<Li> (EM) Endemic to the mainland - a native species found only in the 48 contiguous states and their adjacent islands (There are no birds endemic to Alaska) </Li> <P> The (A) and (C) tags correspond to the codes 5 and 4 respectively of the American Birding Association . The (E), (Ex), and (I) tags describe species' status according to the AOS . The (EH) tags follow the AOS list and the (EM) tags are based on the Clements taxonomy . </P> <P> This list contains 1105 species . Of them, 135 are tagged as accidental, 95 as casual, and 57 as introduced . Thirty - three are known to be extinct and one, the thick - billed parrot, has been extirpated though a population remains in Mexico . Thirty - three living species are endemic to Hawaii and an additional 28 former endemics are known to be extinct . Fifteen species are endemic to the 48 contiguous states . </P> <P> Order: Anseriformes Family: Anatidae </P>

How many species of birds in the us