40. Kittiwake. Rissa tridactyla. Rare or accidental in winter.
49. Western gull. Larus occidentalis. Pacific Coast bird; accidental in Colorado; only one record.
51a. American herring gull. Larus argentatus smithsonianus. Rare migrant; range, the whole of North America.
53. California gull. Larus californicus. Western species; breeds abundantly in Utah; only three records for Colorado.
54. Ring-billed gull. Larus delawarensis. Not uncommon summer resident; common in migration; breeds as high as 7,500 feet; range, whole of North America.
58. Laughing gull. Larus atricilla. Bird of South Atlantic and Gulf States; once accidental in Colorado.
59. Franklin's gull. Larus franklinii. Rare migrant; range, interior of North America.
60. Bonaparte's gull. Larus philadelphia. Rare migrant; not uncommon in a few localities; range, whole of North America.
62. Sabine's gull. Xema sabinii. Rare winter visitant; breeds in the arctic regions.
69. Forster's tern. Sterna forsteri. Rare summer resident; common migrant; habitat, temperate North America.