The foods that most mockingbirds thrive upon are insects, berries, and seeds. Nearly half of a mockingbirds diet is comprised of beetles, ants, grasshoppers, spiders, etc., and the other part of its diet is made up of plant materials.
Mockingbirds enjoy eating fruits and berries of holly, smilax, woodbine, sumac.
They also enjoy eating grapes, blackberries, and figs, the kind of stuff that's in FIG Newtons, blackberries, dogwoods, wild grapes, cedars or junipers, mulberries, virginia creeper, sumacs, black gum, elderberries, service berries, green briers, hollies, hackberries, poll meadows, persimmons, and manzanatas. Through much of the season they will eat ground-living athropods, but in season, they will also eat many fruits and berries. Their powerful leg s help them to hop through the undergrowth with ease. Predators in their own right, Galapagos mockingbirds are more often carnivorous than their mainland relatives and are equipped with longer beaks and feet. On the arid island, they feed opportunistically, using their beaks to dispatch centipedes, insects, and larvae, and to penetrate the shells of mollusks, crabs, and the eggs of other birds.