Bird mortality from striking residential windows in winter

A continent-wide survey of bird mortality in one winter at 5500 homes where birds are fed elicited reports of one or more bird deaths from 1165 people. In the sample of respondents, 0.85 birds/house/winter died through striking windows. This figure is probably high because the people sampled were avid bird-feeders who attract birds close to
windows. On the other hand, many cases of window strike deaths probably go unnoticed. Taking such considerations into account, the data support a previous estimate of 1-10 birds killed annually for every building in North America. Birds died from window strikes approximately in proportion to their abundance at feeders, and panic flights were implicated in a large proportion of strikes. The best proven solution is screening of windows.

Dunn, E. H. 1993. Bird mortality from striking residential windows in winter. Journal of Field Ornithology, 64(3):302–309.