Note: Natalia Ocampo-Peñuela can be reached for additional comment at (919) 348-3264 or Scott Winton can be reached at Nicolette Cagle can be reached at

DURHAM, N.C. – A student-led study at Duke University is inspiring action to reduce bird-window collisions on campuses nationwide.

The study, published today in the open-access journal PeerJ, identifies architectural and landscape features that contribute to collision deaths on Duke’s campus.

More importantly, says PhD student Natalia Ocampo-Peñuela, the study also details how the research team worked with university administrators and other members of the campus community to mitigate the harmful impacts.

Now, she says, groups from other universities and corporations are contacting the Duke team to learn how they, too, can go “from data to action” and reduce bird deaths on their campuses.

Flying into windows kills as many as one billion birds each year in the United States and accounts for an annual loss of between two and nine percent of North America’s estimated bird population. Migratory species, especially those that fly at night, account for most of the deaths.  

Many campuses pose a heightened risk because they feature wooded or landscaped areas surrounding low- and medium-rise buildings with large expanses of glass.

Graduate students at Duke’s Nicholas School of the Environment began conducting daily surveys around six buildings on Duke’s West Campus in 2014 to identify how many birds, and of which species, were being killed by flying into windows at each building during peak migration periods each spring and fall. To augment their survey results, the team also collected incidental data on collision deaths that occurred during other times of the year.

“What we discovered, not surprisingly, is that the buildings with the most glass, the highest percentage of glass to solid wall, and high amounts of surrounding forest cover killed the most birds,” says PhD student Scott Winton.

A more revealing finding, Winton says, was that buildings with collision-deterring patterned or fritted windows caused substantially fewer deaths than those with plain windows. This was true regardless of building size, height or proximity to wooded landscapes, and even if patterned or fritted windows comprised significantly more of the building’s exterior.

Armed with their findings, the researchers approached university administrators and asked them to take action to mitigate the collisions by having patterned films applied on windows responsible for the most deaths. Winton spearheaded passage of a resolution by Duke’s Graduate and Professional Student Council supporting these proposed measures, and the researchers also gave interviews to local television stations and newspapers to raise community awareness of the problem and its potential solution.

University administrators readily agreed to the measures. “They were very receptive to our findings and recommendations,” Ocampo-Peñuela says.  

By the end of summer 2015 workers had begun applying patterned films to four glass-paned towers and the outward-facing bridge facades at the 322,000-square-foot Fitzpatrick Center for Interdisciplinary Engineering, Medicine and Applied Sciences, the building responsible for the most collision deaths documented in the study. Printed dots on the film reduce reflectivity and visually break up the glass expanse for birds in flight while still maintaining 98 percent clear viewing for humans inside the building.

Since completing the initial phases of their ongoing study, Ocampo-Peñuela and her colleagues have heard from students at many other universities – as well as architects and managers at corporations such as Cary’s SAS Institute – who want to replicate Duke’s success.
“Our study gives them a scientific paper they can cite,” she says.

With the findings from the first phase of their research now published, the students have now turned their scholarly focus to finding answers to new questions, including quantifying the role weather plays in bird-window collisions and identifying which species are more vulnerable.    

Nicolette Cagle, a lecturer and trained ecologist at the Nicholas School, worked with the students on the study and is now leading a follow-up project to identify what traits make some bird species more prone to collisions than others.    

“There are so many times when research, especially student research, doesn’t necessarily result in real-world solutions, but this time it did,” she said. “It feels great to be part of that.”

Other authors of the PeerJ study were Charlene Wu and Erika Zambello, recent alumnae of the Nicholas School’s Master of Environmental Management (MEM) program, and current MEM student Thomas Wittig.


CITATION: “Patterns of Bird-Window Collisions Inform Mitigation on a University Campus,”  Natalia Ocampo-Peñuela, R. Scott Winton, Charlene J. Wu, Erika Zambello, Thomas W. Wittig, Nicolette L. Cagle, Feb. 1, 2016, PeerJ.; DOI