From Cornell University Bird Lab
If you were alive in 1970, 29% of breeding birds in the U.S. and Canada have disappeared within your lifetime. These data signal an urgent need to repair the very fabric of our ecosystems — and bring birds back.
Habitat loss and degradation are the biggest reasons for the rapid and staggering loss of birds across the continent. What are other leading causes of bird deaths because of humans? Every year, more than 2.6 billion birds are estimated to be killed by cats, and up to 1 billion birds are killed by window strikes in the U.S. and Canada alone. Collisions with vehicles and structures such as power lines and communications towers are additionally estimated to kill more than 300 million.