J.G.
Christina's answer is probaby the way you'll go about protecting your home-growns. However, I had to read your question when I saw the title, as my husband's been shooting squirrels with a BBgun that are in our yard. So that's my suggestion. Yes, they're God's creatures, but they're rodents. Would you have any problem shooting a rat in your back yard?
Anyways. Maybe that's just how some of us do it in Texas. Hopefully removing the birdseed will be a quick and easy fix too.