Introduced species
Several common birds in the United States, such as the house sparrow, the rock pigeon, the European starling, and the mute swan are introduced species, meaning that they are not native to North America, but were brought there by humans. Introduced species are marked as (I). In addition, many non-native species which have individual escapees or small feral populations in North America are not on the list. It is especially true of birds that are commonly held as pets, such as parrots and finches.