Dear Architects: Please Stop Designing Glass Buildings that Kill Birds

I love birds. Not a day goes by that I don’t see a bird and appreciate its color or song or just the plucky way it goes about its daily activities. Full disclosure: I’m an ornithologist, so I’m expected (and, in fact, paid) to think about, appreciate and protect birds, but they make it easy for me; they’re pretty remarkable.

For many of us, birds are the only wildlife we see regularly, besides perhaps the occasional squirrel. I think that this proximity and presence forges a bond between humans and birds and imagine that most of us — ornithologist or not — appreciate the beauty that birds bring to our lives. Birds also do amazing things, perhaps the most notable being migration. Some migratory species, like raptors and cranes, are large and powerful — but many can fit in the palm of your hand.

Buildings like the US Bank Stadium in Minneapolis have been reported as being perilous for birds that collide with highly reflective surfaces; via Wikipedia

A Ruby-throated Hummingbird weighs in at just over 1/10th of an ounce, yet they fly between Central America and eastern North America where they breed, twice a year every year! That journey includes a non-stop flight across the Gulf of Mexico — a feat that can take up to 22 hours. Think about that for a minute. That’s incredible for any bird, much less one that weighs little more than a penny.

“Hundreds of millions of birds are killed in the United States every year after crashing into glass.”

Massive water bodies like gulfs and oceans are not the only barrier that birds face on their migratory journeys; they have to contend with many barriers created by humans as well. One of the most ubiquitous of those is glass. Hundreds of millions of birds are killed in the United States every year after crashing into glass as they attempt to navigate our built environment. Those Ruby-throated Hummingbirds that fly across the Gulf of Mexico? Research shows that they are among the species most at risk of collision.

At one point in my career, I worked at a zoo. Whenever we introduced a new bird into a glass-fronted exhibit, we would put an opaque glass polish on the outside of the glass for the first few days. This process allowed the bird to learn to see the wall of glass as a barrier and, when we removed the polish, they would remember and treat that barrier appropriately.

The owners of Consilium Place Towers were sued by environmentalist groups that accused them of failing to protect hundreds of birds that died crashing into their buildings. The environmentalist groups were defeated in court — but the building owners applied film to the glass to mitigate the problem nonetheless. Image via The Star

That knowledge and experience is something that migratory birds don’t have. When they arrive in a new location and need to fuel up quickly, glass often proves deadly. They don’t see the glass or a barrier at all — what they see is the habitat or sky reflected in it or visible through the glass on the other side, and that has deadly consequences. With all the challenges that birds face, wouldn’t it be great if we could help them negotiate our human-dominated landscape a bit more easily?

“Small songbirds need numerous, closely spaced markings so they choose to turn away rather than try to fly through.”

Thankfully, there are ways we can help them that don’t involve everyone slathering their windows in glass polish. As we’ve learned more about birds’ perceptual abilities we’ve been able to develop ways to make glass more apparent to birds — and those hawk silhouette stickers stuck in the middle of big glass panels, sadly, are not one of those ways. Birds are really good at navigating through tight spaces. So, while patterns on glass do indeed work, small songbirds need numerous, closely spaced markings, hawk shaped or not, to close up the gaps so they choose to turn away rather than try to fly through.

Glass products that birds can see and avoid are already available, often designed for other purposes. Additionally, some glass manufacturers have taken birds to heart and developed product lines to help. Some of these pioneering companies have products on Architizer. For example, Walker Glass produces Aviprotek – a glass with acid-etched patterns on the #1 surface where they are most effective and specifically designed to show birds that there’s a solid barrier present, without compromising aesthetics.

AviProtek is a bird friendly solution by Walker Textures with acid-etched designs on the surface of the glass.

Another company, Viracon, produces a number of fritted glass products that have dotted or striped patterns which appear visible to birds and seem to warn them away from the surface. There are additional companies that produce bird-safe glass that currently are not available on Architizer, including Ornilux and Glaspro Birdsafe glass. Besides surface markings like etching and fritting, there are countless examples of beautiful architecture that incorporates other screening or shading methods that serve other key goals and can also steer birds away from glass.

“Bird-friendly design can earn you points towards LEED certification.”

Incorporating bird-friendly design can be an interesting and exciting contribution to the overall sustainability goals of a project, and should not increase project costs if considered deliberately from the beginning of the design process. At that stage the options are as vast as the creativity of your team. And consider this — bird-friendly design can earn you points towards LEED certification through the popular Pilot Credit for Bird Collision Deterrence.

So I’ve made it my life’s work to conserve birds, while encouraging more people to appreciate, enjoy and care about birds enough to help protect them and the places they need to thrive. You can help. Put birds in your plans from the start; build bird-friendly!