Our door cats have existed for millennia. Pesticides have not. I don’t think outdoor cats are the problem. Pesticides have killed most of the bug biomass in the last several decades and now birds are being affected.
I cannot understand why DDT is forbidden, but 10000x more powerful insecticides are not forbidden. WTF? Birds are dropping from the sky in Spring, because they have nothing to eat, because bugs are gone while seeds are not ready yet.
Also, air pollution makes them weak. Birds are much more sensitive to air pollution and CO2 level, because they breathe at much higher rate while they have much lower mass than land animals.
Also, air pollution makes them weak. Birds are much more sensitive to air pollution and CO2 level, because they breathe at much higher rate while they have much lower mass than land animals.