This is the largest study of it's kind, and a fascinating read.

The study found that artificial light is a top indicator of where birds will land, and in the case of city lights, it can be a deadly trap for them.
Migration is a risky and exhausting time in a bird’s life. Birds migrate hundreds to thousands of miles – sometimes burning half their body mass along the way. Finding a good place to rest and refuel is critical for migrating birds to survive and thrive once they reach their destination.
Read the full article here.