Jelly is one of the most effective oriole foods you can offer. Smooth grape jelly is best, but the birds will also take orange marmalade or red cherry, strawberry, apple, or raspberry jams or jellies. Offer jelly in small dishes, in a hollow orange rind, or smeared on an orange half and the orioles won’t be able to leave it alone. I like Perky-Pet because when the racoons try to get into it they end up just flipping it upside down - all the jelly runs to the "bottom" of the jar and they can't get to it. I usually put a full jar of jelly in it in the spring when the Orioles are first returning because they eat it so fast but during the summer I only put about 1/4 of a jar because otherwise the jelly seems to melt in the heat.