All species › Waders, gulls and terns › Skimmers, noddies, terns and gulls › Comparing terns
Comparing terns
All the terns in the guide side by side, for use in the field. Pick what you see (bill, legs, head, tail, mantle, underparts) and the table keeps what fits.
Size
Legs
Head in breeding plumage
Head in winter plumage
Tail
Mantle
Underparts
Where
Scroll the table sideways to see all columns.
| Species | Size | Bill | Legs | Head in breeding plumage | Head in winter plumage | Tail | Mantle | Underparts | Where | What to look for |
|---|---|---|---|---|---|---|---|---|---|---|
| Aleutian TernOnychoprion aleuticus | medium (30–40 cm) | black | black or dark | black cap with a white forehead | white forehead, black rear crown | forked | medium grey | pale to medium grey | coast and open sea | Note the grey underparts contrasting with a white tail, and the dark bar along the trailing edge of the secondaries. |
| Sooty TernOnychoprion fuscatus | large (> 40 cm) | black | black or dark | black cap with a white forehead | little different from breeding | long and deeply forked | dark grey or blackish | white | coast and open sea | Look for a sooty-black back without a pale collar, and a white forehead patch that stops above the eye; on Bridled it extends behind. |
| Gray-backed TernOnychoprion lunatus | medium (30–40 cm) | black | black or dark | black cap with a white forehead | little different from breeding | long and deeply forked | medium grey | white | coast and open sea | Look for a slate-grey rather than brownish-black back without a pale collar, and a narrow white eyebrow reaching past the eye. |
| Bridled TernOnychoprion anaethetus | medium (30–40 cm) | black | black or dark | black cap with a white forehead | little different from breeding | long and deeply forked | dark grey or blackish | white | coast and open sea | Note the brownish-grey back, paler than the black cap, with a pale collar and a white eyebrow that extends behind the eye. |
| Least TernSternula antillarum | small (< 30 cm) | yellow with a black tip | yellow or yellow-orange | black cap with a white forehead | white forehead, black rear crown | forked | pale grey | white | coast and inland | Note the tiny size, yellow bill with a black tip and the white triangle in the black cap; flies with fast, stiff wingbeats. |
| Caspian TernHydroprogne caspia | large (> 40 cm) | red or orange with a black tip | black or dark | black cap | little different from breeding | short, barely forked | pale grey | white | coast and inland | Look for the thick, bright red bill and dark undersides to the primaries; Royal Tern has a slimmer orange bill and pale underwings. |
| Gull-billed TernGelochelidon nilotica | medium (30–40 cm) | black | black or dark | black cap | white head with a dark ear spot | short, barely forked | very pale grey | white | coast and inland | Watch for the short, thick, all-black bill without a yellow tip and the broad wings; it often hunts insects over land and marsh. |
| White-winged TernChlidonias leucopterus vagrant | small (< 30 cm) | black | red | head and body black | white head with a dark ear spot | short, barely forked | dark grey or blackish | black or very dark | inland waters and marsh | Look for white forewings, a white rump and black underwing coverts; Black Tern has pale underwings and a grey tail. |
| Black TernChlidonias niger | small (< 30 cm) | black | black or dark | head and body black | white forehead, black rear crown | short, barely forked | medium grey | black or very dark | inland waters and marsh | Note the slate-grey wings and tail, pale underwings and white undertail; in winter, a dark smudge on the side of the breast. |
| Sandwich TernThalasseus sandvicensis | medium (30–40 cm) | black with a yellow tip | black or dark | black cap with a shaggy crest | white forehead, black rear crown | forked | very pale grey | white | coast and open sea | Look for the long, slender black bill with a yellow tip; Gull-billed Tern has a shorter, thicker, all-black bill. |
| Elegant TernThalasseus elegans | large (> 40 cm) | orange, without a black tip | black or dark | black cap with a shaggy crest | white forehead, black rear crown | forked | very pale grey | white with a pink flush | coast and open sea | Watch for the long, thin, slightly drooping bill and long crest; in winter the black still surrounds the eye. |
| Royal TernThalasseus maximus | large (> 40 cm) | orange, without a black tip | black or dark | black cap with a shaggy crest | white forehead, black rear crown | forked | very pale grey | white | coast and open sea | Note the thick orange dagger bill and pale underwings; Elegant Tern has a longer, thinner, slightly drooping bill. |
| Forster's TernSterna forsteri | medium (30–40 cm) | red or orange with a black tip | orange | black cap | black eye mask on a white head | long and deeply forked | very pale grey | white | coast and inland | Look for silvery-white primaries, paler than the rest of the wing, and in winter a separate black eye mask on a white head. |
| Arctic TernSterna paradisaea | medium (30–40 cm) | red | red | black cap | white forehead, black rear crown | long and deeply forked | pale grey | pale to medium grey | coast and open sea | Note the blood-red bill without a black tip, short legs, round head and translucent primaries with a narrow black trailing edge. |
| Common TernSterna hirundo | medium (30–40 cm) | red or orange with a black tip | red | black cap | white forehead, black rear crown | forked | pale grey | white | coast and inland | Look for a dark wedge in the outer wing, an orange-red bill with a black tip and a tail not extending past the folded wingtips. |
| Roseate TernSterna dougallii | medium (30–40 cm) | black with a red base | red | black cap | white forehead, black rear crown | long and deeply forked | very pale grey | white with a pink flush | coast and open sea | Watch for very pale upperwings with only the outer primaries dark, a mostly black bill and tail streamers far beyond the wingtips. |
No species fits this combination. Remove a filter.
The features describe the adult, in breeding and winter plumage where these differ. Juveniles are much harder and do not belong in a table like this; see the species pages for those.