EN
MacGillivray's Prion Pachyptila macgillivrayi



Taxonomy
IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- B2ab(v) B2ab(v)

Red List history
Year Category Criteria
2018 Endangered B2ab(v)
2016 Endangered B2ab(v)
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Average mass 159 g
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 10,800,000
Number of locations 2-5 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 100000-1000000 poor estimated 2015
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) 11.7 - - -

Population justification: The total population size is unknown, however an estimate of between 100,000 and 1 million individuals for the taxon on Gough Island (P. Ryan pers. comm. 2016) represents the vast majority of the global population, with only an estimated 150-200 breeding pairs (c.300-400 mature individuals) present on Roche Quille, Île Saint-Paul (Jiguet et al. 2007).

Trend justification: MacGillivray’s Prion are currently suffering a very high chick mortality rate as a result of nest predation by mice (Dilley et al. 2015). These levels are comparable to those for Atlantic Petrel Pterodroma incerta, another burrowing petrel species that is virtually confined to Gough and whose breeding population (although still relatively large) is declining as a result of nest predation by mice.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
St Helena (to UK) N 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
French Southern Territories Îles des Apôtres
South Africa Prince Edward Islands Special Nature Reserve
St Helena (to UK) Gough Island

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Caves and Subterranean Habitats (non-aquatic) Caves suitable breeding
Grassland Subantarctic major breeding
Marine Neritic Pelagic major non-breeding
Marine Neritic Pelagic major breeding
Marine Oceanic Epipelagic (0-200m) major non-breeding
Marine Oceanic Epipelagic (0-200m) major breeding
Altitude 0 - 300 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mus musculus Timing Scope Severity Impact
Ongoing Majority (50-90%) Very Rapid Declines High Impact: 8
Stresses
Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Very Rapid Declines Past Impact
Stresses
Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Past, Likely to Return Minority (<50%) Slow, Significant Declines Past Impact
Stresses
Species mortality

Recommended citation
BirdLife International (2021) Species factsheet: Pachyptila macgillivrayi. Downloaded from http://www.birdlife.org on 03/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/12/2021.