Survival estimates of Antarctic terns (Sterna vittata bethunei) on the Snares Islands, New Zealand
|Title||Survival estimates of Antarctic terns (Sterna vittata bethunei) on the Snares Islands, New Zealand|
|Publication Type||Journal Article|
|Year of Publication||2007|
|Authors||Sagar, PM, Miskelly, CM, Scofield, RP, Sagar, JL|
|Type of Article||article|
|Keywords||Antarctic tern, Laridae, mortality, New Zealand, predator-free, Snares Islands, Sterna vittata|
The survival of adult and fledgling Antarctic terns (Sterna vittata bethunei) at the subantarctic Snares Islands was studied from 1976 to 2007. Annual adult survival was 0.91 and that of birds banded as fledglings was 0.42 in the first year and 0.94 in subsequent years. On average, a breeding adult would have a reproductive life-span of 10.2 years while a fledgling that survived the first year would have a life expectancy of 17.4 years. The disparity between the survival of birds banded as breeding adults and fledglings is probably be due to relatively small samples sizes. The estimated survival rates of Antarctic terns are similar to those reported for New Zealand fairy terns (S. nereis davisae). No terrestrial predators occur at the Snares Islands, and extensive predator-control is undertaken in the areas where New Zealand fairy terns nest, and so these survival rates may be typical of other breeding terns in the absence of terrestrial predators.