As much as is made of wind turbines being a threat to birds,
they don't even come close to the biggest manmade killer of
birds: buildings. Highly reflective window glass claims as many
as one billion birds a year in North America, while city lights
at night can cause migratory birds to become disoriented, often
leading to their death. San Francisco officials are hoping to
help protect the 400 different species of birds that inhabit
their city by introducing a new law called Standards for Bird-
Safe Buildings. The standards are mainly voluntary, but new
buildings, additions and retrofits, buildings near urban bird
refuges, as well as structures like freestanding clear glass
walls, skywalks, rooftop greenhouses and enclosed balconies do
have to comply with some mandatory rules. To make these
buildings and structures bird-safe, owners can place netting in
front of windows or place ceramic lines or dots on glass to cut
down on their reflectivity, while preserving the ability to see
out. To keep from confusing migr