White fronted tern.
NZ.
White-fronted terns are the most common tern species on the New Zealand coast and are often seen in large flocks. They can be difficult to tell apart from other similar-looking terns. White-fronted terns are medium-sized (40 cm long), and have a black cap that does not join the black bill (the caps of other ‘black-capped’ tern species touch the bill). Original public domain image from Flickr