Justification of Red List Category
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 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 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 150,000 individuals.
The population is suspected to be stable in the absence of evidence for any declines or substantial threats.
The Christmas Shearwater nests on remote islands in the central Pacific, from the Hawaiian Islands (U.S.A.) in the north, south to Phoenix Island (Republic of Kiribati), and east to the Marquesas Islands (French Polynesia) and Easter Island (to Chile). Outside the breeding season, it ranges across the Pacific, having been recorded off the coasts of Mexico and northern Chile in the east, to the Bonin Islands (Japan) in the west (del Hoyo et al. 1992).
This species is marine and pelagic, occurring over warm waters and generally keeping away from land except near colonies. Its diet comprises mostly of fish and squid with only minor proportions of crustaceans. Prey is caught mainly by pursuit-plunging and pursuit-diving, but also by surface-seizing. Feeding in association with other shearwaters and also noddies (Anous) has been seen. Its breeding season is variable, beginning in March in Hawaii. Individuals form colonies on slopes among rocks or in lava fields on oceanic islands (del Hoyo et al. 1992).
Nesting on remote, low-lying islands in the Pacific makes this species particularly threatened by potential future rises in sea-level resulting from climate change. The extent to which this may affect populations is unknown, but it is predicted to increase competition with other seabird species breeding on these islands, hence restricting the Christmas Shearwater’s breeding range. However, the colony on Midway Atoll suffered virtually no consequences of the main storm season, and direct impacts from storm surges and wave action was therefore considered to be a minimal concern for the species at present (Reynolds et al. 2015).
Text account compilers
Butchart, S., Calvert, R., Fjagesund, T., Hermes, C., Martin, R., Ekstrom, J., Newton, P., Stuart, A.
BirdLife International (2019) Species factsheet: Puffinus nativitatis. Downloaded from http://www.birdlife.org on 16/07/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/07/2019.