CR
Laysan Duck Anas laysanensis



Taxonomy

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
- B1ac(iv) B1ac(iv); D1+2

Red List history
Year Category Criteria
2018 Critically Endangered B1ac(iv)
2016 Critically Endangered B1ac(iv)
2015 Critically Endangered B1ac(iv)
2013 Critically Endangered B1ac(iv)
2012 Critically Endangered B1ac(iv)
2010 Critically Endangered B1a+c(iv)
2009 Critically Endangered B1a+c(iv)
2008 Critically Endangered
2006 Critically Endangered
2004 Critically Endangered
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency Does not normally occur in forest
Land mass type Average mass -
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 2 medium
Number of locations 2 -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 500-680 good estimated 2010
Population trend Increasing good observed -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 1-19 - - -
Decline (10 years/3 generation past and future) 1-19 - - -
Number of subpopulations 2 - - -
Largest subpopulations 1-89 - - -
Generation length (yrs) 6.5 - - -

Population justification: The total population on Laysan Island was estimated at 521 birds (95% CI: 492-549) in 2010, with probably over 400 individuals (between 268 and 473) on Midway in 2010 (M. Reynolds in litt. 2011). Twenty-eight individuals were translocated to Kure Atoll in 2014. This suggests that the population numbers c.500-680 mature individuals in total.

Trend justification: The population on Laysan Island has increased gradually since a low during the early 20th century, owing to the eradication of invasive alien taxa; however, it has fluctuated between 100 and ~700 birds in the last two decades. Population estimates for the species on Laysan Island indicate that it had been increasing between 1994 and 2010, although apparently the trend has not been consistent (Seavy et al. 2009, M. Reynolds in litt. 2011); however, the species appears to have suffered a c.50% decline in its adult population on Laysan following the winter storms and tsunami of early 2011 (J. R. Walters in litt. 2013). A second population established on Midway Atoll in 2004/2005 quadrupled in three years (Reynolds et al. 2007), but suffered a setback when over 160 birds were killed in an outbreak of avian botulism in August 2008 (M. Reynolds in litt. 2008). An outbreak of this disease has occurred every year since (M. Reynolds in litt. 2011, 2012, J. R. Walters in litt. 2011). Despite this, the overall population is estimated to have increased at a rate of under 20% over the last ten years.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
USA N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
USA Northwestern Hawaiian Islands

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Marine Coastal/Supratidal Coastal Brackish/Saline Lagoons/Marine Lakes major resident
Marine Coastal/Supratidal Coastal Freshwater Lakes suitable resident
Marine Intertidal Mud Flats and Salt Flats marginal resident
Shrubland Subtropical/Tropical Dry major resident
Altitude   Occasional altitudinal limits  

Threats & impact
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
Past, Unlikely to Return Whole (>90%) Very Rapid Declines Past Impact
Stresses
Species mortality
Climate change & severe weather Droughts Timing Scope Severity Impact
Past, Likely to Return Whole (>90%) Rapid Declines Past Impact
Stresses
Ecosystem degradation, Reduced reproductive success, Species mortality
Climate change & severe weather Habitat shifting & alteration Timing Scope Severity Impact
Future Whole (>90%) Unknown Unknown
Stresses
Indirect ecosystem effects, Ecosystem degradation
Climate change & severe weather Storms & flooding Timing Scope Severity Impact
Future Whole (>90%) Rapid Declines Medium Impact: 6
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Cenchrus echinatus Timing Scope Severity Impact
Past, Likely to Return Whole (>90%) Slow, Significant Declines Past Impact
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Clostridium botulinum Timing Scope Severity Impact
Ongoing Minority (<50%) Causing/Could cause fluctuations Low Impact: 5
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Echinuria uncinata Timing Scope Severity Impact
Ongoing Whole (>90%) Negligible declines Medium Impact: 6
Stresses
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 Majority (50-90%) Rapid Declines Past Impact
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Oryctolagus cuniculus Timing Scope Severity Impact
Past, Unlikely to Return Whole (>90%) Very Rapid Declines Past Impact
Stresses
Ecosystem degradation
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Pheidole megacephala Timing Scope Severity Impact
Ongoing Majority (50-90%) Negligible declines Low Impact: 5
Stresses
Competition
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Rattus exulans Timing Scope Severity Impact
Past, Unlikely to Return Majority (50-90%) Very Rapid Declines Past Impact
Stresses
Species mortality
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Unspecified species Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Species mortality

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food (human) Whole Adults and juveniles Wild Non-trivial Recent
Food - human - - - Non-trivial Recent
Food - human - - Non-trivial Recent
Pets Whole Adults and juveniles Wild International Trivial Recent
Pets/display animals, horticulture - - - International Non-trivial Recent
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2019) Species factsheet: Anas laysanensis. Downloaded from http://www.birdlife.org on 16/07/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/07/2019.