Hillarie O'Toole | August 7, 2024

Until a few years ago, I had never given a second thought to my apartment windows: they are rather mundane, standard-issue windows on a six-story building. Though I had volunteered with NYC Bird Alliance (formerly NYC Audubon) as a collision monitor for ten years and knew the staggering statistics of bird-window collisions, I always distanced myself from those numbers, envisioning high-rise office buildings and museums with their giant picture windows as the villains behind those bird deaths. 

But when I started working from home during the COVID pandemic, I was sadly reminded that even my boring little apartment windows pose a threat to migrating birds. One day I was startled by a loud bang when a White-throated Sparrow (Zonotrichia albicollis) hit my living room window. I ran down to street level hoping I’d find the bird stunned, but well enough to rush off to Wild Bird Fund for treatment, but tragically, the bird had been killed instantly. I understood then that I was indeed a part of the bigger picture. I logged the incident on dBird and was left to wonder: how many more birds had struck my windows over the years while I was at the office? 

The numbers tell a grim story. For over a decade, it was estimated that collisions kill between 365 million and 1 billion birds annually in the United States.” Today, new research by NYC Bird Alliance, Fordham University, and American Bird Conservancy scientists published in PLOS ONE suggests this number to be far higher, estimating over 1 billion birds die annually from collisions.

A window poses a menacing threat to birds, reflecting the trees and sky, presenting as a safe place to fly. People around the world were moved to speak out for bird safety after Flaco, the beloved Eurasian Eagle-Owl that escaped from the Central Park Zoo, met an untimely end, in part, due to a building strike on the Upper West Side, and through Flaco’s story, many are learning how to prevent similar tragedies in the future. 

As much as we love to talk numbers, human brains are not terribly good at comprehending impact on a massive scale. It is through individual stories that we can begin to understand the “butterfly” effect that the loss of just one bird can have on the ecological community. By zooming in on just one bird we might begin to understand the intricate connections and relationships that a bird’s life has within the ecological community—and understand the lives of birds within their own terms. Take for instance, the White-Throated Sparrow. What was missing from our world when that one bird’s life was cut short by my living room window?

The White-throated Sparrow is a charmer, the males easily recognizable with their sporty white stripes on their heads, yellow spot by their eye, and white patch on their throats. I always associate the familiar song, “Oh sweet Canada, Canada, Canada,” with my return to cycling through the park each spring. These small passerines winter across the contiguous US and breed mostly in the Northeast and Canada. In parts of New York and New England, they are known to be present year-round. Each pair typically lays 4-5 eggs per clutch and raises 1-2 broods per year. They feed their young a variety of insects: flies, caterpillars, ants, wasps, snails, and more. It is estimated that a small songbird can eat hundreds of insects per day, in addition to the insects they forage for their hungry young. Over winter, they feed primarily on the seeds of weeds and grasses. They forage for food on or near the ground and for that reason, may be particularly vulnerable to window strikes. According to the American Bird Conservancy, “the White-throated Sparrow has lost 93 million individuals since 1970.” They typically can live up to 6 years of age.

Just that one White-throated Sparrow’s death means there are likely up to 60 fewer White-throated Sparrows that will be born. Up to 5 million insects are left uneaten. Thousands of seeds of native grasses such as little bluestem (Schizachyrium scoparium) and flowers such as the woodland sunflower (Helianthus divaricata) are left undispersed, allowing more aggressive wind-pollinated invasive plants to take over the landscape. The loss of that one bird that struck my window means there is one less melodious song to waft on the breeze. A person passing through the park may never hear that joyous song that would have sparked their curiosity to learn to love the birds of NYC.

That same day, I sprang to action and ordered decals for my windows. Such an easy way to prevent bird collisions! I purchased them online and placed them on the outside of the glass, spaced the necessary two inches apart. Luckily my windows tilt inward for easy cleaning; always be sure to check with a building super to ensure safety when placing window decals. In the years following, I have not witnessed any more strikes, and guests frequently comment on the cute hummingbird decals adorning the windows. But mine is just one window of millions in Manhattan alone; we all must act in order to save one bird at a time.

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