THE number ONE cause of the loss of our passerine birds has been predation by “domestic” cats, many gone feral. Cats are HUNTERS, all of them, as the report points out. My cat does have a bell that warns some birds, but she’s still going hunting if she goes out. In the house, the “hunting” between her and my dachshund has a less violent ending to each “hunt”.
BTW, human destruction of habitat is the number TWO cause of species lost in passerines, but number one cause for most mammal, reptile, and many other avian species, like raptors, and aquatic birds dependent on marsh or wetland habitat. Migrants are also in serious trouble, from hummingbirds to geese (an butterflies) because WE are wiping out habitat. (and yes AGW is part of that!)