LC
South Georgia Diving-petrel Pelecanoides georgicus



Taxonomy

Taxonomic note
Pelecanoides georgicus has been split into South Georgia Diving-petrel P. georgicus and Whenua Hou Diving-petrel following the application of the Tobias et al. (2010) criteria by Fischer et al. (2018) to a new form of South Georgia Diving-petrel, upon which it emerges as a species on the basis of a score of 8 in comparison with the population of P. georgicus from the South Atlantic Ocean and a score of 9 in comparison with that from the South Indian Ocean. 

There is a technical problem with the authors’ scoring of the two biometric characters, because they could be said to co-vary with the greater size of NZ birds. However, their data indicate that the bill of NZ birds is actually slightly shorter than those of birds from other populations, so the depth could be interpreted as independent of body size and the other character used. The authors appear to have used standard errors rather than standard deviations in their calculations. However, converting SE to SD yields scores of 1 as they indicated. While the scores for plumage differences in the original description are possibly on the generous side, the taxon is clearly valid, but much more study is needed to demonstrate the strength and consistency of the diagnostic characters. With these reservations, its status as a species is nonetheless accepted here.

Taxonomic source(s)
Fischer, J.H., Debski, I., Miskelly, C.M., Bost, C.A., Fromant, A., Tennyson, A.J., Tessler, J., Cole, R., Hiscock, J.H., Taylor, G.A. and Wittmer, H.U. 2018. Analyses of phenotypic differentiations among South Georgian Diving Petrel (Pelecanoides georgicus) populations reveal an undescribed and highly endangered species from New Zealand. PloS one 13(6): e0197766.
Handbook of the Birds of the World and BirdLife International. 2019. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 4. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v4_Dec19.zip.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2019 Least Concern
Species attributes

Migratory status not a migrant Forest dependency Does not normally occur in forest
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 16,300,000
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 12000000 poor suspected 2004
Population trend Decreasing suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations - - -
Largest subpopulations - - -
Generation length (yrs) 11.4 - - -

Population justification: Brooke (2004) estimated the global population to number around 6,000,000 pairs and 15,000,000 individuals. The Whenua Hou Diving-petrel Pelecanoides whenuahouensis was split from this species in 2018 (Fischer et al. 2018), but considering that P. whenuahouensis is thought to number 200 individuals, the impact this split has on the population data of P. georgicus would be negligible.

Trend justification: The population is suspected to be in decline owing to predation by invasive species (de Hoyo et al. 1992), and other ongoing threats.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Antarctica V Extant Yes
Australia V Extant Yes
Falkland Islands (Malvinas) U Extant Yes
French Southern Territories N Extant Yes
Heard Island and McDonald Islands (to Australia) N Extant Yes
South Africa N Extant Yes
South Georgia & the South Sandwich Islands N Extant Yes
St Helena (to UK) U Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
French Southern Territories Île de la Possession
French Southern Territories Île de l'Est
French Southern Territories Île aux Cochons
South Georgia & the South Sandwich Islands South Georgia - mainland, islands, islets and stacks
Heard Island and McDonald Islands (to Australia) Heard and McDonald Islands

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Coastal/Supratidal Coastal Sand Dunes suitable breeding
Marine Coastal/Supratidal Sea Cliffs and Rocky Offshore Islands major breeding
Marine Neritic Macroalgal/Kelp suitable resident
Marine Neritic Pelagic major resident
Marine Neritic Seagrass (Submerged) suitable resident
Marine Neritic Subtidal Loose Rock/pebble/gravel suitable resident
Marine Neritic Subtidal Rock and Rocky Reefs suitable resident
Marine Neritic Subtidal Sandy suitable resident
Marine Neritic Subtidal Sandy-Mud suitable resident
Marine Oceanic Epipelagic (0-200m) major resident
Marine Oceanic Mesopelagic (200-1000m) major resident
Rocky areas (eg. inland cliffs, mountain peaks) major breeding
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem conversion
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Reduced reproductive success

Recommended citation
BirdLife International (2020) Species factsheet: Pelecanoides georgicus. Downloaded from http://www.birdlife.org on 23/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/09/2020.