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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable 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.
Brooke (2004) estimated the global population to number around 600,000 indviduals.
The population is declining owing to predation by invasive species.
This species has a circumpolar range and is found throughout the Southern Oceans. It breeds on Macquarie Island (Australia), the Auckland Islands and Antipodes Islands (New Zealand), Crozet and Kerguelen Islands (French Southern Territories) and possibly on the Prince Edward Islands (South Africa) (del Hoyo et al. 1992).
The White-headed Petrel is marine and highly pelagic, rarely approaching land except at colonies, but has been recorded inshore during stormy weather. It feeds mostly on squid and crustaceans, which is catches mostly at night by surface-seizing and dipping. Breeding starts in October in loose colonies, nesting in burrows dug in soft soil or scree near the coast or inland up to 300 m above sea level (del Hoyo et al. 1992).
The primary threats facing this species come from invasive predators. Extinction of the species on Auckland Island is attributed to the impact of introduced pigs and cats (Taylor 2013), and despite large numbers breeding adjacent to the main island the continued presence of both pigs and cats prevents any recolonisation effort. Cats, House Rats, European Rabbits and Weka are thought to have caused dramatic declines on Macquarie Island prior to their eradication (Taylor 2013). House Mice are present on the Antipodes, where this species breeds, but there is no data on any impact.
Text account compilers
Fjagesund, T., Butchart, S., Hermes, C., Ekstrom, J., Martin, R., Calvert, R., Stuart, A.
BirdLife International (2021) Species factsheet: Pterodroma lessonii. Downloaded from http://www.birdlife.org on 06/03/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/03/2021.