Why – and how – to rewild the night

As the sun sets, a badger wakes up from its daytime slumber and crawls out of its burrow in a remote corner of a city park. Driven by hunger, it sets off for a night of foraging. Traditionally, the darkness has been a shield keeping the small, slow-moving animal hidden from predators such as coyotes or owls that are also on the prowl for food. But in this urban setting, the glare of lighting from streetlights, cars and buildings has placed the park in a perpetual twilight, illuminating the badger and making it vulnerable.  

Approximately 70 percent of mammals are nocturnal but, like the badger, can no longer depend on the darkness of night to survive. As humans have increasingly encroached upon their territory, artificial light at night has followed. According to astronomer Dr. Rosanna Tilbrook of Vancouver’s H.R. MacMillan Space Centre, 80 percent of people on this planet live under a light-polluted sky. This has created conflict for wildlife, who have become 1.36 times more active at night in attempts to avoid humans.

This too has consequences. According to Jackie McQuillan, programs director for the Wildlife Rescue Association of B.C., a large number of wildlife rescues happen in the morning, which leads to the belief that something went awry in the night.

“By giving [animals] back the dark night, they could find what they need more efficiently, the conflict would be mitigated, and natural behaviours would become permissible,” says McQuillan.

Wildlife at risk

The issue, though, isn’t just limited to nocturnal mammals, like the badger – it’s widespread across many species. “There is plenty of research,” says McQuillan, “that shows bright night light can really change the migration patterns of birds.”

Most migratory birds fly at night. They keep on course by using the stars and moon. When office towers leave their lights on, the birds confuse the light for a navigational beacon and, instead of veering away from it, fly directly into it. According to McQuillan, 42 million birds are killed by window collisions in Canada every year.

The story is different, however, when the lights are turned off. Since 1995, Chicago’s Lights Out initiative has encouraged buildings 40 stories or higher to turn off the lights or draw their blinds after 11 p.m. during spring and fall bird migrations. The result is that the lives of 10,000 birds are saved each year.

Even nocturnal pollinators such as moths – who account for a third of all pollination in urban areas – are affected by artificial light. One 2016 study found that streetlights reduced moth abundance at ground level by 50 percent, which in turn decreases overall pollen transport in lit zones.

But despite these dire consequences, the world continues to get brighter, especially in urban areas. From 2011 to 2022, citizen scientists working with the nonprofit organization Globe at Night recorded a 7 to 10 percent annual increase in nighttime sky brightening.

Preserving the darkness

There is, however, a flicker of hope as organizations work to combat the problem. For example, the Royal Astronomical Society of Canada (RASC) and partners including Parks Canada, cities, municipalities and conservation groups have designated 32 sites across Canada as Dark-Sky Sites. They fall into three categories. Dark-Sky Preserves are typically found in remote corners of national or provincial parks where little to no artificial light occurs. Urban Star Parks, because of their topography, have some light present but are still suitable for astronomy. And then there are Nocturnal Preserves.

“In the case of nocturnal preserves,” says Bob King, national chair of the RASC light abatement committee, “we allow brighter skies, and we don’t require it be a site for astronomy but that it must really focus on preserving the nocturnal environment for the animals and birds that frequent the area.” Canada has three nocturnal preserves, including the Ann and Sandy Cross Conservation Area near Calgary, Alberta.

Access to the area is prohibited after 11 p.m. to allow wildlife to roam undisturbed. However, even this measure is not enough, especially in the northeast corner closest to Calgary, where the glare from the city extends deep into the reserve. This phenomenon, known as skyglow, is caused by office towers, malls, industrial parts, streetlights and even backyard porch lights that remain lit overnight. The light refracts off water molecules, dust particles and pollution in the lower atmosphere to create a vast expansive dome of diffused light that hangs over urban and suburban areas.

4 steps to darker skies

“The onus is on everyone,” Tilbrook says, to help preserve the night sky. No matter whether you work or live in a city high-rise or have a suburban backyard there is something you can do.  

Assess your outdoor lighting

If a light is not needed for safety, such as illuminating stairs or walkways, remove it or install timers so that when you are asleep, so are the lights. The lighting you do need should point downward to avoid sending glare towards the sky. The widespread rise of energy-efficient LED lights has made the cost of keeping the lights on cheaper, but also the night brighter. King suggests choosing (or setting) LED or incandescent lightbulbs on the warm side (below 3000 Kelvin), especially if you are in an ecologically sensitive area.

Create a safe nocturnal environment

Native plants specific to your region provide accessible food for nighttime foragers. Plant them in clusters in your backyard to create microhabitats where small animals can hide if needed. 

Keep pets indoors after dark. A nocturnal mouse is a great snack for a cat. Minimize noise by removing noise makers such as wind chimes. By echoing the silence of the forest, we help foraging wildlife feel safe.

Be a dark sky advocate

Foothills County, Alberta, where the Ann and Sandy Cross Conservation Area is located, requires shielded streetlights to reduce glare. If your community lacks similar by-laws, contact local representatives and explain why dark skies matter. Office buildings leave their lights on at night for security reasons and cleaning staff. If you work in a building that does this, get a group together and suggest to the building maintenance that the lights be put on timers.

Talk about the need for darker night skies with family and friends and post online to raise further awareness. 

Visit a dark sky preserve

For more than 20 years, DarkSky International has advocated for reduced outdoor lighting to protect ecosystems, wildlife, plants and astronomy. Check out the resources they offer online including a list of Dark Sky Places around the world. Plan a visit to one near you to see firsthand a true night sky.

“You’d be able to see the Milky Way stretching all across the night sky,” says Tilbrook. “You’d be able to see thousands of stars, astronomical phenomena like comets and northern lights. A completely dark sky is like nothing you’ve ever seen.”