September 16, 2012
Millions Of Canadian Birds Killed Each Year From Window Crashes
April Flowers for redOrbit.com - Your Universe Online
A new study finds that feeding the birds might not be so nice, after all.Many Canadian homeowners have heard the thud of a bird hitting a window, but until now, little research has been done to document the significance of these collisions for Canada's bird population.
A University of Alberta biology class project supervised by researcher Erin Bayne suggests as many as 22 million birds meet their end in run-ins with Canadian homes.
Edmonton area homeowners were invited to become citizen scientists for the study, and evidence was gathered from 1,700 homeowners. The citizen scientists were required to fill out an online survey, asking them to recall fatal bird hits over the past year.
Bayne's team processed the Edmonton data and concluded that with approximately 300,000 homes in the study area, the death toll for birds from window strikes might reach as high as 180,000 a year. They applied that figure to national housing statistics to arrive at the 22 million figure for birds vs. window fatalities. The study, published in Wildlife Research, says that there is very little public awareness that residential window deaths might impact bird populations.
The age of trees in the yard and whether or not homeowners feed the birds seem to be the major deciding factors in the frequency of the window collisions.
"In many cases people who go out of their way to help birds by putting up feeders and bird friendly plants are unwittingly contributing to the problem," said Bayne.
One tip the researchers have for the safer placement of a bird feeder concerns its distance from the house. Bayne says the safety factor has to do with a bird's flying speed. As with car crashes; speed kills.
"A feeder three to four meters from a window is bad because the bird has space to pick up lots of speed as it leaves the feeder," said Bayne.
Fast-flying birds like sparrows and chickadees and aggressive birds like robins are apt to collide with windows placed too close to free food. Placing the feeder either closer to or much further from the house are better options.
The team believes many window collisions are caused by in-flight mistakes.
"It's called a panic flight; a bird startled by a cat or competing with other birds at the feeder may suddenly take flight and doesn't recognize the window as a hazard" said Bayne.