@Sheril @lisamelton even then this is only counting deaths by direct physical cause. The amount bird populations have dropped due to habitat loss and failed nests due to intensive farming and fishing destroying nest sites and decimating their prey, probably dwarfs even the toll from cats (who are mostly an urban phenomenon) and is the background that makes these other causes significant at all.
@StrangeNoises Particulate pollution from burning stuff can't help birds, either. I know nothing but imagine their lungs are pretty finely tuned by evolution in terms of optimising power/weight ratio, etc, so anything gumming them up is likely to have a disproportionate effect, more so than for ground animals where weight isn't quite so critical.
@Sheril @lisamelton