Alarming rise in bird-window collisions in downtown Calgary: wildlife experts
Surveyors who monitor downtown Calgary to record the number of downed birds that have collided with windows are reporting a significant increase in their findings.
The Calgary Urban Species Response Team monitors the city's downtown during bird migration seasons each year to record how many they find either injured or dead after striking a window.
Since the beginning of August, the team has found 91 birds that have hit downtown windows, a steep rise from their numbers last year.
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"We're already at almost 100 animals that we've found at the downtown buildings that we regularly survey, so that's pretty extraordinary," said Sara Jordan-McLachlan, the team's program manager. "We had 11 at the same time last year."
The work for Jordan-McLachlan's team every spring and fall is to get a better idea of how common this issue is in Calgary, as well as to rescue as many injured animals as possible.
Jordan-McLachlan noted that just one per cent of bird-window collisions occur at high-rise buildings. The vast majority happen at smaller buildings or houses instead, where bird activity is more common.
She argued that means the rise in collisions her team is recording indicates a far bigger problem exists around the city, which should concern humans given the importance birds carry in our environment.
"These birds are a part of our ecosystem," Jordan-McLachlan said. "They're an important indicator of environmental health, they're important for controlling insect populations, for nutrient cycling, seed dispersal."
Most of the birds the team has picked up have been chipping sparrows, Jordan-McLachlan said. They've also found red-breasted nuthatches, a northern waterthrush, and a couple species of warblers.
The team sends the dead birds they find to the Royal Alberta Museum in Edmonton for further study. Any injured animals they come across are scooped up in nets and transported to the Calgary Wildlife Rehabilitation Society.
Cutting the lights
While more research is needed to find what's causing what Nature Calgary president Kaya Konopnicki calls a "pretty dramatic" increase in the findings, she said artificial light illuminating indoor plants that birds may view as shelter is one major factor.
Because glass isn't a natural material, Environment Canada warns that some indoor plants, as well as reflections of trees and plants in windows, can confuse birds. This is especially true for younger animals that aren't used to flying in urban areas.
As a result, Environment Canada noted window collisions can kill between 16 and 42 million birds per year across the country.
Artificial light can also disorient birds migrating at night that use the moon and stars as guidance, Environment Canada added.
"We've changed the night sky so much and the night landscape, and birds fly toward the light. So that's one really big thing," Konopnicki said.
"That reflection of trees and other things in the windows [also] really confuses birds."
Both Jordan-McLachlan and Konopnicki advised that small changes like turning lights off at night or putting stickers in windows can make a big difference to reduce bird deaths, especially from August to October during fall migration.
"This is something that's so easy to mitigate," Jordan-McLachlan said. "We know that if we just mark windows and we turn off lights at night, that's going to make a huge difference."
This article, written by Andrew Jeffrey, was originally published for CBC News. Header image courtesy of Getty Images