House cats eat them, their eggs and their young. Cat lovers feed feral cats and many live in the Oakland Hills at the junction of City and parkland. Even the coyotes can't get the cats. The song birds live at the fringes of forests where they have some protection from raccoons and ather predictors by bigger predators and birds predators, the larger predictors can't penetrate the thicker thorny trees where song birds nest. But catS can. Cats are a huge problem, an unnatural nature n native species, aliens.