Yes, I know that it's fun to watch a bird feeder. But maybe you'd like to plant a few California natives and watch the show from outside? Above, berries of Sambuccus mexicana (blue elderberry), a native multi-trunked tree that grows fast and produces lots of berries if in sunlight. It will grow in shade but doesn't produce much. I'm cutting mine back to the ground each fall because I don't have room for a full tree, but it's back to 12 feet by April. Sun or shade, dry or a little water.
Also stunning in late summer and fall is Rhamnus californica (Coffeeberry). Several cultivars are available in the trade so you can choose a smaller or larger shrub. While this plant loses a few leaves in summer, it is actually evergreen and offers a nice resting place for the eye wherever you put it. Mine doesn't get as many berries as above, maybe it's the lack of sunshine. Sun or shade, low to moderate water.
Not quite ready are the berries of Heteromeles arbutifolius (toyon), a taller shrub than most coffeeberries. But in fall, the red berries will attract birds and add some color to the garden. The 'Davis Gold' cultivar has bright yellow berries, I love the one I have in my front garden. Sun or part shade, dry or some water. I found that in the first year, my Toyon got all manner of leaf discoloration and other strange diseases, but after it got through that it became healthy and very unfussy.
Many other California native plants offer birds tasty treats. Maybe you'd like to plant a grape? Or watch the birds sit on the stems of Festuca californica and pick little bugs off. So sit down with a nice cup of tea and enjoy the show!