Collecting Casualties: Monitoring bird-building collisions

White-throated Sparrow Image: Keith Olstad

Oh, buddy,” I sighed, as I knelt over the tiny bird. It was the first week in October, during peak migration, when millions of birds pass through the Twin Cities, heading south along the Mississippi Flyway. I was part of a team of citizen scientists who’d signed up for the annual Global Bird Rescue (GBR) bird-strike count. Our task: to find birds that had crashed into buildings and dropped out of the sky. My assignment was the area around the Minneapolis Convention Center.

I picked the bird up off a pebble pathway that ran beside the glass-fronted building. The pops of yellow between its bill and eyes, and the tell-tale white bib around its throat told me all I needed to know: I am holding a White-throated Sparrow.

It is known as a plump, rather large sparrow, though it weighs less than an ounce. Still, it felt substantial. Its warmth radiated through my glove. Had it crashed just before I happened on it, before its heat and life force had time to escape? It was so perfectly intact, I swear, it looked alive. Yet I knew: It was deader than a doornail. To the ornithologists who will study it, this bird was now a specimen. Its loss felt heavy.

I set the bird down, took its picture, and downloaded it onto the GBR app, an online geo-mapping tool designed for reporting the locations of bird-building collisions. The app notes the precise location of the collision to help identify the highest risk areas for birds. It includes a checklist of questions including its status as dead or alive, and if dead, was it fresh or decayed, or even predated? When I clicked send this blip of data joined thousands more blips that together may tell a story about the fate of this year’s migrating birds. Lastly, I slipped the bird into a plastic bag, which I would store in my freezer, before delivering it to researchers who will study it, so that its death will not be for nothing.

***

 Earlier, we’d gathered on Zoom for our marching orders. Marian Weidner, Chair of Audubon Chapter of Minneapolis, pulled from her backpack the things we’d need to carry: binoculars to scan the environs for easy-to-miss birds; disposable gloves; plastic bags; notebook; hand sanitizer. Marian also carried small cardboard cartons—the kind used for Chinese take-out—to contain small injured birds, and a pillow case to cover and calm larger birds, for transporting to the Wildlife Rehabilitation Center (WRC).

She said the eyes of injured birds might be swollen; their legs outstretched; their head turned round. A bird may appear stunned, or may even be hopping around, inciting hope for rehabilitation. But window strikes can cause irreparable internal damage, and despite our best efforts, most injured birds do not survive.

An injured Ruby-crowned Kinglet after a window collision. Image: Wildlife Rehabilitation Center

***

Our days started at dawn, before street sweepers had time to collect the evidence.

On day one, I found 11 casualties. Some were crawling with maggots. Their eyes were desiccated, their feathers mottled, their twig-thin legs splayed out in improbable arrangements. They’d been there a while. The rest of the week, the kill was fresh. Though some were a bit roughed up and bloody from impact, many, on first glance, appeared perfect. They might have been napping, that is, if birds were to sleep on their back or sides on a pebble path beside a glass wall.

***

Why sign up for a week of sadness? Because the birds that piled up in my freezer—the specimens—may hold answers to the survival of their species.

“A dead bird has so much useful information in it,” Sushma Reddy, an ornithologist at the University of Minnesota’s Bell Museum, told our team. They reveal information on diet, movement, and environmental conditions, such as exposure to heavy metals or pesticides, which is how we learned about DDT, she said. Their data can lead to policy solutions, such as lights out, and bird-friendly glass. Data can inspire coalitions, such as the one our team has formed to advocate for safer conditions for birds.

***

 Most migratory songbirds travel at night, relying in part on the moon and constellations to guide them. Night flying has other advantages: less turbulent air; cooler temperatures; fewer predators. There is, however, a lethal disadvantage: artificial light. It confuses birds. Drawn to the light, they crash into houses, office towers, transit shelters, car windows, greenhouses, solariums, and skyways.

 Daytime poses other dangers. Birds fly into the reflection of trees in glass, perhaps looking for a place to perch. Or they attack their mirror image, mistaking it for a predator. Or they fly straight through glass so clear they never knew what hit them.

Day or night, birds crash and fall. The built environment is deadly.

***

“Are birds stupid?” a TV news reporter asked. He and his cameraman followed me one morning as I scoured the grounds for dead birds. It was a sincere question. After all, shouldn’t birds have caught on to the dangers of particular routes?

 Keith Barker, an ornithologist at the Bell Museum, explained it like this: "These animals evolved in the absence of bricks and glass. And those are substances that they [birds] aren't used to seeing in their environment.”                      

Click image for clip of author’s interview during Global Bird Rescue.

***

We can stop the death spiral. We know that building collisions are among the top human-generated threats to birds. So, we advocate for “bird-friendly” glass in new or retro-fitted construction.

And we advocate for turning lights out during peak migration. The consequences of inaction can be horrific. In Chicago, a convergence of strange weather, an unusually large migration, and human negligence sparked a freak event the same week as the Twin Cities GBR count. In a single day, some 1,000 migrants flew into McCormick Place, a sprawling, glassy convention center on the shore of Lake Michigan. Although the building owners had pledged to turn out the lights during peak migration, that night the lights stayed on.

Field museum staff collects bodies of birds that have collided with windows. Image: Lauren Nassef via the Field Museum

We can hold people accountable for such inaction. Conservationists responded to the McCormick Place debacle by asking the US Fish and Wildlife Service, which enforces the Migratory Bird Treaty Act, to fine the building’s owners for violating the act, which essentially protects birds from people. They asked that the money be directed to advocating for a stricter lights-out policy during migration season. “When saving the lives of 1,000 birds is as simple as flipping off a light switch, it’s unconscionable to require anything less," said Tara Zuardo, a senior advocate for the Center for Biological Diversity.

***

One morning, I saw three White-throated Sparrows fluttering around a corner where two glass walls adjoined. They kept flying straight toward the glass, determined to reach something, perhaps the reflection of a nearby ornamental tree, or maybe their mirror image. They flew at shoulder height, hovering in mid-air, before dive-bombing the glass. I waved my hands and shooed them away. They persisted. I waved again and the birds took off. When I left, did they return? Next morning, would I find them on the ground?

If only we can spend our days frantically flapping our hands, redirecting birds, like the friendly police officer who stopped traffic for Mrs. Mallard and her eight ducklings, as they made their way from their island nesting ground, to the Boston Public Garden, where Mr. Mallard awaited them. Make way for ducklings! And they all lived happily ever after.

There were no happy endings for the birds I gathered in early October. In all, I bagged 31 casualties; our team collected 169.

Bird by bird, the casualties pile up. American Bird Conservancy reports that each year up to 1 billion birds die after hitting glass surfaces in the United States.

***

The count week was over when I found a bird on the sidewalk near a building on the edge of a city park. It lay beneath a large pane of glass that juts out two stories high, as if suspended in mid-air. This glass doesn’t function as a window, that is, as a barrier between inside and out. It’s a frivolous, deadly architectural flourish. If I were a bird, I’d fly right through it. In a fit of avian confusion, I’d crash and fall out of the sky. I dare anyone to ask: Are you stupid?

I cried as I held it—another White-throated Sparrow—in my hand. Then I recalled what Sushma Reddy had told our team, and what I told the reporter: “A dead bird has so much useful information in it. It’s actually why we go out and do this really sad project.”

    -Miriam Karmel 

A widely published journalist and freelance writer, Miriam Karmel is the author of Being Esther. Her work has been published in AARP The Magazine, Minnesota Women’s Press, Bellevue Literary Review, and Minnesota Monthly. She lives in Sandisfield, Massachusetts and Minneapolis.