Black backed gulls.(Larus dominicanus,)
Also known as the Dominican Gull, the Black-backed Gull is familiar and widespread around NZ, as they are in other parts of the southern Hemisphere. They are very good at adapting their diet to their environment, and anything indigestible will regurgitate as rounded pellets. They are the largest and most heavily built of the New Zealand’s gulls. Original public domain image from Flickr