Status: Nationally Endangered
The black-fronted tern is seen from the southern tip of the North Island, and along much of the eastern South Island from Marlborough to Southland and to Stewart Island. There is an outlying population along the Buller and upper Motueka Rivers in southern Nelson. The breeding range is restricted to the South Island. While most terns are seabirds, the black-fronted tern lives and breeds inland along riverbanks and can forage out to 10 km at sea in the non-breeding season in autumn and winter (distribution map).
The black-fronted tern (Chlidonias albostriatus) also known as the riverbed tern or tarapiroe (Māori), is a medium to small tern endemic (unique) to New Zealand, measuring 28-29cm and weighing 95grams. It is unique amongst terns in that it is the only one to breed exclusively inland. They nest in colonies on open shingle or small islands in the river.
Predominantly grey plumage over most of the body with black cap extending down over the eyes to the bright red-orange beak. During the non-breeding season the black cap recedes from the bill and becomes flecked with white. The underparts and rump are white, and there is a thin white streak running along the cheeks underneath the cap. The legs are orange.
Black-fronted gulls evolved to breed on weed-free shingle islands and banks on braided rivers. Their numbers have been declining rapidly for reasonably well-understood reasons outlined here.
Several field research projects have been carried out to determine the genetics of different colonies around the South Island, the optimal conditions for creating suitable habitats and specific predators on different rivers, and ways of potentially attracting terns to managed areas.
You can help us help them by reporting sightings of nesting terns on rivers.
- 2019: Black-backed gull control on the Hurunui and Waiau Rivers
- Clarence River: Over five years more than $500,000 was spent around the three breeding colonies of black-fronted terns on conservation land neighbouring Molesworth Station between Jacks Pass and the Acheron River
- Lower Waitaki River: this island-creation project was initially setup as part of a doctoral dissertation, with follow up work ongoing. The video below is a drone flight over the research area.
Research and references
- 2021: Mayence, Incorporating food web research into a braided river adaptive management project: overview of the next five years on the Waiau Toa/Clarence River Braided Rivers Seminar presentation.
- 2020: Schlesselmann & Robertson; Longevity can mask low Nb if only Ne of mixed‑age samples is estimated in threatened and mobile species, Conservation Genetics
- 2019: Schlesselmann et al; Contrasting patterns of population structure at large and fine geographical scales in a migratory avian disturbance specialist of braided river ecosystems, Diversity and Distributions, 01 October 2019
- 2018: Schlesselmann, A. Linking science and management for effective long-term conservation: A case study of black-fronted terns/tarapirohe (Chlidonias albostriatus) Thesis, Doctor of Philosophy: University of Otago. NOTE: includes extensive literature review for further research
- 2018: Schlesselmann, A. et al; Clearing islands as refugia for black-fronted terns, New Zealand Journal of Ecology 42: 2
- 2017: Hamblin; The use of social attractants as a management tool for black-fronted terns (Braid seminar)
- 2017: Bell; Population size, breeding success and predators of black-fronted tern (Chlidonias albostriatus) in the Upper Clarence River catchment, New Zealand Notornis, 2017, 64: 154-161
- 2016: Bell; Black-fronted tern project on the Upper Clarence: predator ID, predator control, and breeding success (BRaid workshop)
- 2016: Edwards (DOC); Upper Rangitata predator control programme and results (Braid workshop)
- 2016: Hamblin; Responses of black-fronted terns to social attractants (BRaid workshop)
- 2016: Langlands; Post breeding records of SBBG, black-billed gull, black-fronted and white-fronted terns at Canterbury River-mouths 2008 – 2015 (BRaid workshop)
- 2011: O’Donnell, C.F.J., Hoare, J.M. Meta-analysis of status and trends in breeding populations of black-fronted terns (Chlidonias albostriatus) 1962-2008 New Zealand Journal of Ecology 35: 32-43
- O’Donnell Powerpoint presentation: Black-fronted tern population trends and foraging research (DOC)
- See also Ecology/further information and references