• Summary
• Text account
• Data table and detailed info
• Range map
• Resources

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.
Livezey, B. C. 1995. Phylogeny and evolutionary ecology of modern seaducks (Anatidae: Mergini). Condor 97(1): 233-255.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2018	Least Concern
2016	Least Concern
2013	Least Concern
2012	Least Concern
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Not Recognised

Migratory status	full migrant	Forest dependency	low
Land-mass type		Average mass	1,757 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	6,260,000 km2	medium
Extent of Occurrence (non-breeding)	21,600,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	-	suspected	-

Population justification: There is apparently no reliable estimate of this species's total population, and further research is needed.

Trend justification: The overall population trend is thought to be negative (Delany and Scott 2006), although there are mixed results from combined scoter Melanitta spp. surveys (T. Bowman in litt. 2012). According to one analysis, this species appears to have undergone a small or statistically insignificant increase over the last 40 years in North America (data from Breeding Bird Survey and/or Christmas Bird Count [CBC] [Butcher and Niven 2007]). Note, however, that these surveys cover less than 50% of the species's range in North America (Butcher and Niven 2007), and CBC data may not be reliable for tracking trends in this species, as it winters predominantly offshore, where a large proportion may not be visible to shore-based observers (T. Bowman in litt. 2012).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Bermuda (to UK)	extant	vagrant
Canada	extant	native	yes			yes
Greenland (to Denmark)	extant	vagrant
Mexico	extant	native			yes
St Pierre and Miquelon (to France)	extant	native	yes
USA	extant	native		yes

Country/Territory	IBA Name
Canada	Cumshewa Inlet north to Sheldens Bay
Canada	Old Crow Flats
Canada	Prince Edward County South Shore
Canada	West End of Lake Ontario
USA	Kachemak Bay
USA	Prince William Sound

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Boreal	suitable	breeding
Grassland	Tundra	suitable	breeding
Marine Neritic	Macroalgal/Kelp	major	non-breeding
Marine Neritic	Seagrass (Submerged)	major	non-breeding
Marine Neritic	Subtidal Loose Rock/pebble/gravel	major	non-breeding
Marine Neritic	Subtidal Rock and Rocky Reefs	major	non-breeding
Marine Neritic	Subtidal Sandy	major	non-breeding
Marine Neritic	Subtidal Sandy-Mud	major	non-breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	major	breeding
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Fishing & harvesting aquatic resources - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Climate change & severe weather	Other impacts	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects
Energy production & mining	Oil & gas drilling	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species disturbance, Ecosystem degradation, Ecosystem conversion
Human intrusions & disturbance	Recreational activities	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species disturbance, Reduced reproductive success
Pollution	Industrial & military effluents - Oil spills	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Indirect ecosystem effects, Ecosystem degradation, Reduced reproductive success, Species mortality
Pollution	Industrial & military effluents - Type Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance

Purpose	Scale
Pets/display animals, horticulture	international
Sport hunting/specimen collecting	subsistence, national

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Recommended citation
BirdLife International (2025) Species factsheet: White-winged Scoter Melanitta deglandi. Downloaded from https://datazone.birdlife.org/species/factsheet/white-winged-scoter-melanitta-deglandi on 25/01/2025.
Recommended citation for factsheets for more than one species: BirdLife International (2025) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 25/01/2025.