CR
Townsend's Shearwater Puffinus auricularis



Taxonomy

Taxonomic note
P. auricularis (del Hoyo and Collar 2014) is retained as a separate species from P. newelli (which see) (Handbook of the Birds of the World and BirdLife International 2018), following a revision of the scoring of parsed characters for these taxa plus P. myrtae (Handbook of the Birds of the World and BirdLife International 2018), split from P. newelli (del Hoyo and Collar 2014).

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.
Handbook of the Birds of the World and BirdLife International. 2018. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 3. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v3_Nov18.zip.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
B2ab(i,ii,iii,v) B2ab(i,ii,iii,v) A2bce+3bce; B2ab(i,ii,iii,v); D1

Red List history
Year Category Criteria
2018 Critically Endangered B2ab(i,ii,iii,v)
2016 Critically Endangered B2ab(i,ii,iii,v)
2015 Critically Endangered B2ab(i,ii,iii,v)
2013 Critically Endangered B2ab(i,ii,iii,v)
2012 Critically Endangered B2ab(i,ii,iii,v)
2010 Critically Endangered B2a+b(i,ii,iii,v)
2009 Critically Endangered B2a+b(i,ii,iii,v)
2008 Critically Endangered
2007 Critically Endangered
2006 Critically Endangered
2004 Critically Endangered
2000 Critically Endangered
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Average mass 323 g
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 3,200,000 medium
Extent of Occurrence breeding/resident (km2) 9 medium
Number of locations 1 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 250-999 medium estimated 2008
Population trend Decreasing poor inferred -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 1 - - -
Percentage in largest subpopulation 100 - - -
Generation length (yrs) 18 - - -

Population justification: Surveys in 2008 found fewer than 100 breeding pairs on Socorro, suggesting that even accounting for non-breeding birds the total global population may be as low as 250-999 mature individuals, and that previous at sea estimates (which were subject to a high degree of error) may have been too large (J. Martínez-Gomez in litt. 2008). This estimate equates to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend justification: A rapid population decline over the last three generations is estimated from surveys carried out since 1980, but exact trends are difficult to determine owing to inconsistencies between estimates of the breeding population and total numbers at sea (Brooke 2004). A noticeable reduction in nesting colonies has occurred since the observations of Martínez-Gómez and Jacobsen (2004, J. Martínez-Gómez in litt. 2012). 


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
French Southern Territories V Extant
Guam (to USA) V Extant Yes
Mexico N Extant Yes Yes
Northern Mariana Islands (to USA) V Extant Yes
Panama V Extant Yes
United States Minor Outlying Islands (to USA) V Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Mexico Islas Revillagigedo
Mexico Isla Socorro

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Neritic Macroalgal/Kelp suitable non-breeding
Marine Neritic Macroalgal/Kelp suitable breeding
Marine Neritic Pelagic major non-breeding
Marine Neritic Pelagic major breeding
Marine Neritic Seagrass (Submerged) suitable non-breeding
Marine Neritic Seagrass (Submerged) suitable breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel suitable non-breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel suitable breeding
Marine Neritic Subtidal Rock and Rocky Reefs suitable non-breeding
Marine Neritic Subtidal Rock and Rocky Reefs suitable breeding
Marine Neritic Subtidal Sandy suitable non-breeding
Marine Neritic Subtidal Sandy suitable breeding
Marine Neritic Subtidal Sandy-Mud suitable non-breeding
Marine Neritic Subtidal Sandy-Mud suitable breeding
Marine Oceanic Epipelagic (0-200m) major non-breeding
Marine Oceanic Epipelagic (0-200m) major breeding
Marine Oceanic Mesopelagic (200-1000m) major non-breeding
Marine Oceanic Mesopelagic (200-1000m) major breeding
Shrubland Subtropical/Tropical High Altitude major breeding
Altitude 0 - 900 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation
Geological events Volcanoes Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Very Rapid Declines Past Impact
Stresses
Ecosystem degradation, Ecosystem conversion, Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Capra hircus Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Slow, Significant Declines Past Impact
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Felis catus Timing Scope Severity Impact
Ongoing Whole (>90%) Rapid Declines High Impact: 8
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Mus musculus Timing Scope Severity Impact
Ongoing Whole (>90%) Slow, Significant Declines Medium Impact: 7
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Named species Timing Scope Severity Impact
Future Whole (>90%) Rapid Declines Medium Impact: 6
Stresses
Reduced reproductive success
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Oryctolagus cuniculus Timing Scope Severity Impact
Ongoing Whole (>90%) Slow, Significant Declines Medium Impact: 7
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Ovis aries Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Slow, Significant Declines Past Impact
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Sus domesticus Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Very Rapid Declines Past Impact
Stresses
Ecosystem degradation, Species mortality
Pollution Excess energy - Light pollution Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality

Recommended citation
BirdLife International (2021) Species factsheet: Puffinus auricularis. Downloaded from http://www.birdlife.org on 27/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/10/2021.