
Pomona College Professor of Biology Nina Karnovsky is crying fowl about an overlooked issue in the avian world: Up to a billion birds in North America die from flying into windows each year.
Students in Karnovsky’s Advanced Animal Ecology class have been scouring Pomona’s campus for bird carcasses in the early hours of the morning, trying to make a tally of how many birds are dying after hitting windows on campus.
This week, the class found 14 birds, “which is actually a huge underestimate because [when] birds hit windows, they don’t always die instantly,” Karnovsky said.
The study has been a multi-year endeavor, Karnovsky said. It started as an independent project for some students in her class a few years ago.
For several years now, 5C students have come together under professor Karnovsky’s leadership to collect data during the birds’ fall migration season. This fall, several mornings per week, Pomona students will survey the number of dead birds they find near and around windows of buildings.
Zachary Wakefield PO ’22, one of Karnosky’s students and a biology major, told TSL that after going out Monday afternoon, he found three or four birds that had crashed into windows at Estella Laboratory. He found at least one bird on Wednesday and Thursday each.
Karnovsky added that there have been multiple reports of birds hitting the Dialynas residence hall glass walkway.
In addition to the data that Karnovsky’s students collect, the study relies on student participation. Wakefield sent out a call to the CHIRPS student newsletter asking Pomona students to email him with any reports of bird crashes.
It’s important that every bird who appears to have crashed is documented, even if they survive, according to Wakefield.
“Often, unfortunately, even if a bird flies away, it still dies or is eaten soon afterwards because it’s a little bit disoriented, or has even permanent brain damage,” he said.
The issue of birds dying from building interference is much more prevalent than people would think, according to Wakefield and Karnovsky.
Claremont and the surrounding area have a particularly high level of bird strikes, according to Karnovsky. Claremont lies on one of three heavy migration patterns for birds flying south for the winter, called the “Pacific Flyway,” which sees birds fly from Alaska, through Canada, and down through Southern California and beyond, she said.
According to Wakefield, past studies have revealed that around 40 percent of all window strikes occur on north-facing windows precisely because of these migrations, although the danger shifts to south-facing windows in the spring.
The problem is nationwide — window strikes are the second major leading cause of death for birds in North America, according to Karnovsky, exceeded only by predation by cats. While ecologists are aware of the issue, it’s difficult to pinpoint its magnitude. As Wakefield points out, there is no reliable central reporting system for window strikes across the country, posing a major barrier to data collection.
Last week, Pomona participated in an annual nationwide survey on bird strikes hosted by the Global Bird Rescue, which utilizes the Global Bird Collision Mapper to document data.
“Team Bird Strike 47,” as Karnovsky’s group named themselves, sent in all their collected data along with dozens of other organizations. The study will hopefully give both ecologists and the general public a better idea of the magnitude of the problem.
“We encourage you to search for birds in order to increase the chances of a successful rescue, but preventing these collisions is GBR’s ultimate goal,” the website said.
Although the larger study is over for now, Team Bird Strike 47 is far from done, and they are looking to propose innovative solutions to the problem on campus.
But Wakefield emphasized that he and others involved in the study are not advocating to remove buildings’ glass windows — there are “relatively simple modifications you can make to windows to reduce the frequency of window strikes,” he said.

Most cases of birds striking windows happen because birds see the reflection of plants or other external environments in a window and they don’t realize that the window is in front of them at all.
Ecologists who are trying to raise awareness around bird-building collisions recommend putting things in, on or around windows to disturb the reflection. UV decals, window pens, tape strips, screens and hanging objects are some of the common methods used to modify existing buildings, according to Wakefield and Karnovsky.
However, Karnovsky specified that ideal methods will break up the outside window reflection every three inches. She’s noticed singular decals on some windows around campus, which aren’t very effective, she said, but noted that there hasn’t yet been a coordinated effort to improve bird safety at Pomona.
“We’re going to try some experimentation to see what people like aesthetically but also what will keep the birds safe. And the migration is really not very long so this is like the time right now to protect the birds. And then when they come back up in the spring, then it’s the south facing windows we need to start worrying about,” she said.
Karnovsky added that turning off lights and drawing the blinds can have a huge impact on creating a bird-safe environment as birds navigate by the night sky, making them easily disoriented by light sources near windows.
GBR recommends bird-safe window products from Fatal Light Awareness Program Canada, which the biology department highlighted, along with Bird Safe Canada which provides information for making homes and commercial buildings bird-safe.
In August, Sustainable Claremont hosted a panel titled “Birds in our midst: Global impacts and local stewardship” which featured Karnovsky and Tina Stoner, the president of the Pomona Valley Audubon Society.
Wakefield emphasized his gratitude for the entire project as well as Karnovsky’s support.
“I think Professor Karnovsky definitely is very in favor of projects like this where you raise awareness [while] in the process of gathering that data,” Wakefield said. “You get more people to know about what’s happening and [it] can still be useful data to see, for example, what species of birds are most vulnerable.”
Karnovsky is confident that bird strikes can be reduced with some effort, pointing to the success of the Los Angeles Convention Center being built with bird-safe materials.
“This is something we can fix,” Karnovsky said. “It’s depressing, but it’s something we absolutely can fix.”
If students have any information on bird strikes or further questions, the bird window strike team can be reached at BirdStrike@pomona.edu.