One only needs to visit the Hawaiian Islands and study their ecological history to learn what a catastrophy has happened to native bird (and animal) populations when non-native species are introduced. When not slinging personal attacks at this webmaster and wasting our time, some contributors might better spend their time reading up on this, as it applies to California ecology. It seems that this, coupled with feral and outdoor roaming pets, would be a larger threat to California species of native plants, birds, and animals. Not the feeders.