Blue Ridge Country Nov/Dec 2024 - 53

box. For the last few years, Richard and
his wife had enjoyed a screech owl singing
them to sleep, and he had just built a
nesting box in appreciation. As a lifelong
birder, he knew that screech owls don't
craft nests of twigs and twine. They're
cavity nesters who tend to find already
established holes in trees. So in places
where mature trees have fallen to development,
owl boxes can be helpful.
After Richard put the box up, he'd
waited for owls to take him up on the
offer of shelter. And he'd waited-and
waited. Then, just before that streetlight
went back on, a screech owl pair
had shown up. It's common practice
for owls to house hunt before settling
down, so the light had particularly bad
timing. The relationship he'd worked to
establish was acutely threatened. The
new bulb was, like almost all newly installed
bulbs, a white-light-emitting diode
(LED). And, like many LED lights,
it produced blue-rich white light. This
type of light isn't just the most damaging
for astronomers' sight; it's one of the
most biologically confusing for wildlife,
since animals read blue light as a signal
to enact daytime behaviors.
Astronomers tend to think of light not
in generalities, but by wavelength: Red
waves are long and easygoing, blue are
short and energetic. We might dismiss
sunlight as a generic white, but it's violet
and blue and green and yellow and orange
and red. We're surrounded by rainbows
every day, we just can't always make
out light's diversity-mainly because blue
wavelengths are particularly pushy.
When animals are blasted with blue
light at
night, their bodies naturally
read it as daylight. This is why, with an
increase in light pollution, biological systems
three billion years in the making are
starting to misalign. Animals get amped
for their respective activities out of sync.
Artificial light literally puts us on different
wavelengths.
In contrast, warm-tone spectra tend
to be read by animal bodies for what
they are: more easygoing energy. Campfires
and old-fashioned incandescent
bulbs tend to pool light where they're
located. But even in situations where
streetlights point downward, as responsible
guides suggest, blue light tends to
ABOUT THIS STORY
T
his story is an excerpt adapted with permission from
Leigh Ann Henion's recently published book, " Night
Magic: Adventures Among Glowworms, Moon Gardens, and
Other Marvels of the Dark " (Algonquin Books). In " Night
Magic, " the owls ultimately have a happy ending.
Henion is also the author of " Phenomenal: A
Hesitant Adventurer's Search for Wonder in the
Natural World. " Her writing has appeared in The
New York Times, The Washington Post, Smithsonian and a variety of
other publications. She lives in the mountains of North Carolina.
For more information: leighannhenion.com/books.
bounce skyward.
Advanced LED bulbs provide more
light with less energy. This has led to nearuniversal
adoption of blue-rich LEDs,
though the technology is capable of other
colors. Life scientists generally agree that
LEDs with high blue content have larger
biological impact than the bulbs that
came before them. And the potential energy
conservation of using this technology
has largely been negated
by human behavior. Instead
of using less energy after
switching to LED lights,
people have, the world over,
started using even more
energy for ever-brighter illumination,
as if we've collectively
decided that, since
the light is energy-efficient,
we might as well produce more of it.
Many news stories about light pollupopularity
of glasses with blue-blocking
lenses grew. We know blue light is harmful,
but it seems impossible to get away
from it. After all, when Richard stepped
away from his computer on that first
LED-lit night, he found that
the same
blue spectra that he'd been trying to take
a break from had swallowed his entire
house from the outside.
He'd planned to watch the miracle
of owls' seldom-observed
life
cycles unfold with
Screech owls
prefer established
cavities for nesting,
particularly those in
dark places.
the same close attention
that he gives young stars
through telescopes. Now,
every tender act
he'd
hoped to witness was under
siege. Frantic to find
an off switch, he started
making calls. To public
tion present it as having increased roughly
50 percent over the past 25 years. But people
familiar with satellite technology have
brought to attention the fact that some of
the equipment that's been used to gather
data is not sensitive to blue wavelengths,
which are on their way to global domination.
With blue-rich LEDs taken into consideration,
some scientists suggest that, in
certain places, artificial light pollution has
more realistically increased 270 to 400
percent during the past 25 years.
Interestingly, as outdoor blue light has
proliferated, literally under radar, our
awareness of it indoors has increased.
During the pandemic, when nearly every
interaction with people outside of a given
household was conducted via screens, the
officials. To neighbors who might help
him create an uproar. But in the end, no
uproar was needed. Once administrators
learned that a brooding pair might be disturbed
by the streetlight-which they'd
thought, if anything, human residents
would consider an upgrade-workers arrived
within 74 hours to remove the bulb,
returning the neighborhood to the level
of darkness it had previously enjoyed.
Municipal administrators had been
trying to do the right thing with those
LEDs. They had crunched facts and figures,
but they had not absorbed the true
cost of pelting energy against everything
in the streetlight's radius. Unfortunately,
the town's quick response was still too
late. By the time the streetlight went
dark, those house-hunting owls had already
fled.
NOVEMBER/DECEMBER 2024 53
http://www.leighannhenion.com/books
Blue Ridge Country Nov/Dec 2024

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