HIGHLAND PARK, Ill. - Etched window glass looks like a blank wall to birds, but humans see through it just fine
The City of Highland Park, joining other cities who want to be bird friendly, is considering whether to require design features that deter bird collisions in all new commercial, industrial and multi-family residential buildings.
According to the American Bird Conservancy, birds are unable to perceive glass as a barrier, and are easily confused by window reflections of the sky or trees.
"Most birds' first encounter with glass is fatal when they collide with it at full speed," noted the conservancy in its 2015 publication, Bird Friendly Building Design.
Estimates of the number of birds killed annually in glass collisions ranges from 100 million to a billion, according to the organization.
Under the Highland Park proposal, now before the city's plan and design commission, new buildings would need to satisfy the "bird collision deterrence" standards in a pilot credit program from the Green Building Council's Leadership in Energy and Environmental Design, or LEED.
The new program awards credits for bird-friendliness, taking into account materials, design choices and lighting management practices, as well as a building's proximity to trees, shrubs and bodies of water attractive to bird populations. Buildings are assigned scores based on multiple threats, and the whole building must have a "threat factor" of 15 or less to meet LEED guidelines.
Bird-friendly lighting practices include shutting off lights from midnight to dawn during periods of bird migrations - from March 15 to May 31 and from Aug. 15 to Oct. 31.
Among the favored design choices is the use of etched window glass, which the Park District of Highland Park used on its new interpretative center at Rosewood Beach.
"It looks like a blank wall to birds, but humans see through it just fine," said Donnie Dann, a local bird conservationist, of the bird-friendly glass at Rosewood.
In 2011, the Highland Park City Council added language to its building code requiring bird-friendly design and materials to the extent practical in new city buildings, something that came at Dann's urging. In June, the city's natural resources commission recommended bird-friendly requirements be extended to new commercial, industrial and multi-family residential buildings. The city council referred the matter to the plan and design commission.
The commission also is reviewing code changes aimed at reducing artificial light pollution, which obscures stars. That proposal would divide the city into lighting zones and set limits on spillover lighting in each district. The city would use the Illuminating Engineering Society's "BUG" rating system measuring backlight, uplight and glare.
"I'm sure we are going to end up being ahead of the curve (with both proposals), but at the same time, we don't want to turn anyone (developing property) away," said Commissoner Adam Glazer, who said he worried proposals would add to the cost of development in Highland Park.
Dann said the Congressional Budget Office found bird-friendly design materials and features to be cost-neutral when examining the Federal Bird-Safe Buildings Act, which was reintroduced this year by U.S. Rep. Mike Quigley (D-Chicago).
The bill would require that public buildings built, acquired or significantly altered by the General Services Administration must incorporate bird-safe building materials and design features as much as it can.