|Cayenne Tern (Thalasseus sandvicensis acuflavidus)
(aka Cayenne Tern Thalasseus sandvicensis eurygnathus, Sterna sandvicensis eurygnathus)
|Lagoa do Peixe, Rio Grande do Sul, Brazil
This sub-species used to be known as Cayenne Tern which been treated by some authorities as a separate species. It is now generally regarded as a sub-species of Sandwich Tern and the HBW and Birdlife International Checklist has treated the sub-species eurygnathus as a synonym of acuflavidus since the two interbreed freely in the Caribbean.
|It differs from the nominate sub-species in having an all yellow bill.|