Ultraviolet patterns can make window glass visible to birds, thus preventing fatal collisions. However, it has now been shown that such windows are not likely to work for all species, but only for birds like small passerines, gulls and parrots, who have a special type of colour vision. For birds of prey, geese, pigeons and crows, these patterns should be difficult to detect. These conclusions appear today in an article by Olle Håstad and Anders Ödeen in PeerJ.
Billions of birds are killed in window collisions every year. This is one of the most important human sources of avian mortality. A popular and effective remedy is to apply stickers showing the silhouettes of birds of prey to windows. Birds avoid colliding with these stickers but one problem remains: that the birds collide with the glass in between the stickers instead. To avoid having to cover whole windows with stickers, glass must be made visible to birds in some other, and less obtrusive, way.