To date, 17 species of Laridae have been reported in Wyoming. Six of these species have know breeding populations in the state: the Ring-billed Gull (Larus delawarensis), California Gull (Larus californicus), Herring Gull (Larus argentatus), Caspian Tern (Sterna caspia), Forster's Tern (Sterna forsteri), and Black Tern (Chlidonias niger). Of these species, the California Gull is the most abundant and widespread. In 1984 approximately 7300 nests existed in Wyoming at six breeding locations consisting of 10 different colonies. In contrast, only small breeding populations have been discovered for the remaining five species. The Herring Gull is the most recent addition among Laridae know to nest in Wyoming. Likewise, two Ring-billed Bull colonies were recently found after not having been documented as breeding in the state for over 50 years.
Although some nesting colonies are threatened by habitat loss and human disturbance, most seem secure at present. Limited nesting and foraging habitat precludes establishment of large breeding populations of most Laridae in the state.
Findholt, Scott L.
"Status and distribution of the Laridae in Wyoming through 1986,"
Great Basin Naturalist: Vol. 54
, Article 6.
Available at: http://scholarsarchive.byu.edu/gbn/vol54/iss4/6