The figures reported for bird strikes against windows are astonishing. It is often said that between 100 million and a billion birds die in the US each year after striking windows.
In the UK, the British Trust for Ornithology estimated a few years ago that 100 million bird strikes occurred each year, of which a third are fatal.
In 2004 the British Trust for Ornithology (BTO) said up to 100 million birds strike windows each year in the UK, and that a third of them die – a calculation based on the number of ringed birds found dead near windows.