Like in other cities, buildings in Philadelphia's Center City have reflective glass surfaces that fool birds so that birds die in window strikes. Two researchers that have been studying the problem estimate that about 1,000 birds die each year in their four-block study area on Market Street. Most of the victims are migratory songbirds such as Ovenbirds and White-throated Sparrows, but they also include American Woodcocks and Wild Turkeys. Possible solutions, like elsewhere, involve shutting lights off at night during periods of heavy migration and incorporating designs that make glass surfaces more visible to songbirds:
Films applied to the glass to make it visible are one idea. At Temple University, art students held a competition to come up with attractive and effective designs. The winning version resembled sheet music with the notes shaped like birds.
Another student cut translucent film into the shape of molecules for the chemistry building's windows.
A New York company, SurfaceCare, provided a film with small, almost imperceptible, black stripes for the Bear Country exhibit at the Philadelphia Zoo, which, like many other zoos, has a combination of glass enclosures and trees. The bird strikes stopped.
SurfaceCare owner Marc Sklar is looking at new technologies, including glass that has elements in the ultraviolet light spectrum, which humans can't see but birds can.
Christine Sheppard, a bird collision expert with the American Bird Conservancy, has been testing prototypes of bird-friendly glass at a bird-banding station near Pittsburgh. She said the results could be used to write guidelines for architects.
"Nobody wants to kill birds," she said. But, still, "nobody wants more rules and regulations." Her goal is to educate.
"There are lots of beautiful buildings that are very bird-friendly," she said. "You can be creative and do architecture that will win awards" and still not kill birds.
Recently, the national green building certification program - Leadership in Energy and Environmental Design (LEED) - began a pilot program that gives buildings points for having bird-friendly windows.
"So-called green buildings . . . are never green to me, no matter what their LEED award, if they kill birds," Muhlenberg's Klem said.
Chicago and San Francisco require that new buildings and major renovations incorporate bird-safe elements.
Minnesota requires that all state buildings turn off lights during migration. Michigan's governor issues an annual proclamation declaring migration "safe passage" dates and asking that buildings remain unlit at night.
A year ago, Illinois Congressman Mike Quigley introduced national legislation, still pending, to mandate bird-friendly construction for federal buildings.