• 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: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v4_Dec19.zip.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
B2ab(iii)	B2ab(iii); D	B2ab(iii); D1+2

Red List history

Year	Category	Criteria
2019	Critically Endangered	B2ab(iii)
2016	Not Recognised
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

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)	1,130,000 km2
Area of Occupancy (breeding/resident)	4 km2
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	200 mature individuals	good	estimated	2018
Population trend	increasing	-	estimated	-
Rate of change over the past 10 years/3 generations (longer of the two periods)	122%	-	-	-
Generation length	11.4 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Population is calculated as 200 adults based on counts of occupied burrows in 2018 (Fischer et al. 2019).

Trend justification: Population trend based on intermittent burrow counts (n = 20 seasons) carried out between 1978 and 2018 (Fischer et al. 2019).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
New Zealand	extant	native	yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Marine Coastal/Supratidal	Coastal Sand Dunes	major	breeding
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Slow, Significant Declines		Medium Impact: 7
		Stresses Ecosystem degradation, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Mustela erminea	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Species disturbance, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus norvegicus	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Species disturbance, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Species disturbance, Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Negligible declines		Medium Impact: 6
		Stresses Species disturbance

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Recommended citation
BirdLife International (2024) Species factsheet: Whenua Hou Diving-petrel Pelecanoides whenuahouensis. Downloaded from https://datazone.birdlife.org/species/factsheet/whenua-hou-diving-petrel-pelecanoides-whenuahouensis on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/11/2024.