LC
Lesser Scaup Aythya affinis



Taxonomy

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: #http://www.aerc.eu/DOCS/Bird_taxa_of _the_WP15.xls#.
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.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm#.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2021 Least Concern
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

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

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 11,000,000 medium
Extent of Occurrence non-breeding (km2) 19,100,000 medium
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 3700000 poor estimated 2018
Population trend Stable 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) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 5.5 - - -

Population justification: The global population is estimated to number 3,700,000 mature individuals and is currently stable (Meehan et al. 2018, Pardieck et al. 2018, Partners in Flight 2020).

Trend justification: The species is considered to have undergone a historical decline (Partners in Flight 2020, Wetlands International 2020), but recent North American Breeding Bird Survey and Christmas Bird Count data appears to show that the species has been roughly stable in the short-term (Meehan et al. 2018, Pardieck et al. 2018). Therefore, the species is assessed here as being stable.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Anguilla (to UK) N Extant Yes
Antigua and Barbuda V Extant
Aruba (to Netherlands) N Extant Yes
Bahamas N Extant Yes
Barbados N Extant Yes
Belize N Extant Yes
Bermuda (to UK) N Extant Yes
Bonaire, Sint Eustatius and Saba (to Netherlands) N Extant Yes
Canada N Extant Yes Yes Yes Yes
Cayman Islands (to UK) N Extant Yes
Colombia N Extant Yes
Costa Rica N Extant Yes
Cuba N Extant Yes
Curaçao (to Netherlands) N Extant Yes
Denmark V Extant
Dominica N Extant Yes
Dominican Republic N Extant Yes
Ecuador N Extant Yes
El Salvador N Extant Yes
France V Extant
Greenland (to Denmark) V Extant
Guadeloupe (to France) N Extant Yes
Guatemala N Extant Yes
Haiti N Extant Yes
Honduras N Extant Yes
Ireland V Extant
Jamaica N Extant Yes
Japan V Extant
Martinique (to France) V Extant
Mexico N Extant Yes
Netherlands V Extant
Nicaragua N Extant Yes
Northern Mariana Islands (to USA) V Extant
Panama N Extant Yes
Portugal V Extant
Puerto Rico (to USA) N Extant Yes
Russia V Extant
Russia (Asian) V Extant
Sint Maarten (to Netherlands) N Extant Yes
Spain V Extant
St Barthelemy (to France) V Extant
St Kitts and Nevis V Extant
St Lucia N Extant Yes
St Martin (to France) N Extant Yes
St Pierre and Miquelon (to France) V Extant Yes
St Vincent and the Grenadines N Extant Yes
Suriname N Extant Yes
Trinidad and Tobago N Extant Yes
Turks and Caicos Islands (to UK) N Extant Yes
United Kingdom V Extant
USA N Extant Yes Yes Yes Yes
Venezuela N Extant Yes
Virgin Islands (to UK) N Extant Yes
Virgin Islands (to USA) N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Mexico Presa Temascal
Jamaica Yallahs
Canada Netley-Libau Marsh
Canada Oak Lake/Plum Lakes Area
Canada Whitewater Lake
Canada Langruth - Rm of Lakeview
Canada St. Mary's River Complex (Echo Bay ON to Maxton Bay MI)
Canada Moose River Estuary
Canada Barber Lake
Canada Eyebrow Lake
Canada Manitou Lake Area (includes Reflex, Freshwater, Wells, Colette and Cipher Lakes)
Canada Old Crow Flats
Bahamas Southern Great Lake
Dominican Republic Cabral Lagoon
Virgin Islands (to USA) Southgate and Green Cay
Cayman Islands (to UK) Central Mangrove Wetland
Cayman Islands (to UK) Crown Wetlands
Jamaica Black River Great Morass
Mexico Los Tuxtlas
Mexico Pantanos de Centla
Puerto Rico (to USA) Guaniquilla and Boquerón
Mexico Subcuenca Tecocomulco
USA Lake Pontchartrain
Colombia Laguna de la Cocha

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Aquatic & Marine Artificial/Aquatic - Water Storage Areas (over 8ha) suitable non-breeding
Marine Coastal/Supratidal Coastal Brackish/Saline Lagoons/Marine Lakes suitable non-breeding
Marine Coastal/Supratidal Coastal Freshwater Lakes suitable non-breeding
Marine Neritic Estuaries suitable non-breeding
Marine Neritic Macroalgal/Kelp suitable non-breeding
Marine Neritic Seagrass (Submerged) suitable non-breeding
Marine Neritic Subtidal Loose Rock/pebble/gravel suitable non-breeding
Marine Neritic Subtidal Rock and Rocky Reefs suitable non-breeding
Marine Neritic Subtidal Sandy suitable non-breeding
Marine Neritic Subtidal Sandy-Mud suitable non-breeding
Wetlands (inland) Permanent Freshwater Lakes (over 8ha) suitable non-breeding
Wetlands (inland) Permanent Rivers/Streams/Creeks (includes waterfalls) suitable breeding
Wetlands (inland) Permanent Saline, Brackish or Alkaline Lakes suitable breeding
Wetlands (inland) Seasonal/Intermittent Freshwater Lakes (over 8ha) suitable breeding
Wetlands (inland) Seasonal/Intermittent Saline, Brackish or Alkaline Lakes and Flats suitable breeding
Altitude   Occasional altitudinal limits  

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2023) Species factsheet: Aythya affinis. Downloaded from http://www.birdlife.org on 30/03/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/03/2023.