to design the experiment and complete the field work.

Published by PLOS, a nonprofit organization, PLOS ONE is a peer-reviewed journal that publishes reports on primary research from any scientific discipline. PLOS ONE is freely accessible online, offering fast publication times and community-based dialogue on articles.

For more information or to arrange an interview with Dr. Hager, please contact Keri Rursch, director of public relations, at (309)794-7721 or

About Augustana: Founded in 1860, Augustana College is a selective four-year residential college of the liberal arts and sciences. Augustana is recognized for the innovative program Augie Choice, which provides each student up to $2,000 to pursue a high-impact learning experience such as study abroad, an internship or research with a professor. Alumni include 140 Academic All-Americans, a Nobel laureate, 12 college presidents and other distinguished leaders. The college enrolls 2,500 students and is located along one of the world’s most important waterways, the Mississippi River, in a community that reflects the diversity of the United States.