Royal Tern
Thalasseus maximus
This is a large tern, second only to the Caspian tern among terns in the Americas, but is unlikely to be confused with this "carrot-billed" giant, which has extensive dark underwing patches. Adults have an average wingspan of 130 cm (51 in) for both sexes, with a range from 125–135 cm (49–53 in). Its bill-to-tail length ranges from 45–50 cm (18–20 in) and the weight is anywhere from 350–500 g (12–18 oz). The Old World West African crested tern T. albididorsalis and greater crested tern T.
ID text from Wikipedia, CC BY-SA 4.0
Sandwich Tern
Thalasseus sandvicensis
This is a medium-large tern, 36–41 cm (14–16 in) long with an 95–105 cm (37–41 in) wingspan, which is unlikely to be confused within most of its range. The weight ranges from 200–300 g; males average slightly heavier than females, but with much overlap. The thin, sharp bill is black with a yellow tip. Its short legs are black. Its upper wings are pale grey and its underparts white, and this tern looks very pale in flight, although the primary flight feathers darken during the summer.
ID text from Wikipedia, CC BY-SA 4.0
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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Royal Tern and Sandwich Tern.