Note the source of these stats: the US Fish and Wildlife Service, not the wind power industry!
The comparison wouldn’t be quite so extreme in a country with more wind turbines, but the US does produce almost 7% of its electricity from wind.
While cats, windows and vehicles kill a lot of small birds, wind turbines (like overhead electrical cables) are hazardous to bigger birds like geese, swans and eagles. Germany, unlike Britain, paints red bands on turbine blades – which substantially reduces the hazard to birds.
For large birds, removing overhead electrical lines (by undergrounding them) would probably be more beneficial than avoiding building wind turbines