Many birds are already in dramatic decline from threats like forest fragmentation, southern deforestation, windmills, and cellphone towers. I doubt they’ll be able to kill off black birds and seagulls, though.
In New Zealand, The Seagull has become an endangered species, even though there are lot of them. "Because it's a species that's quite long-lived it can take 100 years before you see a significant change in the numbers. As long as the adults aren't being killed, it will be a long, slow decline. Seagulls can live up to 30 years."
http://www.stuff.co.nz/environment/10677103/Seagull-is-NZs-l...
Uh, how?
They fly into it and die since giant metal structures are not found in nature. Makes sense, right? Tens of thousands of birds can die in one night on one tower during migrations.