||Grey-backed Tern, Gray-backed Tern, Spectacled Tern
Onychoprion lunatus AOU checklist (1998 + supplements)
Sterna lunata Peale, 1848
||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.
||Onychoprion lunatus (del Hoyo and Collar 2014) was previously placed in the genus Sterna as S. lunata.
|Red List Category & Criteria:
||Butchart, S. & Symes, A.
||Butchart, S., Calvert, R. & Ekstrom, J.
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
|Previously published Red List assessments:|
- 2009 – Least Concern (LC) –
- 2008 – Least Concern (LC) –
- 2004 – Least Concern (LC) –
- 2000 – Lower Risk/least concern (LR/lc) –
- 1994 – Lower Risk/least concern (LR/lc) –
- 1988 – Lower Risk/least concern (LR/lc) –
|Range Description:||The Grey-backed Tern can be found in the tropical Pacific Ocean, from the Hawaiian Islands (USA) and Northern Mariana Islands (to USA) in the north, south through the Phoenix and Line Islands (Kiribati) to Fiji, and east to the Austral and Tuamoto Islands (French Polynesia). It is also found at sea throughout this area (del Hoyo et al. 1996). |
American Samoa (American Samoa); Fiji; French Polynesia; Indonesia; Kiribati; Marshall Islands; Micronesia, Federated States of ; Northern Mariana Islands; Palau; Solomon Islands; United States; United States Minor Outlying Islands
Japan; Samoa; Tuvalu
Present - origin uncertain:
Cook Islands; Nauru; Niue; Papua New Guinea; Pitcairn; Tokelau; Tonga; Vanuatu; Wallis and Futuna
|♦ Continuing decline in area of occupancy (AOO):||Unknown|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||37400|
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Continuing decline in number of locations:||Unknown|
|♦ Extreme fluctuations in the number of locations:||No|
|Range Map:||Click here to open the map viewer and explore range.|