In The Wild: In the southwest the bullock oriole feasts on wheat, condalia, hackberry, dogwood, elderberry and oats. In California the Bullock eats cherries, fig, raspberry sorghum, peach, apricot, elderberry, grape and mulberry.
The northern oriole dines on mulberry, serviceberry, blackberry, blueberry, cherry, pear, garden pea, corn, grape, apple.
One specie of orioles is named the orchard oriole and lives near orchards. As you can see from the above listing, these birds do enjoy fresh fruit. There are not enough Orchard orioles to do extensive damage to fruit growers.
In The Feeder: If you have orioles in your area, they are especially fond of fresh orange halves. The oranges can be impaled on a nail on a post in your yard. You can also purchase nectar feeders which look much like the feeders used for hummers but are orange in color and take the same mixture of four parts water and one part sugar, as used in hummingbird feeders. It is possible to purchase orange flavoring to add to this mixture. Orioles will also feed on fruit jelly, suet, peanut butter and suet mixtures, fine cracked corn, millet, sunflower seeds and baked goods.