|This was during a sudden huge influx of terns, with many terns flying past one after another. This bird in question was flying past to the far right side of the boat, and may have plunged into the water to feed, but I cannot remember too clearly. I spammed a few shots of the bird before trying to quickly capture all the other terns flying past our boat. When checking back on my photos, it looked different from the other terns.
Possibly non-breeding common tern/1CY common tern?
Features: Black cap extending to nape with a bit of white on forehead. Dark reddish bill and legs. Dark tips on underside of primaries. Greyish upperwing. Deeply forked tail with tail streamers. Dark shoulders on upperwing (characteristic of 1CY common tern).
Why not Whiskered tern:
- Whiskered tern would have a short tail lacking the tail streamers.
Why not Little tern:
- The body of this bird in question seems longer, with a longer neck. Little tern seems to be more short-bodied with a shorter neck.
- Breeding plumage little tern would show the tail streamers, but the bill would be yellow and the mask would be less extensive with an eyestripe.
- Non-breeding little tern would show a less extensive mask, and also not show the tail streamers. Bill would be black as well.
Why not Aleutian tern:
- Black mask of this bird in question is too extensive. Breeding Aleutian tern would show a more extensive white forehead, and also black bill. Non-breeding Aleutian tern would show a mostly whitish crown with blackish ear-coverts and nape, and black bill.