Multi-step program:
1. Clip wings so birds are not inclined to fly over 3 or 4 ft fences
2. Have hanging plants
3. Fence all beds and delicate plantings and edibles behind minimum 3 ft sturdy fences. My vege garden is a 6' chain link enclosure that is 25x40.
4. Don't spend more than a dollar for anything you plant'
5. Cover all new plantings until quite large (shrubs, trees, vines) with chicken wire. This year I am leaving the figs inside their winter mulch ring. Will just open it up, clean out the hay and close it up so the chicken don't eat the figs before they are ripe.
When all else fails, give up on having a garden.
So far the only thing they have not eaten has been Calla Lily (poison), Licorice Root (poison) Rosemary, Sage, Thyme, Rue, Passion Flower and Blackberry vines w/ thorns. The most damage is from dirt bathing, and I have spent a lot on chicken wire in an effort to protect the plantings. It is an ongoing battle, and I am most grateful I don't live in town. Between the chickens and the grasshoppers I lost 90% of my gardens last year.
Good Luck