House Windows are a Threat to Birds
The sickening thud of a bird crashing into a window is an all-too-familiar sound for many Canadian homeowners. Birds often mistake windows for openings, flying into the glass at full speed. A startling new analysis suggests about 22 million Canadian birds die each year from such crashes, researchers reported Sept. 4 in Wildlife Research.
Undergraduate biology students at the University of Alberta, supervised by biologist Erin Bayne, surveyed 1,750 local residents in person and through social media. The recruited citizens provided the number of fatal bird strikes at their homes during the previous year. By extrapolating from these local reports, the researchers calculated the collision rates for different types of homes and then estimated the national bird mortality rate. The study did not include bird strikes on skyscrapers or commercial buildings.
"Most houses have had zero collisions in the last year, but others had many more," Bayne told mongabay.com. Rural houses with bird feeders and lots of vegetation generally had more bird fatalities—as many as 43 in a year.
Photo shows bird silhouette adhered to a window. Using stickers or objects to break up a window’s reflection can help prevent bird deaths. "Not surprisingly, when you have more birds present you have more collisions," Bayne said.
Common birds, like sparrows, robins and chickadees, accounted for most casualties. Bayne’s study found no endangered birds killed by windows, but he mentioned that for an endangered species, "even a few collisions could have a big impact."
Photo by: Sharat Ganapati via MONGABAY.
Read more at ENN Affiliate, MONGABAY.