Every year, hundreds of millions of birds die following collisions with human structures. Glass windows, buildings, communication towers, and wind turbines are common bird-killers. A shining glass-faced skyscraper looks impressive to humans, but is invisible to birds, which are liable to fly full-speed into glass surfaces. Of U.S. bird species, about a third—258—are known to suffer window collisions. Collisions kill strong and weak birds alike. Overall, collisions are estimated to cause the death of one billion birds each year in the U.S.
Some U.S. cities, jurisdictions, and one state are protecting bird populations with legislation. Bird-friendly building design requirements have been adopted in San Francisco, Oakland, several Illinois counties, and Minnesota. Here in Portland, political leaders have been prioritizing bird health since 2003, when Vera Katz and City Commissioners entered into the Urban Conservation Treaty for Migratory Birds, an agreement with the U.S. Fish and Wildlife Service (USFWS). In 2011, the City of Portland received a challenge grant from USFWS to create voluntary Bird-friendly Building Guidelines for local construction. Two years ago, the City formally adopted the Portland Bird Agenda, which outlines how the city will prevent bird collision deaths.
More than 200 species of birds may be found in Portland, due to the city’s location along the Pacific Flyway, a migration highway between Alaska and Patagonia. Portlanders love birds—consider how we flock to northwest Portland to see swifts roosting in Chapman Elementary School’s chimney. Hundreds of Portlanders take part in the Backyard Habitat Certification Program. Many of us also enjoy watching a wide range of species from our own porches. From pollination to pest control to seed dispersal to tourism, birds bring multiple benefits to the Rose City.
The Portland Bird Agenda outlines the City’s bird habitat protection and improvement efforts, policies for reducing bird hazards, invasive species management, and education/outreach programs. The City of Portland includes bird-friendly building methods in its Green Building Policy. Contractors can also receive LEED credit for bird-friendly building methods.
As Portland building demolition contractors, we are happy to see the construction of more and more bird-friendly buildings. To prevent collisions, designers can use multiple approaches.
• Pay attention to the lower 40’ of a structure; this is where most bird collisions occur.
• Opt for tinted, opaque, or translucent glass.
• Avoid problematic glass placement—such as windows at corners, glass adjacent to a rooftop garden, and freestanding glass around courtyards.
• Treat windows in high-risk zones, via window films, etching, tinting, or exterior shades.
• Enclose glass facades within netting or screens.
• Use landscaping, awnings, louvers, overhangs, and deeply recessed windows to minimize collisions.
Additionally, bird-friendly buildings should shield outdoor lighting. Most songbirds migrate at night, and light can confuse them.
While providing demolition in Oregon, we attempt to recycle as much as possible from a building site, and we appreciate building designers that seek to use recyclable materials in their designs. As Oregon demolition pros, we love how glass can be endlessly recycled. Glass is one of the most reusable building materials. Yet its placement must be tempered with an awareness of how birds could be impacted.