New World orioles eat fruit, nectar and arthropods; the amount of each food source in their diet depends largely on season and region. Because of their nectar- and fruit-feeding habits, orioles are important in pollination and seed dispersal.
During the summer, which is the birds' breeding season, arthropods comprise much of an oriole's diet. The insects provide a rich source of proteins and fats while orioles care for their young. Orioles take most of their insect prey from leaves and foliage. Orioles are important in controlling nuisance and invasive species as they eat many pests, such as gypsy moths and tent caterpillars.
In spring and fall, fruit and nectar make up a much larger part of the oriole's diet. These foods are high in sugar that the bird's body easily converts to energy and fat for use during spring and fall migration. Large flocks of orioles sometimes damage fruit crops during fall migration. Most orioles overwinter in Central and South America where pollen, nectar and fruit continue to make up a large part of their diet.
New World orioles are members of the blackbird family and are typically some combination of yellow, orange and black. New and Old World orioles are an example of convergent evolution; they are not close genetic relatives but share similar behavior and appearance.