Sadly, today, a Downy Woodpecker collided with the sheet glass windows of a building in our neighborhood.  It's a sickening event to endure.  The thud and then the bird laying in pain on the grass.  It died from the massive trauma.  Migration is occurring now.  Please take time to reduce this problem by making your window surfaces less confusing to migrating and breeding birds.

http://eartheasy.com/blog/2010/02/9-ways-to-help-birds-avoid-window-collisions/