CHECK-LIST OF COLORADO BIRDS 309 



40. Kittiwake. Rissa tridactvla. Rai-e or accidental 

 in winter. 



49. Western gull. Larus occidentalis. Pacific Coast 

 bird ; accidental in Colorado ; only one record. 



51a. American herring gull. Larus argentatus smith- 

 sonianus. Rare migrant; range, the whole of North 

 America. 



53. California gull. Larus californicus. Western 

 species ; breeds abundantly in Utah ; only three records 

 for Coloi'ado. 



54. Ring-billed gull. Larus delawarensis. Not un- 

 common 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 Cnilf 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 mi- 

 grant ; not uncommon in a few localities ; range, whole of 

 North America. 



62. Sabine's gull. Xema sabinii. Rare winter visi- 

 tant ; breeds in the arctic regions. 



69. Forster's tern. Sterna forsteri. Rare summer 

 resident; common migrant; habitat, temperate North 

 America. 



71. Arctic tern. Sterna paradis.ea. ^"ery rare migrant ; 

 but two records ; breeding habitat, circumpolar regions. 



77. Black tern. Hydrochelidon nigra surinamensis. 

 Common summer resident ; both sides of range ; habitat, 

 temperate North America ; in winter south as far as Brazil 

 and Chili. 



