Glass windows are invisible to birds and cause up to 1 billion bird deaths annually in North America. Simple, effective solutions can dramatically reduce this preventable welfare problem.
Birds that strike windows may die instantly from the impact or suffer with broken beaks, fractured skulls, internal hemorrhage, and spinal injuries that cause prolonged suffering before death. Injured birds that appear dazed may be experiencing internal injuries that will cause a slower death over hours. Birds that appear to recover after a collision may have internal injuries that cause delayed mortality. The welfare impact of window collisions extends beyond the immediate death - the fear experienced in the final approach, the impact itself, and the suffering of birds who survive but are injured. This is a welfare issue of enormous scale - nearly a billion incidents annually - where relatively simple, inexpensive solutions are available to significantly reduce harm.