The Caspian tern, or taranui, is the largest tern in the world, with a powerful red bill and commanding presence. They breed in scattered colonies on sandy or shingle beaches and feed by diving for fish. In Māori tradition, the taranui was a messenger to the gods, carrying important meaning.
There is little evidence of Caspian terns in coastal deposits of subfossil bones in New Zealand, indicating that they may have colonised recently or had a very restricted distribution here until the early 20th century. Although widespread now, Caspian terns remain uncommon in New Zealand, with around 1300-1400 breeding pairs estimated.
Caspian terns are susceptible to nest disturbance by people, their dogs, and off-road vehicles. Southern black-backed gulls and red-billed gulls may attack eggs and chicks following disturbance by people. Like other shore-nesting birds, chicks and eggs are vulnerable to predation by introduced mammalian predators such as cats, stoats and ferrets.
Source: https://www.nzbirdsonline.org.nz/species/caspian-tern