by Erling Friis-Baastad
University of Alberta graduate student Justine Kummer would be grateful if you would wander around your yard – preferably many times – while keeping an eye out for dead or injured birds.
According to the website for the University of Alberta Birds and Windows Project, “it has been estimated up to 1 billion birds are killed in North America each year as a result of bird window collisions! This is one of the largest threats facing urban bird populations.”
Developed and run by Kummer and her colleagues out of the University of Alberta in Edmonton, the project provides an opportunity for non-scientists across North America to do something in response to that staggering fatality statistic.
“The Birds and Windows project is a continuation of one we did a few years ago,” Kummer says. “Participants were asked about the history of collisions with their homes. We learned a lot from the study, but we decided we could do a lot better.”
The initial undertaking became part of a significant, even pioneering, Environment Canada document. It revealed that window collisions ranked just behind cats when it comes to bird fatalities. However more accurate data than could be provided by homeowners’ memories was needed.
“We decided that we would design a study where homeowners walk around their houses for a certain period of time, then report to us – whether or not they found anything like a collision or not,” says Kummer.
She designed the study and constructed the website (http:/birdswindows.biology.ualberta.ca/), which was launched in September. It highlights the problems and gives participants guidance on what to look for:
“Evidence of bird window strikes includes dead or injured birds found beneath a window or blood smears, body smudges or feathers found on window glass….”
So far, about 800 people from across the continent have responded to the project, with more than 20,000 observations. Scientists are that much closer to understanding just how severely window collisions are affecting avian populations and to finding solutions.
Birds colliding with windows “is definitely a Yukon problem,” says Katie Aitken, an instructor and co-ordinator with the School of Science at Yukon College. In co-operation with the Canadian Wildlife Service the college maintains a collection of dead birds donated by the public. The corpses become a learning resource for students of biology and related fields. The collection contains about 500 birds, and most are probably victims of window collisions. The hard data is just beginning to come in, says Aitken.
Much money and effort is put into studying forest management, land use, seismic lines and oil and gas development, but the effects of window collisions and of predatory cats are generally underrepresented, she says.
Of the study collection of birds accumulating at the college, many were found beneath feeders in late winter. These include redpolls, grosbeaks, crossbills and, especially, Bohemian waxwings, she says.
Waxwings travel in flocks, often landing in ornamental trees near windows.
Meanwhile, spring migrants, such as robins and juncos, breed in urban areas where there are, obviously, many windows. Preoccupied with the stresses of finding food, mating and nesting, the birds may startle easily, panic and mistake a reflection in glass for a safe expanse of forest or shrubbery – “and ‘boom,’ into a window they go,” says Aitken. The largest bird in the sad collection, so far, is a grouse, she adds.
Skyscrapers account for many fatalities among the larger birds, such as hawks and falcons, says Kummer. However, people assume that office towers account for most bird fatalities, when residential housing actually accounts for 90 per cent, according to the Birds and Windows site.
So how is all the new information going to help reduce the staggering number of collisions each year?
The survey collects data on house design, yard characteristics, and distance of feeders from building, among other things. With such structural information products can be developed to steer birds away from hazards. Among such developments are ultraviolet window decals and tape that help break up reflected images and are more readily visible to birds than people.
The University of Alberta Birds and Windows Project will run at least through the end of 2014, says Kummer. Meanwhile, according to the Birds and Windows website, homeowners can help reduce bird collisions by employing some of the following strategies:
• Place bird attractants within one metre of windows. (Birds pick up less speed over shorter distances.)
• Uniformly cover the window surface with decals and hanging strings of objects.
• Keep interior blinds and shutters closed.
• Move houseplants away from windows.
• Angle windows 20-40 degrees downwards.
• Cover windows with netting.
• Use ceramic frit glass.
• Use one-way films that consist of chosen patterns and colour shades.
• Create a pattern on your windows using ABC BirdTape.
This column is co-ordinated by the Yukon Research Centre at Yukon College with major financial support from Environment Yukon and Yukon College. The articles are archived at http://www.yukoncollege.yk.ca/research/publications/newsletters–articles