User:EliteSpoon/Bird window collisions

Bird mortality rates increase with the amount of light that is emitted from a given building and bird species that migrate at night are particularly vulnerable to collisions, which is thought to be attributed to fatal entrapment by light-emitting structures. While there are various explanations for why nocturnally migrating birds are attracted to artificial lights, we do know that birds rely on a variety of cues for migration, with the orientation of the stars being a major reference for nocturnal migrants. It is therefore speculated that these artificially illuminated areas conceal the visual navigation cues that these birds rely on, resulting in them becoming disoriented. This hypothesis has been well supported by several observations of birds being attracted to and disoriented by lights, particularly in conditions of poor-visibility, which makes them more susceptible to colliding with buildings.

In addition, birds may also be impacted by bright lights at nights as they have extra-retinal photoreceptors that are disoriented by the reflection of light from these buildings. Mitigating the amount of light emitted from glass surfaces at night, such as windows, can reduce the amount of fatal bird collisions with buildings and structures.