The FBI's building is on a migratory path, so during the migratory season a special netting is placed over the buildings windows:
"The FBI building isn't the only LEED-certified structure to cause problems for migratory birds. Some of the more than 33,000 certified LEED buildings in the United States use glass to bring in natural light and save on energy. All that glass can confuse birds.
"A building that kills birds is not a leader in energy and environmental design," said [Annette Prince, director of the Chicago Bird Collision Monitors]"