This injured belted kingfisher was found on the JCCC campus during a bird-window collision survey. Window collision is the second-highest killer of birds (behind cat predation and not including habitat loss). Mortality increases significantly during migration, when artificial lights disorient birds, leaving them vulnerable to unsafe landscapes. This kingfisher survived. (Krystal Anton)
It mystifies me that while I sleep, millions of birds are passing silently overhead on a migration flight that can — for some of them — amount to tens of thousands of miles.
I’m fascinated by the instinct that drives them and the adaptation processes that prepare their seemingly fragile bodies to survive their arduous journeys. But I am frustrated, too, that these finely tuned processes have been inadvertently circumvented by human invention, leading to one of the highest causes of mortality birds can face during migration.
The positive news, however, is that it’s something we can fix.
As early as the 1800s, humans recognized the negative effects of artificial light on migrating birds. According to “A World on the Wing: The Global Odyssey of Migratory Birds” by Scott Weidensaul, lighthouse keepers reported large numbers of kills when migrating songbirds battered themselves against the glass.
In recent years, with the advent of radar technology, scientists have continued to witness behavioral changes. For example, Weidensaul writes that in 2016, scientists noticed a pattern in autumn migrants on the East Coast. Forest-nesting songbirds were found in increased numbers in urban parks.
Eventually it became clear that city lights were reshaping migration, especially in autumn when young birds on their first fights were being drawn by artificial urban light, which is “visible to a flying bird from as far away as 190 miles.”
The problem is that many birds navigate by starlight, and with the increasing sprawl of city lights, birds become disoriented. Once drawn from their migratory path, they become vulnerable to dangers, including window collision, the second leading cause of bird mortality behind domestic cats (and not including general habitat loss). While it’s true that these collisions occur year round, the numbers jump during migration.
“Spring migration is intense,” said Krystal Anton with the Center for Sustainability at Johnson County Community College.
In 2018, concerned with the number of dead birds being found on campus, Anton instigated a bird-window collision study to understand the extent of the problem.
“That first year was overwhelming,” Anton said.
By the end of the study, the JCCC team had found 287 dead birds, 42 injured birds, and 138 window imprints, which they believe had been left by birds hitting a window but not dying on site.
To date, volunteers at JCCC have found 94 different species that have fallen victim to collision. The species with the highest mortality rate during spring migration is the Swainson’s thrush. In the fall, it’s the ruby-throated hummingbird.
After accumulating her study’s results, Anton researched methods to decrease bird mortality on campus, and in 2019, the JCCC team began installing vinyl dots to the most problematic windows, breaking up their reflective surfaces to make them visible to birds.
“I tried different spacing, but placing dots every two inches has been nearly 100% effective in reducing collisions on the windows that have them,” Anton said. “It varies year to year, but we have about half as many collisions as we used to.”
Those statistics are heartening.
Across the country, an estimated 600 million birds are killed each year through collisions. Fifty-six percent of those kills occur against low-rise buildings, 44% occurs against residential windows, and 1% occurs against high rises — though their bird-per-building ratio is highest.
Often we look at issues we care about and believe there is nothing we can do, that we are helpless. But in this case, individuals can make a difference.
Lights Out Heartland, a collaborative of organizations working to reduce light pollution during migration, offers a list of ways to make our homes bird safe, some as easy as closing the blinds or changing bulbs in exterior lights. We can also encourage local businesses to get involved.
Thanks to radar tracking, cities can be alerted to when large flocks of migrant birds are entering a region, allowing participating entities to reduce their lighting, enabling flocks to pass safely.
“Reducing light pollution doesn’t mean you have to have it completely dark outside your home or business,” Anton said. “It’s dark skies not dark grounds. Better lighting with shielded lights that only shine downwards or motion detectors will take care of a lot of it.”
Many of us care about birds and are willing to help if we know how. Now we do. Migration begins as early as January for some species, but most will be traveling through Kansas between April and June, with May seeing peak migration. We can start making a difference today.
Shawna Bethell is a freelance essayist and journalist covering the people and places of Kansas, Nebraska and Missouri. Through its opinion section, Kansas Reflector works to amplify the voices of people who are affected by public policies or excluded from public debate. Find information, including how to submit your own commentary, here.
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