LC
Wilson's Storm-petrel Oceanites oceanicus



Justification

Justification of Red List Category
This species has an extremely 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 appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely 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.

Population justification
Brooke (2004) estimated the global breeding population to number 4,000,000-10,000,000 breeding pairs, equating to 12,000,000-30,000,000 individuals.

Trend justification
The population is suspected to be stable in the absence of evidence for any declines or substantial threats.

Distribution and population

The breeding range of Wilson's Storm-petrel includes subantarctic islands from Cape Horn (Chile) east to the Kerguelen Islands (French Southern Territories), and also includes coastal Antarctica. The species undergoes trans-equatorial migration, spending the off-season in the middle latitudes of the north Atlantic and north Indian Ocean. A lower number of individuals also migrate to the Pacific.

Ecology

Wilson's Storm-petrel breeds on rocky islets, on cliffs and amongst boulder scree. It feeds in cold waters over continental shelves or inshore, with a diet of comprised mainly of planktonic crustaceans (especially krill) and fish (del Hoyo et al. 1992). Its diet shifts from mainly crustaceans during egg formation to an increased proportion of fish during chick-rearing and moulting (Quillfeldt et al. 2005).

Threats

This species is under threat from invasive predators. On the Kerguelen and Crozet Islands, rats are reported to take chicks and eggs, causing nest failure, and cats may take adults in addition to chicks (Carboneras et al. 2018, Department of the Environment 2018).

Acknowledgements

Text account compilers
Ekstrom, J., Fjagesund, T., Calvert, R., Butchart, S., Hermes, C., Martin, R., Stuart, A.


Recommended citation
BirdLife International (2021) Species factsheet: Oceanites oceanicus. Downloaded from http://www.birdlife.org on 22/01/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/01/2021.