10
June
2019
|
06:44 PM
America/New_York

A deadly strike for migrating birds

Students aim to keep birds from flying into campus buildings

On a warm May morning this spring, Kandace Glanville walked past Mirror Lake on The Ohio State University campus, gingerly holding a paper lunch bag in her right hand.

She strode through dewy grass until she reached the edge of a small wooded area just west of Browning Amphitheatre. Glanville squatted, removed the paper clip securing the bag, and reached in. She pulled out a Bay-breasted Warbler, a tiny bird just 5.5 inches long, stunned from colliding with a window on campus earlier that morning.

She set it gently on the grass. The bird took two small hops and stopped.

“That’s not good,” Glanville said.

After waiting a moment, she picked up the warbler and put it back in the bag. “Maybe it just needs to rest a bit more. We’ll try again in a few minutes.”

***

Glanville, 22, graduated from Ohio State a few weeks earlier on May 5 with a degree in wildlife science, but she still volunteers with Lights Out Buckeyes, a project she helped launch last year.

Lights Out Buckeyes, sponsored by the Ohio State Ornithology Club, seeks to learn more about a serious threat to migrating birds throughout North America: window collisions. Each year in the United States, up to 988 million birds die by hitting windows, researchers say. That’s second only to predation by feral and household cats (up to 4 billion birds a year) as the largest human-related cause of bird deaths.

Bay-breasted WarblerMost window collisions occur during spring and fall migration, when more than 4 billion birds move between their breeding grounds in Canada and the northern United States and their winter homes as far away as South America. The “lights out” project title is a nod to a known contributor to window strikes: well-lit urban areas that attract migrating birds into unfamiliar settings full of dangerous obstacles.

Glanville and her fellow Ornithology Club members are assessing the scope of the problem on the Ohio State campus. How many birds are victims of these collisions? Are some buildings attracting more collisions? And, most important, is there any way to help prevent these usually deadly window strikes?

Glanville created Lights Out Buckeyes with Tyler Ficker, 21, another Ornithology Club member and wildlife science major who just finished his third year at Ohio State.

The impetus for the project came in spring 2018, when Glanville and Ficker talked about how many dead birds they were coming across on campus, especially during migration.

“From a research perspective, we were interested in how many birds we could find that had hit windows. And from a conservation perspective, we wanted to find out if campus buildings were a problem,” Glanville said.

So beginning last fall, a group of Ornithology Club volunteers scoured the campus twice a week during migration – from the start of autumn classes until Nov. 1 – usually collecting data from about 5 a.m. until their 8 a.m. classes.

The results, which she submitted as an undergraduate research thesis, surprised Glanville.

“We started out thinking we would find maybe 50 birds last fall. And then we documented more than 150 collisions. I was surprised by how many birds were being killed.”

In fact, the official tally for last fall was 173 birds, with 11 found alive.

During this spring’s migration, students started their campus building checks on March 1 and planned to continue until June 1. By mid-May, they had found 61 more birds, only two of which were alive.

***

Glanville had left her south campus area apartment at about 9 that May morning. She was going to Thompson Library to meet a friend who had found a window-strike victim that had not survived -- an Ovenbird, another type of migrating warbler. She decided to do a quick check around the Ohio Union for birds and spotted the Bay-breasted Warbler on the west side of the building.

“It was sitting up against the window, stunned,” she said. She pulled a net out of her backpack that she keeps for this purpose. “It didn’t even notice when I put the net over it. Didn’t care at all, didn’t move.”

She gently picked up the bird and placed it in the paper bag, put the paper clip on top, and left for the library. She met her friend and picked up the Ovenbird, which was sealed in a freezer bag. Then she headed to the wooded area to try to release the live bird.

***

The Bay-breasted Warbler that Glanville found had probably experienced an arduous journey even before it hit the Ohio Union window. Most of them winter in Panama, Colombia and Venezuela. They leave there in late April, flying at night to reach the boreal forests of Canada, where they breed. That means that Glanville’s stunned warbler had probably already traveled at least a couple of weeks and more than 2,000 miles by the time it reached Columbus – and still had a long way yet to go.

Mourning Warbler“These birds have to run the gauntlet to get to their destination,” said Christopher Tonra, assistant professor of avian wildlife ecology at Ohio State. “It still amazes me to this day that they are able to do that.”

The Bay-breasted Warbler weighs less than half an ounce. Being so tiny and having a high metabolism, they must feed voraciously on their diet of insects to have the energy to make the long migratory journey.

“For some of their big flights, they are eating enough to double their mass,” Tonra said. One of those flights includes a treacherous trip over the Gulf of Mexico that they must make without stopping.

“In the Midwest, we have created another ocean they have to cross, but this one is made of corn and soybeans. They used to have lots of opportunities to stop and refuel at forests across the Midwest, but there is now less available habitat,” he said.

“It can be hard for them to find the resources to complete their migration, even without the direct causes of mortality like window strikes.”

***

After not being able to set the Bay-breasted Warbler free, Glanville headed to Jennings Hall. There, Ohio State employee Sara Faust had a dead bird to be collected. Faust found the bird, an American Woodcock, a few days earlier in the building’s courtyard, which is surrounded by windows.

“Now that I know about you guys, I will keep a closer eye out,” Faust told Glanville. “We get a fair amount of window strikes.”

Faust led her to the top floor of the building where she had stashed the bird in what she called an “out of the way” freezer. “I didn’t want to terrify the TAs,” she said.

Glanville took the bird, thanked her and headed for the lobby.

***

Most window-strike victims are not Ohio’s familiar year-round resident birds like robins or cardinals or Blue Jays, said Matthew Shumar, program manager of the Ohio Bird Conservation Initiative (OBCI), which is based at Ohio State. It may be that these resident birds use the local landscape differently, resulting in fewer window collisions.

Most victims are migrant birds just passing through, Shumar said. Nocturnal migrants see the lights of the city while flying high above and get confused for reasons scientists don’t completely understand. “Lights draw migrants into urban areas where they would not normally stop,” he said.

Only some fly directly into the buildings at night. Many collisions appear to happen right after sunrise. “The sun comes up, birds see reflections of adjacent green space in windows, and that is when we see most of the collisions,” Shumar said.

The OBCI has started “lights out” programs in seven Ohio cities, with the goal of getting as many buildings as possible to reduce unneeded lighting, especially during migration season. Less lighting draws fewer birds to the cities, reducing window-strike deaths. These “lights out” efforts are occurring throughout the country and have succeeded in reducing window strikes.

“There was an 80 percent reduction in bird deaths at a site in Chicago simply by reducing the lighting throughout the city,” Shumar said.

Other solutions include special window treatments that reduce reflectivity or make it obvious to birds that the windows should be avoided. Those solutions can be more expensive, though, he said.

***

Lights Out Buckeyes volunteers are only beginning to get a handle on how many birds strike windows on campus, but they say it is larger than any of them expected. Ficker, the co-founder of the project, can vividly recall one particularly bad day last fall.

Tyler Ficker“It was Oct. 26. We found 18 dead birds that day. We knew we would have bad days, but I never thought we would have a double-digit day,” he said. He recalls another early morning last fall when a Lincoln’s Sparrow hit a window on the Ohio Union as he was standing there.

Even on days when they don’t do an official check of campus, volunteers often will look for birds when they have a few minutes. On one May day – not the same one on which Glanville found the Bay-breasted Warbler – Ficker did a quick 20-minute late-morning tour of a few buildings on campus and picked up five dead migrants: a Palm Warbler, Tennessee Warbler, Gray Catbird, Rose-breasted Grosbeak and Cedar Waxwing.

Ficker compiles data for Lights Out Buckeyes, maintaining a detailed spreadsheet with information on every bird they find. Included is not only where the bird was located, but also on what side and how far from the building it was found. Volunteers also note if the building lights were on and collect information on the sex and age of the bird, if it can be determined.

Dead birds are taken to Ohio State’s Museum of Biological Diversity, where they are kept as specimens for study. The few live birds they find are usually transferred to the Ohio Wildlife Center in nearby Powell for rehabilitation and release – unless they can be released on campus after a short rest.

With Tonra as his adviser, Ficker is writing an undergraduate research thesis this year that will examine which buildings on campus have higher collision rates and determine if they have common characteristics.

Volunteers already know some buildings seem to attract more collisions, such as Thompson Library, the RPAC, Blackburn House, the Ohio Union and Dreese Laboratories. Some of these building seem to have obvious dangers, such as wide expanses of windows, but others don’t. And not all buildings with a lot of windows seem to have a lot of collisions.

***

Despite the many birds students are finding, many more are probably being missed, Shumar said.

“Trying to figure out how many birds actually hit windows is a really complicated issue. There are issues with scavengers, like cats, raccoons and opossums. And cleaning crews, too – they often get to the birds before we do,” he said.

Kandace GlanvilleThe building coordinator for Pomerene Hall, Matt Hughes, bears this out. Like many coordinators, Hughes didn’t know about Lights Out Buckeyes and their offer to collect window-strike victims, so he has disposed of dead birds found outside his building. He said he collected at least six dead birds this spring.

There were 571 buildings on the Columbus campus in 2018.

Eventually, Lights Out Buckeyes hopes to gather enough information to offer potential solutions to the window strike problem at Ohio State.

Kevin Perozeni, a student who just finished his second year as a wildlife major, is doing an undergraduate research project based on Lights Out Buckeyes, just as Glanville and Ficker did. His focus will be finding strategies to reduce the number of window strikes. He hopes to test some experimental solutions – for example, comparing the number of collisions at buildings with lights turned off at night during migration to similar buildings that stay lit.

“I hope to gather enough evidence to show not only that this is a real problem, but also that there are real solutions,” Perozeni said.

***

When Glanville left Jennings Hall after picking up the American Woodcock, she decided to try to release the Bay-breasted Warbler again near the same woodlot on campus. But she wasn’t holding out a lot of hope. “I don’t feel any movement in the bag,” she said.

When she arrived, she put the bag on the ground and unfolded the top. This time, the bird immediately flew out and into the lower branches of a nearby tree. Glanville walked closer for a look. The bird sat motionless for the few minutes Glanville watched, but she took it as a victory that the bird flew off on its own.

“It doesn’t look 100 percent, but it did fly. Maybe it will be OK after all.”

If you find dead birds on the Ohio State campus during fall or spring semester, email Lights Out Buckeyes at osubirds@gmail.com.

To learn more about preventing window collisions, go to the Glass Collisions webpage from the American Bird Conservancy.