Join the dark (sky) side

No cookies (yet), but birds & stars.   

Quality of night sky across settlements. Credit: Sriram Murali

The night sky is woven with stories of past, present and future. Centuries of weary navigators relying on the ever-bright Polaris to guide them home. Folklore, passing along generational wisdom. And little children connecting dots to see kings of the past. But a few too many streetlights conceal this beauty for so many of us now.

Artificial light pollution is excess light from urban cities – streetlights, billboards, garden decorations – creeping into the darkness above. Light pollution might fly under your radar, but it has impacts on navigators, storytellers and young ones of human and avian origin.

If you’ve ever walked along the Scores, hoping to look up at the endless wonder of glittering gas-balls, only to be blinded by a streetlamp shining directly in your eye - then you’re already aware of one of the problems of light pollution. Glare.

DANGERS OF GLARE

Street lights are installed globally to increase visibility, prevent car accidents and discourage crime in the depths of night. Yet, glare from excessive lighting can increase all these.

Our pupils help us see in the dark, growing in size to seek out spots of light in the vast darkness. Thanks to dilated pupils, we can see people in the dark and stars in search for light. In bright light, our pupils shrink to constrict the amount of light that can enter our eyes in the now bright environment. When our eyes flit between a bright light and a dark environment, seeking out light is much harder because of our constricted pupils. This lowers the contrast of our surrounding and has a blinding effect that decreases visibility.

This makes it harder for drivers to see pedestrians and can conceal perpetrators in plain sight. Instead, adding hoods or shields onto low-level lights can target light downwards onto roads without blinding drivers or pedestrians.   

Effect of hoods on night sky visibility. Credit: Astronomy - Roen Kelly

Hoods don’t just solve these issues, but another problem that extends far beyond human experience. I entered this dark sky space from a love of the stars, but over the past semester, I’ve been sneaking around in birder-territory and learning about another shocking side of the light pollution story.

HAVOC ON BIRDS

Undirected light from streetlights travels up into the night sky, although there are no pedestrians or drivers up there. “Skyglow” is the suspended light from urban lighting that spills into the airspace. This wasted light is not a just neutral side effect to lighting up our streets, but costly wreaks havoc on bird behaviour, migration and survival.

Urban lights ruin the night and day cycles that guide the internal rhythm of bird behaviour and sleep (and for humans too, but that’s for another blog). The blurred transition between light and dark leaves birds active and awake for longer than they should be, causing exhaustion and out-of-sync behaviours.

St Andrews is home to several seabird species, who make their homes with young fledglings in around our beautiful shores. But these birds, especially their young, are fatally affected by artificial light.  Lights cause disorientation and the birds are forced to land – often causing collisions with urban infrastructure. Once grounded, they struggle to take off again, leaving our seabirds vulnerable to starvation and predation.

And visitors to our town feel this as well. Migratory birds travel many miles for their perfect habitat, facing unpredictable challenges and conditions on their way to or from breeding grounds. But one challenge is man-made… you guessed it, artificial light pollution. This hits migrating birds especially hard, where they are diverted from their route and attracted to lights and cities that they collide into.

Cory’s shearwater grounded by artificial lights. Credit: DarkSky - Airam Rodriguez

Before they set off, migratory birds use daylight length as crucial indicators of the seasons and when they should be heading to their summer or winter homes. But lights that run all year round at the same times mess with this rhythm, and mistiming migration can be fatal for many birds. If a bird arrives too early or late in the season, they miss the window of abundant food, resources and favourable climate that they have travelled so far to get. It’s the difference between a warm summer filled with offspring, or starving to death in a cold gust of spring.

St Andrews is lucky to be a coastal town, full of wildlife and diversity, but the wildlife around us is unlucky to be so close to the pollution we create.

RETURN OF THE NIGHT

So, safety, stars, ssssad birds. Glare has got to go. How? The DarkSky initiative is a great place to start - they advocate for better lighting and better nights, providing a community and help for anyone looking to get involved.

The solution is not to remove lights altogether. Instead, there are three key practical, energy-saving and night-protecting solutions:

1. Warm toned lights.

Bright, blue lights scatter in the sky more than warmer, orange light – causing glare and blinding effects. Swapping lightbulbs to warm tones improves vision, is more comfortable and feels safer.

2. Shielded lamps.

Guiding light downwards focuses the light onto the streets, where we want it, and not into the sky. This is a simple addition that has a big effect, and a great place to get started in the DarkSky movement.

Before and after shielding LED lighting in Dunedin, New Zealand. Credit: Brad Phipps

3. Switching off unused lights.

The easiest and most effective way to reduce light pollution. Turn off all the office lights when you leave! Does your garden really need to be lit up 24/7? Is there a display in a shop window that does not need to be on at 2am? Many towns adopt a light pollution curfew, where unnecessary lights are switched off between 10pm and 6am.

These strategies can restore our night skies. Start in your own home, in your community and within your local council to bring back the wonder of the night and protect the nature living in it.

Join the dark sky side.