While they physically kill the most birds by volume, the biggest decrease to bird populations is the ecological destruction of the environment. The pesticides we use actually make their egg shells non viable, but for some reason none of the studies count this figure in the "birds killed" category. It would double cats.

On top of that, we have deforestation wrecking their mating areas. People like to measure forestation in ground covered squared, while ignoring that the vast majority of migratory species only mate in specific areas.

Circling back to pesticides, the food supply has been wrecked. The food that is left avaliable is often filled with chemicals still that cause diseases, make their already fragile bones even weaker, cause feather malformation, blindness, organ failure, and cause outright sterilization.

But for some reason that's not listed in the "birds killed" figure.

Cats might kill a bunch of birds, but with a figure that's as broad as 1 to 4 billion, you need to question the validity of the argument and wonder why they leave so many other factors out of these figures.

It's the same kind of thing where they shame us for individual level consumption of pollutants and plastics, while corporations greatly outweigh consumers pollution. Both are a problem, yes cats do kill a shit load of birds, but this reddit level factoid keeps getting spread around and the reap threats aren't being educated on. You can't really say they're the "number one thing killing birds" unless you're using the figures that outright ignore other important information