Good article in the Santa Rosa Press Democract about toyon, which provides a lot of food for winter birds:

"Resident and migratory birds such as quail, finches, towhees, California Thrasher, bluebirds, flickers, bluebirds, grosbeaks, waxwings, band-tailed pigeons and mockingbirds feed on them. It takes about two months for the berries to ripen, which is why they persist so long. During this period the berries ferment, a process that breaks down toxic chemicals contained in them, rendering them palatable and highly desirable as food for birds."