Bird-friendly glass at The Audubon Discovery Center in Philadelphia, Pennsylvania.

Photo credit: Luke Franke.

Bustling Austin is growing not only out but up, and that poses a deadly threat to birds — not just our native species but those migrating through here.

Window collisions are one of the chief causes of bird fatalities across the country.

Buildings with highly reflective glass windows and doors can be lethal because the glass acts as a mirror, reflecting trees or blue sky. Birds that mistakenly fly into these windows often die. Even those that are able to fly off may have head trauma or a broken beak, which prevents eating or drinking. Young birds who are inexperienced fliers are particularly vulnerable.

Victims of window collisions. Courtesy of Madison Audubon.

Austin’s building boom is drawing concern for the number of structures with highly reflective glass. Some projects are planned near major waterways or green belts where bird traffic is high.

Travis Audubon is actively reaching out to developers and suggesting ways to mitigate bird collisions. City planners and commercial builders need to remember that Austin is fortunate to be located in the Central Flyway — an aerial “superhighway” that birds use during their spring migration from south of the border to their northern breeding grounds. As cooler fall weather sets in, these migrants retrace their route on the flyway, returning to habitats as far south as Argentina.

“Austin’s location on the Central Flyway is why we see such a huge variety of birds in the spring and fall as many migrating species stop here to rest and bulk up before resuming their journey,” says Chris Gunter, president of the Travis Audubon board of directors. “Birds tend to stay close to waterways, such as the Colorado River, and wooded areas. That’s why placing highly reflective glass buildings in their path is a recipe for disaster.”

One important deterrent is to incorporate bird-friendly design in new buildings. Travis Audubon is consulting with Endeavor Real Estate Group on redevelopment plans for the former Austin American-Statesman site at Riverside and Congress. The 19-acre property, which sits on the banks of Lady Bird Lake, is slated to contain multiple high-rise buildings as well as green space.

Endeavor representatives have been receptive to strategies such as reducing the degree of glass reflectivity, Gunter said. Discussions with the developer and their architects produced an agreement to use glass throughout the project with a lower exterior reflection than what was originally proposed. Now the entire project will use glass with no more than 20 percent reflectivity, Gunter said.

Travis Audubon has been invited to suggest other bird-friendly design features for the redevelopment, which is moving forward with the Austin City Council’s approval.

Another building project in the sights of Travis Audubon is a major mixed-use redevelopment proposed in East Austin at the home of the Borden Dairy. The 21-acre site at East Cesar Chavez and U.S. 183 is adjacent to the Colorado River Park Wildlife Sanctuary which sits next to the Colorado River. The project, also represented by Endeavor, would feature buildings up to 120 feet tall, if existing plans are approved by the city council.

Gunter said Endeavor has also expressed a desire to work with Travis Audubon on this project to identify bird-friendly design features that might be incorporated.

Meanwhile, bird-safe design features can garner points toward earning a LEED designation for sustainable commercial buildings, as determined by the U.S. Green Building Council. Many cities including Portland, Philadelphia, San Francisco, New York, and Toronto already have embraced bird-safe guidelines.

The American Bird Conservancy has issued a comprehensive manual, “Bird-Friendly Building Design,” which offers recommendations for not only bird-safe windows but other design features that could reduce bird mortality.

How to make yards and homes safer for birds

Tall buildings aren’t the only threat to birds in flight, so are glass windows and doors in houses and apartment complexes. National Audubon offers these suggestions to avert crashes:

1. Paradoxical as it may feel, try placing your bird feeders close (1.5 feet or less) to your windows. This will make birds slow down as they approach.
2. Apply a thin film to the outside of windows (www.collidescape.org). The glass will become visible to birds but remain transparent for you. As a bonus, the film will cut down on incoming infrared radiation so it lowers summer cooling costs.
3. Keep curtains or shades drawn during the day to reduce reflection.
4. Place window decals, sun catchers, tape strips, ribbons, or anything of your choosing in a dense pattern in the “2×4” format (multiple markings 2 to 4 inches apart are recommended). A single decal will not work. Even painting windows with tempera paint, chalk markers, or marking them with soap will prevent collisions.
5. Move indoor houseplants back from windows as they may attract birds.
6. Install a screen or net a few inches outside of windows to lessen the impact.