Collisions with windows are the second-largest human-related source of US bird mortality (after house cats), with low-rise buildings and homes responsible for most deaths.

Scott Loss of the Smithsonian Conservation Biology Institute in Washington DC and his colleagues examined 23 studies of bird collisions, allowing them to estimate that between 365 million and 988 million birds are killed every year by hitting buildings.

Despite the problem of bird strikes on skyscrapers being well publicized, the team found that these impacts represented less than 1% of deaths.

Several bird species, including the golden-winged warbler (Vermivora chrysoptera) and the painted bunting (Passerina ciris) were particularly collision-prone.

Condor 116, 8–23 (2014)