Editor:
Canmore is facing some great challenges with growth. Here, I wish to focus on wildlife corridors and sustainability. Wildlife corridors need sufficient connectivity and breadth. However, corridors are more than two-dimensional features across the landscape. There’s a vast third dimension in Canmore.
A deep and wide feature, the Bow Valley represents an important short and long distance bird migration corridor. The annual eagle migration takes advantage of Fairholme Range slopes, consistent winds and daytime heating that builds updrafts. But there are many other species here; eBird, an online checklist, records over 160 species in Canmore. Less obvious ones are nocturnally-migrating songbirds that use the valley as their route, choosing to migrate at night for cooler temperatures, denser air, less turbulence, avoiding main hawk and crow predators, and some use star patterns for navigation.
Nighttime lighting makes nocturnal migration difficult for birds. Poorly shielded or aimed luminaires spray light into the environment, create glare at ground level, and brighten skies, removing visual cues for birds. A 2022 CBC story about Canmore light pillars on a frosty night noted they are a sign of waste light emitted above the horizontal. Nocturnal bird migrants are attracted to light, get disoriented and are lured into colliding with lit windows. A 2019 Outlook article examined the negative role that light at night, particularly blue light at night, can have on human and animal health.
One reason people install nighttime lighting doesn’t stand up under close examination: studies show light at night is often related to increases in nighttime crime rates and may really only create a false sense of security for property owners.
Illumination at light needs more nuance, and less brute force. Use the right amount of light, aimed where it is needed with the correct spectrum to improve public safety, health, protect the natural environment and reduce costs and greenhouse gas emissions.
Last year, the mayors of Canmore, Banff and Calgary discussed building for sustainability, including reducing greenhouse gas emissions from the heating of buildings. Though not as large of a source of such emissions, nighttime lighting is easier to address.
Nature Canada’s Bird Friendly Cities program includes reducing light pollution. The Royal Astronomical Society of Canada will soon add Dark Sky Community” to their dark sky sites program. With forward thinking, Canmore could be one of the first communities so recognized, a status befitting Canmore’s natural splendour.
Roland Dechesne,
Carseland
Member of the Royal Astronomical Society of Canada’s light pollution abatement committee
