Increasing habitat loss due to growing land use has caused significant depletion of regional and national bird species. The largest decline in bird populations can be attributed to the increased use of glazing (the glass component of a building’s façade) in the built environment.
Bird injuries and deaths caused by trends in the architecture and landscape architecture are attributed to a bird’s inability to recognize glass and the proliferation of the use of artificial light during nighttime hours.
Both transparency and reflectivity are detrimental to bird life. Birds cannot recognize transparent obstructions in their flight path and also cannot distinguish real foliage from its mirrored image on reflective glass. The result is the same, bird strikes leading to injury or death.
Transparency is exacerbated by artificial light at night, since the light attracts birds to feeding or perching sites, which is also known to ornithologists as the “beacon effect.” Scientists attribute hundreds of thousands of bird deaths each migratory season to bird strikes, which equates to the loss of life to over 225 species (1/4 of the bird species in North America).
The Audubon Society is currently working with architects, landscape architects and scientists to create bird-safe building design guidelines. These guidelines consist of recommendations for local government/community actions, new approaches to site planning techniques and enhancements to fenestration systems. A few examples are as follows:
Local actions
- Documenting migratory paths and distribute them in designer guidelines.
- Promoting bird-friendly policies via zoning approvals, incentive
programs or prerequisites for public building and land development.
- Developing “lights off” or “lights dimmed” regulations with
city/township limits.
Site planning
- Reducing the use of landscaping attractive to birds for feeding,
nesting, etc. located in proximity to transparent or reflective glazing.
- Preventing new construction or greenfield sites in major bird migratory
paths.
- Reducing the use of interior trees in spaces, particularly where glazing
creates a clear path into and out of buildings.
Enhancements to fenestration
- Using exterior shading devices to reduce the reflectivity of surrounding
environments.
- Developing bird-legible patterns on glass surfaces.
- The implementation of screening devices in a plan in front of
transparency glazing.
LF Driscoll incorporates a healthy mix of these guidelines to greatly reduce the impact that architects and builders have on our bird populations. A comprehensive list of bird-safe building guidelines and case studies can be found in the NYC Audubon Society’s “Bird-Safe Building Guidelines.”