Trinidad and Tobago Field Naturalists' Club         Southeastern Caribbean Bird Alert         Trinidad and Tobago Rare Bird Committee
Sandwich Tern (Sterna sandvicensis acuflavida) and Cayenne Tern (S. s. eurygnatha): Page 4 of 7
Page 1: Virgin Islands (variation)
Page 2: Virgin Islands (hybridisation)
Page 3: Aruba (hybridisation)
     Page 4: Tobago
Page 5: Brazil
Page 6: Argentina
Page 7: Argentina
Alternate adult Cayenne Tern (above; presumably of South American race eurygnatha) or hybrid Sandwich Cayenne Tern with intermediate bill colouration and alternate adult Sandwich Tern (below; presumably of North American race acuflavida) at Crown Point, Tobago, 8 August 2002. Photo © by Floyd Hayes. Both birds are moulting into basic plumage. Note the distinctly darker mantle (difficult to explain by angle of lighting) and recently moulted inner primaries of the Cayenne Tern. The yellow gape within the base of the bill of the Sandwich Tern is typical.