• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2019	Least Concern

Migratory status	not a migrant	Forest dependency	Does not normally occur in forest
Land mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence breeding/resident (km2)	16,300,000
Number of locations		-
Severely Fragmented		-

	Value	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		-	-	-
Percentage in largest subpopulation		-	-	-
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	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

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

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

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

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Recommended citation
BirdLife International (2023) Species factsheet: Pelecanoides georgicus. Downloaded from http://www.birdlife.org on 02/04/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 02/04/2023.