Sterna nereis (Gould, 1843)
Sternula nereis ssp. nereis Christidis and Boles (2008)
||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International.
||Sternula nereis (del Hoyo and Collar 2014) was previously placed in the genus Sterna.
||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'.
|Red List Category & Criteria:
||Butchart, S. & Symes, A.
||Baker, P., Barré, N., Burbidge, A.H., Burbidge, A., Christidis, L., Ford, H., Garnett, S., Herman, K., Holmes, D., Lacey, G., Menkhorst, P., Paton, D. & Saunders, D.
||Anderson, O., Butchart, S., Calvert, R., Ekstrom, J., Garnett, S., Harding, M., Mahood, S. & McClellan, R.
This species is classified as 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.
|Previously published Red List assessments:|
- 2010 – Vulnerable (VU)
- 2008 – Vulnerable (VU)
- 2004 – Least Concern (LC)
- 2000 – Lower Risk/least concern (LR/lc)
- 1996 – Vulnerable (VU)
- 1994 – Vulnerable (VU)
- 1988 – Near Threatened (NT)
|Range Description:||Sternula nereis occurs in Australia (subspecies nereis), New Caledonia (to France) (exsul) and northern New Zealand (davisae). In Australia, subspecies nereis may number less than 5,000 mature individuals at up to 170 sites, with less than 1,600 pairs in Western Australia, a few hundred pairs in each of Tasmania and South Australia and just a few pairs in Victoria (B. Baker in litt. 2007, D. Paton in litt. 2007, A. Burbidge n litt. 2007, D. Saunders in litt. 2007). Though it may be stable in Western Australia, numbers elsewhere in Australia have declined rapidly during the last thirty years. In New Zealand, davisae plummeted to three pairs in 1983 but, due to intensive conservation efforts has increased and in 1998, totalled 25-30 birds and 8-10 pairs over three sites. In 2006 this had increased to 30-40 individuals and 10 pairs (Parrish and Honnor 1997, Taylor 2000, S. Garnett in litt. 2007). By 2011, this had increased again to 40-45 individuals and c10 pairs (P-J. Pridham in litt. 2011). In New Caledonia, exul numbers 100-200 pairs, but was formerly much more abundant (F. Hannecart per. M. Pandolfi in litt. 1999, N. Barre in litt. 2007). One small population in the Southern Lagoon of New Caledonia may be increasing (Baling et al. 2009). |
Australia; New Caledonia; New Zealand
|♦ Continuing decline in area of occupancy (AOO):||Unknown|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||11700|
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Number of Locations:||11-100||♦ Continuing decline in number of locations:||Yes|
|♦ Extreme fluctuations in the number of locations:||No|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||In Australia, subspecies nereis may number fewer than 5,000 mature individuals at up to 170 sites, with less than 1,600 pairs in Western Australia, a few hundred pairs in each of Tasmania and South Australia and just a few pairs in Victoria. In New Zealand, davisae numbers 35-40 pairs. In New Caledonia, exul numbers 100-200 pairs. The total population is best placed in the band 2,500-9,999 mature individuals.|
Trend Justification: Data indicates a decline of 23% due to, perhaps most importantly, disturbance and predation.
|Current Population Trend:||Decreasing|
|♦ Number of mature individuals:||2500-9999||♦ Continuing decline of mature individuals:||Yes|
|♦ Extreme fluctuations:||No||♦ Population severely fragmented:||No|
|♦ No. of subpopulations:||2-100||♦ Continuing decline in subpopulations:||Unknown|
|♦ Extreme fluctuations in subpopulations:||No||♦ All individuals in one subpopulation:||No|