The relatively recent interest in anti-bird strike window film received a significant boost with the December, 2019, passing by the New York City Council of legislation requiring bird-friendly glass in buildings throughout the city.
The law passed after an intense bird safety campaign by local and national conservation groups and with the support of a number of influential building architects.
It had been determined that the city is in a major northeast bird migration route known as the Atlantic Flyway. As a result of that and the huge number of high-rise buildings in the city with glass facades, between 90,000 and 230,000 birds die annually from flying into the buildings.
Prior to the New York City council legislation, various forms of bird-safe building standards or legislation have been adopted in the state of Minnesota; several California cities, including San Francisco and Oakland; and Toronto. San Francisco was the first city to pass bird safety legislation in 2011, although it was not a binding law. Several members of Congress have introduced legislation seeking bird-safe requirements in new federal buildings.
The issue with birds and office building glass involves location, light conditions, and time of day. Building glass and windows can appear highly reflective or completely transparent. By appearing similar to open sky, trees, and vegetation, it causes birds to mistake the space as a safe place to fly.
Most birds’ first encounters with glass are fatal as they collide with it at full flight speed. The uniqueness of bird vision is a contributing factor to this problem. While humans have eyes in the front of their heads and good depth perception, most birds’ eyes are at the sides of their heads. Thus, they have little depth perception beyond the range of their bills but extensive fields of view to the side and behind. They judge their flight speed by the passing of objects to their sides, so their focus in flight is not necessarily ahead.
So rather than designing buildings using less glass, which will not be happening, birds can be protected by “marking” the glass in some way so they perceive the windows as barriers and avoid them. One easy and cost-effective way to do this is to install anti-bird strike window film on all glass that is located in bird fly zones. These films usually have horizontal or vertical patterns that make the glass visible to birds.
In New York, the law requires 90 percent of the building envelope for the first 75 feet of a new building – or any building undergoing major alterations – to be constructed of bird-friendly materials meeting a specified design standard intended to decrease bird strikes.
The New York City bird safety law also requires the installation of the bird-friendly materials where an exterior wall envelope is adjacent to a green roof system and on certain installations that create hazards for birds, such as glass awnings, handrails, windbreak panels, acoustic barriers, and parallel glass panels.
The law relates to new construction but there is an important clause requiring architects and builders to include bird protection during any building renovation project. New York’s bird safety legislation goes into effect in December.
