Less than half of stunned or injured birds survive a collision with a window, research has found, pushing up estimates that more than 1 billion birds may die each year from flying into buildings in the US.
In a new study published on Wednesday in Plos One, researchers examined how many birds recovered in rehabilitative care after a building collision. Older estimates had assumed that most stunned birds would recover, but researchers found about 60% died, meaning the number killed by building strikes may be far higher than previously thought.
Building owners and residents “should treat your window, ideally by putting visual markers on the glass on the outside surface.” he said. He recommended glass murals or window markers rather than a few stickers, which were often ineffective. One Chicago study found that turning off lights at night resulted in between six and 11 times fewer bird strikes.