Bird conservators have long campaigned against feral cats and rampant windmill development, due to their links to bird deaths. Add large, reflective structural windows to that list, of course. Many people have seen the sad, ghostly imprint of a bird that met its end with a pane of glass.
In fact, buildings, along with bridges and other manmade structures, are responsible for an estimated 1 billion birds deaths each year, and glass is the specific cause in most cases. In an effort to stem that toll on wildlife -- many of the birds that die each year are in the midst of important migration routes -- the U.S. Green Building Council is rolling out "bird collision deterrance" as a building strategy that is eligible for points under the Leadership in Environment and Energy Design (LEED) green building rating system.
Birds tend to perceive reflections in large glass panes as continuous space. Or they see trees or other natural objects reflected in the glass and they fly toward those objects with gusto. Making structural glass safer for birds entails working patterns or other "visual noise," into the exterior, such that birds are encouraged to steer clear of the structure. Making modifications to glass reflectivity, color (including ultraviolet reflectivity) texture, or its opacity are other strategies.
The LEED credits are being tested as part of the LEED Pilot Credit Library, which is a process through which the LEED credit system evolves to ensure that its rating system is fair and effective. Through the pilot program, new building technologies and concepts are put to real-world tests and then evaluated. If the pilot testing shows the tools or technologies to be effective in lessening a building's environmental impact, they could be codified into the LEED system of building credit or prerequisite. If not, the credit may be reduced or removed from the LEED library altogether.
Some architects and designers have already started integrating bird safety into buildings, and bird safety is addressed in the environmental impact statement for the reconstruction of the World Trade Center in Manhattan. Some cities, including Toronto, Chicago, and most recently San Francisco have added bird safety measures into their green building requirements. And Minnesota is working bird safety into its statewide Sustainable Building Guidelines.
Designers are also experimenting with technologies that would produce glass that is visible to birds but not humans, says Christine Sheppard, the director of the American Bird Conservancy's Bird Collisions Program.
But it's not just skyscrapers that threaten avian populations. The large windows that attract buyers to new homes also attract birds, as noted in this Star Tribute article. A couple who purchased a home in Victoria, a bucolic suburb of Minneapolis, found that putting screens over their largest windows cut down on the bird fatalities they were witnessing regularly at their heavily-glazed home.
This post was originally published on Smartplanet.com