ML624767186

觀察細節

Sterna tern seen with slightly larger Common. In comparison to the latter, it showed more black on the crown, more black surrounding the eye, what appeared to be an all black bill (though occasionally I thought I saw a hint of deep red at the base of the bill, dull colored legs, it stood shorter than the Arctic, and it had only a hint of a faint carpal bar on the wing coverts. In fligh the white flight feathers contrasted nicely with the light gray coverts ( and scaps and mantle). Digiscope images attached.