Seeing Spots

Birds face various obstacles in the urban environment. Windows are considered to be one of the largest sources of direct human-caused mortality for birds in North America. Glass, whether reflective or clear, is effectively invisible to birds. Birds collide with glass because they are trying to fly into the habitats they see beyond or reflected by the glass. It is estimated that across Canada, 16-42 million birds are killed annually by collisions with buildings [1].