Reducing bird collisions with windows.
Reducing Bird Collisions with Windows
Portland is situated along the Pacific Flyway, a broad migration front that brings more than 200 species of both migrant and resident birds into our airspace. Though many of them are likely to stick to the forested uplands that flank the Willamette Valley, others are drawn into our urban landscape where they face a man-made hazard that is everywhere in the built environment: window glass.
It is estimated that up to a billion birds die annually as a result of window strikes in the U.S. alone, a mortality rate second only to habitat destruction. At our Wildlife Care Center we see between 200 to 300 window strike-related cases each year, or roughly 10 percent of the total case load. Birds do not recognize glass as a solid object and are prone to collisions, especially when passing through unfamiliar landscapes.
Portland Audubon is working to understand and reduce the risk to birds from window strikes in the Portland-Vancouver Metropolitan Region.
Bird-strike Surveys: Assessing the Problem
In order to get a better sense of the magnitude of this problem, Portland Audubon surveyed for birds that had been injured or killed in collisions with downtown Portland buildings from 2009-2012. This effort was funded by an Oregon Zoo Future for Wildlife grant and a Together Green grant from Toyota and National Audubon Society. We logged 36 species of native birds from our surveyed buildings. See Appendix 1 in the “Resource Guide for Bird-friendly Building Design” for a summary of our bird-strike study findings. Survey results helped us design current Portland Audubon programs that address the problem of window strikes.
Most songbirds migrate at night and rely on the moon and stars to navigate. Light emanating from cities drowns out these natural cues and can attract birds into cities, where they face deadly and deceptive building glass. Lights Out Portland is an effort to engage building owners in voluntarily turning off unnecessary overnight lighting during spring and fall migration seasons to minimize bird strikes and fatalities. Portland Audubon is actively working with individual building owners, city government, and agencies to adopt the LO program throughout the city. Learn more.
Portland Audubon collaborated with the City of Portland, U.S. Fish and Wildlife Service, American Bird Conservancy and local architecture firms to produce a Resource Guide for Bird-friendly Building Design in 2012. This 68-page booklet provides the most up-to-date information on how to build “bird friendly” buildings for new construction, redevelopment, or retrofits. On Oct. 2, 2013, the Portland City Council adopted a Resolution "encouraging the exploration and use of bird friendly design and practices in city plans and policies." Learn more.
The majority of bird strikes occur at residential homes. There are steps that each of us can take to make a difference: Find out what you can do to reduce strikes at your house. You can also sign up for the Audubon-Columbia Land Trust Backyard Habitat Certification Program and have a certification technician provide expert advice at your house.
Window strikes in Portland, video by Portland State University: