In the most comprehensive study of its kind, involving the review and analysis of almost two dozen studies and more than 92,000 records, federal scientists have found that between 365 and 988 million birds are likely killed in the U.S. each year as a result of collisions with buildings.

The study, Bird–Building Collisions in the U.S. : Estimates of Annual Mortality and Species Vulnerability was published in a peer-reviewed journal, The Condor : Ornithological Applications in Jan. 2014. It was authored by Scott R. Loss, Sara S. Loss, and Peter P. Marra of the Smithsonian Conservation Biology Institute and Tom Will of the U.S. Fish and Wildlife Service.

“Our analysis indicates that building collisions are among the top anthropogenic threats to birds and, furthermore, that the several bird species that are disproportionately vulnerable to building collisions may be experiencing significant population impacts from this anthropogenic threat,” the authors say.