Justification This species has been uplisted to Vulnerable owing to recent declines over much of its breeding range. Predation by introduced species, disturbance and inappropriate water level management are thought to have contributed most to this decline. However, data is patchy, and a clarification of trends in its strongholds may lead to its status being revised.

Family/Sub-family Laridae

Species name author (Gould, 1843)

Taxonomic source(s) Christidis and Boles (1994), Christidis and Boles (2008), Sibley and Monroe (1990, 1993), Turbott (1990)

Synonyms Sternula nereis Christidis and Boles (2008)

Taxonomic note The BirdLife Taxonomic Working Group is aware that phylogenetic analyses have been published which have proposed generic rearrangements which may affect this species, but prefers to wait until work by other taxonomists reveals how these changes affect the entire groups involved.

Identification 25 cm. Very small white and grey tern with black cap. Upperparts pale grey; white forked tail; underparts white; legs orange-yellow; bill yellow-brown; white forehead with black crown, nape and line to eye. Similar species: Very similar to Little Tern S. albifrons except upperwings more uniformly grey and forehead steep. Hints: . Voice: Flight call high pitched 'zwitt'.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

2,500-9,999

decreasing

11,700 km²

No

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: It breeds on sheltered mainland coastlines and close islands, usually on sandy beaches above the high tide line but below where vegetation occurs¹³. Breeding occurs at different times at different locations, but generally occurs from mid to late October until February¹³. Adults have been observed to conduct post-fledgling parental care in New Zealand¹². It feeds almost entirely on fish mainly by following shoals of feeding predatory fish, and are rarely found out of sight of land¹³. It lays one or two eggs. The oldest recorded individuals are at least 13 (New Zealand) and 17 years (Australia). Observations over one season on New Caledonia revealed a low rate of nesting success, with only one in five nests producing a fledgling¹¹.

Threats Threats include habitat degradation by encroaching weeds and housing developments, predation by introduced mammals and gulls, extreme weather events (which locally at least can put an entire breeding season at risk)², and disturbance by humans (particularly tourists in New Caledonia), dogs and vehicles, either causing the direct destruction of eggs or desertion of nests^2,3,4. In South Australia inappropriate water level management has lead to a collapse in the numbers of prey fish, and a subsequent decline in colonies⁶.

Conservation measures underway Many colonies in Australia are regularly monitored, and intensive management has led to an increase in the population on New Zealand.

Conservation measures proposed Monitor all breeding colonies annually to assess trends. Control introduced mammals and other nest predators at important breeding sites. Oppose developments which would encroach on breeding colonies. Restrict access to important breeding colonies.

References 1. Taylor (2000). 2. Parrish and Honnor (1997). 3. F. Hannecart per. M. Pandolfi in litt. (1999). 4. Higgins and Davies (1996). 5. B. Baker in litt. (2007). 6. D. Paton in litt. (2007). 7. A. Burbidge n litt. (2007). 8. D. Saunders in litt. (2007). 9. S. Garnett in litt. (2007). 10. N. Barre in litt. (2007). 11. Baling et al. (2009). 12. Preddey (2008). 13. Higgins and Davies (1996).12. Preddey (2008)

Text account compilers Stuart Butchart (BirdLife International), Rob Calvert (BirdLife International), Jonathan Ekstrom (BirdLife International), Stephen Garnett (Charles Darwin University), Matt Harding (BirdLife International), Simon Mahood (BirdLife International), Rachel McClellan (BirdLife International)

Contributors Paul E Baker (US Fish & Wildlife Service), Nicholas Barré (Société Calédonienne d’Ornithologie), Allan Burbidge (Department of Environment & Conservation, WA), Andrew Burbidge (Department of Environment & Conservation, WA), Les Christidis (Museum Victoria), Hugh Ford (Dept of Zoology, University of New England), Stephen Garnett (Charles Darwin University), Kerryn Herman, Derek Holmes (Indonesian Ornithological Society), Geoff Lacey, Peter Menkhorst (DSE, Victoria), David Paton (University of Adelaide), Don Saunders

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International), Rob Calvert (BirdLife International)

Recommended citation BirdLife International (2010) Species factsheet: Sterna nereis. Downloaded from http://www.birdlife.org on 30/7/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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