Bryan's Shearwater Puffinus bryani


Taxonomic note
Puffinus bryani (del Hoyo and Collar 2014) was first described by Pyle et al. (2011).

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
C2a(i,ii) C2a(i,ii); D C2a(i,ii); D1

Red List history
Year Category Criteria
2018 Critically Endangered C2a(i,ii)
2016 Critically Endangered C2a(i,ii)
2015 Critically Endangered C2a(i,ii)
2014 Critically Endangered C2a(i,ii)
Species attributes

Migratory status full migrant Forest dependency Low
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 3,110,000
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 50-249 poor estimated 2014
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 1 - - -
Largest subpopulations 100 - - -

Population justification: The species's population size has not been quantified, but given its apparent rarity it is thought to have an extremely small population, probably numbering fewer than 250 mature individuals. The population is therefore placed in the band 50-249 mature individuals, assumed to equate to a total population of c.70-380 individuals.

Trend justification: The population is inferred to be in decline owing mainly to predation by introduced rats (Kawakami et al. 2012, Fjeldså 2013).

Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Japan N Extant Yes Yes
United States Minor Outlying Islands (to USA) N Extant Yes
USA N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Coastal/Supratidal Sea Cliffs and Rocky Offshore Islands major breeding
Marine Neritic Pelagic major resident
Altitude   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 - Rattus rattus Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Reduced reproductive success, Species mortality
Pollution Excess energy - Light pollution Timing Scope Severity Impact
Ongoing Minority (<50%) Unknown Unknown
Species mortality

Recommended citation
BirdLife International (2020) Species factsheet: Puffinus bryani. Downloaded from on 14/07/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from on 14/07/2020.