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Metal Architecture and Bird Conservation?

Metal architecture plays an important role in preventing collisions

Abc Guest Jacob Javits Center Christine Sheppard
Jacob K. Javits Convention Center in New York City. {Photo: Christine Sheppard}
Architects, owners and contractors have long been aware that non-native House Sparrows, English Starlings and, of course, Rock Pigeons excel in roosting and nesting where they are not wanted and generally design accordingly. In the Constructive Insights column in the June 2017 issue, Alan Scott, FAIA, described the huge toll, hundreds of millions of songbirds, taken every year in the U.S., by collisions with glass on buildings.

Increasing awareness about the staggering impact of glass buildings on birds demands that new strategies and tools be employed to create safer structures. Metal architecture has many benefits, but you might not know that this can include contributing to the conservation of native bird species. Metal architecture can continue to play an important role in shaping more attractive and healthier interfaces between our natural and built environments and save birds, too.

People think we can see clear glass—but we really can’t. As infants, we learn the concept ‘glass=invisible barrier’ as we bump (usually gently) into doors and windows. As we grow, humans learn architectural cues that tell us where to expect glass, including frames and floor material changes, or by surface dirt, distortions, tones or integrated patterns.

Even then, humans are still capable of walking into glass—but it is much worse for birds. Birds are probably incapable of learning about glass as a concept, and while some resident birds can learn about specific pieces of glass, the most frequently killed birds are visiting migrants, flying north to breed in spring and south for the winter. Along the way, migrants land in unfamiliar places, often near buildings, searching for food to refuel—and are killed the first time they fly toward a tree or a shrub, either seen through a piece of glass, or, more typically, seen reflected in the glass. For the birds it makes no difference because they cannot distinguish between these two phenomena.

Williston_ABC Guest

Williston Area Recreation Center in Williston, N.D. {Photo courtesy of JLG Architects}

Naturally, this places a lot of attention on glass as the problem and patterned glass as part of the solution. Appropriate patterns on glass are interpreted by birds as obstacles with gaps too small to fly through, so the right patterns cause approaching birds to swerve away. This is one of the most important ways to create bird-friendly design. But there are other strategies that can help reduce collisions and they include using metal products. In fact, of the three main strategies useful for protecting birds, metal materials are important to one approach, and form the basis of a second. For fabricators and designers, reducing bird collisions is an added value that many companies can tout for their metal wares, especially when integrated with strategies for other improved performance outcomes.

Reducing use of glass where it is not needed is the first strategy. Multiple studies have confirmed that, in a given region, larger amounts of glass and larger panels of glass correlate with more bird deaths. The original Jacob K. Javits Convention Center in New York City, mentioned in Scott’s editorial, was known for high rates of collisions, based on monitoring by New York City Audubon. As part of a major renovation, bird-friendly glass was used, but the most dangerous glass, adjacent to a row of trees, was replaced with steel panels. Use of glass with low reflectivity makes the internal structure of the building visible much of the time, signaling to birds from a distance to avoid that flight path. For birds that continue to fly toward the building, a frit pattern in the glass becomes visible at closer range, an effective deterrent. Even though the renovated Javits Center is now larger, with more glass and includes a green roof, monitoring shows that total collisions have dropped significantly.

Increasing awareness about the staggering impact of glass buildings on birds demands that new strategies and tools be employed to create safer structures.

A second important collisions prevention strategy is using structures like screens, louvers, shutters and shades to cover the outside of glass. This overlaps with strategies for controlling heat, light and glare, as well as providing privacy, security and identity. Screens can wrap an entire building or be specific to a single window. Louvers can be fixed or operable, shades can be deployed as needed, whether to reduce insolation, protect birds during migration, or reduce likelihood of burglary.

The design of the Williston Area Recreation Center in Williston, N.D., designed by Grand Forks, N.D.-based JLG Architects, is a good example, including not just metal walls but screens. What is essential, is to consider and discuss bird impact early in design, identifying areas where views may not be essential (for how many conference room windows or building connectors are perfect views required?) and using bird-friendly elements to increase better qualitative outcomes overall.


Christine Sheppard, Ph.D., is the director, glass collisions program at the American Bird Conservancy, The Plains, Va. To learn more, visit abcbirds.org.