Hierarchy of Threats
Each year, an estimated 1.5 - 2 billion migratory birds are killed across North America as a direct result of human activity.
Bird-building collision fatalities are second only to the impacts of habitat destruction brought about by changes in forestry, agriculture, urban development, climate change, and invasive species. Many of these birds are species at risk who can ill-afford this additional stress.
Click here to see a bar chart that illustrates the magnitude of the threats facing migratory birds. Some of the threats, like wind turbines, are relatively recent, but already significant. We can only expect that the numbers of migratory bird deaths will continue to increase as our urban environment continues to grow, unless we all work together to minimize our human footprint.