Andy Trowbridge / White-fronted tern (Sterna striata) with fish. Ashley River, Canterbury, New Zealand. August.

Andy Trowbridge / White-fronted tern (Sterna striata) in flight. Ashley River, Canterbury, New Zealand. August.

Brent Stephenson / White fronted tern (Sterna striata) in flight returning to its nest with a fish in its bill, Muriwai, Auckland, New Zealand, October.

Brent Stephenson / White fronted tern (Sterna striata) in flight against sky, Muriwai, Auckland, New Zealand, October.

Brent Stephenson / Adult White-fronted tern (Sterna striata) in breeding plumage, panting from the heat whilst standing on a rocky shoreline. Kaiaua, Waikato, New Zealand, December.

Andy Trowbridge / White-fronted terns (Sterna striata) at breeding colony, Shag Point, Waitaki District, Otago Region, South Island, New Zealand. January.

Jonathan Harrod / White-fronted Tern (Sterna striata) male presenting a fish as part of courtship display, Avon Heathcote Estuary, Christchurch, New Zealand

Jonathan Harrod / White-fronted Tern (Sterna striata) pair mating, Avon Heathcote Estuary, Christchurch, New Zealand

Jonathan Harrod / White-fronted Tern (Sterna striata) presenting a fish as part of courtship display, Avon Heathcote Estuary, Christchurch, New Zealand

Brent Stephenson / White-fronted Tern (Sterna striata) resting on stoney beach, in breeding plumage. Panting with bill open due to heat. Kaiaua, Auckland, New Zealand, December.

Andrew Walmsley / Adult White-fronted tern (Sterna striata) preening, Kaikoura, South Island, New Zealand, February

Andrew Walmsley / White-fronted tern (Sterna striata) looking down into water, Kaikoura, South Island, New Zealand, December

Andrew Walmsley / White fronted tern (Sterna striata) yawning, Banks Peninsula, New Zealand, February

Andrew Walmsley / White-fronted tern (Sterna striata) in flight with a fish, Banks Peninsula, South Island, New Zealand, January

Tom Marshall / Juvenile White fronted tern (Sterna striata) Avon-Heathcote Estuary, South Island, New Zealand

Tom Marshall / White-fronted tern (Sterna striata) portrait, at roost, Ashley Estuary, Canterbury, New Zealand

Colin Monteath / White-fronted Tern (Sterna striata) colony, Shag Point, North Otago, New Zealand

Tom Marshall / White-fronted tern {Sterna striata} adult with fish in beak, Christchurch, South Island, New Zealand. January

Tom Marshall / White-fronted tern {Sterna striata} adult with fish in beak, Christchurch, South Island, New Zealand. January

Tom Marshall / White-fronted tern {Sterna striata} adult calling, Christchurch, South Island, New Zealand. January

Tom Marshall / White-fronted tern {Sterna striata} adult calling, Christchurch, South Island, New Zealand. January

Andrew Walmsley / White fronted tern (Sterna striata) juvenile calling for food, Christchurch, South Island, New Zealand, January

Andrew Walmsley / White fronted terns (Sterna striata) two perched, one landing, backlit, Bank's Peninsula, South Island, New Zealand, April

Barry Bland / White fronted tern {Sterna striata} in flight, Dunedin, New Zealand

Barry Bland / White fronted tern {Sterna striata} in flight with fish, Dunedin, New Zealand

Barry Bland / White-fronted tern (Sterna striata) in flight, New Zealand.

Barry Bland / White fronted tern (Sterna striata) in flight, New Zealand.

Barry Bland / White fronted tern (Sterna striata) in flight, New Zealand.