VU
Red-legged Kittiwake
Rissa brevirostris
Family
Laridae
Skimmers, Noddies, Terns, and Gulls
VU 
VU
Relict Gull
Ichthyaetus relictus
LC
Ring-billed Gull
Larus delawarensis
VU
River Tern
Sterna aurantia
LC
Roseate Tern
Sterna dougallii
LC
Ross’s Gull
Rhodostethia rosea
NE
Royal Tern
Thalasseus maximus
LC
Sabine’s Gull
Xema sabini
LC
Sandwich Tern
Thalasseus sandvicensis
VU
Saunders’s Gull
Saundersilarus saundersi
LC
Saunders’s Tern
Sternula saundersi
NE
Short-billed Gull
Larus brachyrhynchus
LC
Silver Gull
Chroicocephalus novaehollandiae
LC
Slaty-backed Gull
Larus schistisagus
LC
Slender-billed Gull
Chroicocephalus genei
LC
Snowy-crowned Tern
Sterna trudeaui
LC
Sooty Gull
Ichthyaetus hemprichii
LC
Sooty Tern
Onychoprion fuscatus
LC
South American Tern
Sterna hirundinacea
LC
Spectacled Tern
Onychoprion lunatus
LC
Swallow-tailed Gull
Creagrus furcatus
NE
Vega Gull
Larus vegae
NE
West African Crested Tern
Thalasseus albididorsalis
LC
Western Gull
Larus occidentalis