Birds are primarily visual creatures. Billions of years of evolution have honed avian brains and eyes to achieve extraordinary visual feats, from seeing into the ultraviolet spectrum, or in the case of raptors, picking out a small rodent from an altitude of hundreds of feet above the ground. Birds are also skilled navigators, in many cases, undertaking transglobal journeys from wintering grounds to breeding grounds and back again each year. Nothing in that rich evolutionary history, however, has prepared birds for the glass-enclosed, reflective buildings constructed by humans. When a bird sees a glass building, it often sees nothing but more sky and trees. This leads to potentially deadly collisions — some one billion birds die from building collisions in the United States each year. Here in Madison, the Audubon Society has developed a Bird Collision Corps to help document bird fatalities, and to help come up with solutions. Matt Reetz is the Executive Director of Madison Audubon.

Featured image: A sparrow killed by a window strike.
Photo by: Liz Hargreaves