• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

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#.
Cramp, S. and Simmons, K.E.L. (eds). 1977-1994. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic. Oxford University Press, Oxford.
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.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2020	Least Concern
2018	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

Migratory status	full migrant	Forest dependency	Medium
Land mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence breeding/resident (km2)	16,900,000
Extent of Occurrence non-breeding (km2)	21,400,000
Number of locations		-
Severely Fragmented		-

	Value	Data quality	Derivation	Year of estimate
No. of mature individuals	175000-200000	poor	estimated	2020
Population trend	Stable		estimated	-
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)	6.5	-	-	-

Population justification: The European population is estimated at 800-900 pairs, which equates to 1,600-1,800 mature individuals (BirdLife International 2015); however Europe represents <5% of the global range. Latest wintering surveys in 2017 recorded 7,700 individuals in the eastern Canadian population (with 80% of this population found on the St. Lawrence Estuary and Gulf), with a further 500 individuals wintering in the Maritime provinces and 100 individuals in Maine (Canadian Wildlife Service Waterfowl Committee 2020). The western Canadian population has recently been estimated at 260,000 individuals, with 18,300 individuals present in the Central Interior Plateau Region (observed in 2019; Canadian Wildlife Service Waterfowl Committee 2020). The recent Partners in Flight (2019) reassessment estimates the North American population size to be 180,000 mature individuals. The Alaskan population is unknown, as surveys will usually combine Barrow's and Common Goldeneyes Bucephala clangula when counting (J-P. Savard in litt. 2020). The overall population is therefore tentatively placed in the band 175,000-200,000 mature individuals, roughly equating to 260,000-300,000 individuals, though this number requires confirmation.

Trend justification: This species was shown to have undergone a large and statistically significant increase over the last 40 years in North America (171% increase over 40 years, equating to a 28.3% increase per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). The Partners in Flight (PiF 2019) reassessment of North American birds however showed that between 1970 and 2014, the population trend was uncertain or slowly decreasing. Similarly, the recent North American Breeding Bird Survey recorded a 56% decline between 1966 and 2015, assuming a constant rate of decline (Sauer et al. 2017). Historical records also show that the population was thought to be declining by an estimated 1.26% yearly between 2000 and 2015 (Sauer et al. 2017). However, these decline rates are non-significant, with a large uncertainty in the overall population trend. Similarly, the British Columbia Coastal Waterbird Survey showed that the population had declined across the Strait of Georgia at a rate of 4.3% a year from 1999-2011 (Crewe et al. 2012), translating to over 50% decline within a 3-generation period (19.5 years; Bird et al. 2020). However, declines across the Salish Sea are not as significant (Crewe et al. 2012, G. Sorenson in litt. 2020, Ethier et al. in prep). The western Canadian population has additionally seen stability over the past two decades, with the eastern population thought to have increased by 30% between 2014 and 2017 wintering surveys (Canadian Wildlife Service Waterfowl Committee 2020). The Icelandic population generally fluctuates as the species moves throughout suitable habitat ranges, with an increase recorded between 2008-2011 in Mývatn and Laxár, a decline from 2011 to 2012, and then higher numbers seen in 2018 (Kolbeinsson et al. 2019). The European population trend is unknown (BirdLife International 2015). Thus, based on available information, localised declines and fluctuations (which are largely statistically non-significant), as well as unreliability in survey methods are thought to be unrepresentative of the overall population. The population is therefore considered to be stable throughout most of its range (Eadie et al. 2020).

Country/Territory	Occurrence status	Presence	Resident	Breeding	Non-breeding	Passage
Canada	N	Extant	Yes	Yes	Yes
Czechia	V	Extant
Faroe Islands (to Denmark)	V	Extant
France	V	Extant
Germany	V	Extant
Greenland (to Denmark)	N	Possibly Extinct
Iceland	N	Extant	Yes
Montenegro	V	Extant
Norway	V	Extant
Russia	V	Extant
Russia (European)	V	Extant
Serbia	V	Extant
South Korea	V	Extant
Spain	V	Extant
Svalbard and Jan Mayen Islands (to Norway)	V	Extant
United Kingdom	V	Extant
USA	N	Extant	Yes	Yes	Yes

Country/Territory	IBA Name
Iceland	Myvatn - Laxa
Iceland	Veidivotn
Iceland	Sogid -Thingvallavatn
Iceland	Brúará
Iceland	Laugarvatn - Apavatn - Bruara
Canada	English Bay and Burrard Inlet
Canada	Jervis Inlet/McRae Islet
Canada	Mussel and Kynoch Inlet and Sheep Passage
Canada	Bonaventure Island
Canada	Banc de Carleton
Canada	Shigawake-Newport
Canada	Pointe Saint-Pierre et île Plate
Canada	Cap d'Espoir
Canada	Barachois de Malbaie
Canada	Baie de Gaspé
Canada	Péninsule de Forillon
Canada	Îles Les Boules
Canada	Marais de Pointe-au-Père
Canada	Marais de Gros-Cacouna
Canada	Île aux Basques et Les Razades
Canada	Baie Comeau
Canada	Baie des Escoumins et Grandes-Bergeronnes
Canada	Tadoussac
Canada	Batture Batture aux Alouettes and mouth of Saguenay River
Canada	Baie des Rochers
Canada	La Malbaie–Pointe-au-Pic
Canada	Île aux Hérons Migratory Bird Sanctuary
Canada	Canal de Beauharnois
USA	To be deleted after testing
USA	Glacier Bay & Icy Strait
USA	Prince William Sound
Iceland	Oxarfjordur

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Boreal	suitable	breeding
Forest	Temperate	suitable	breeding
Marine Coastal/Supratidal	Coastal Brackish/Saline Lagoons/Marine Lakes	suitable	non-breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	major	non-breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	major	breeding
Altitude	0 - 3000 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Wood & pulp plantations - Agro-industry plantations	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion, Reduced reproductive success
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses 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
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Salvelinus fontinalis	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Dendroctonus ponderosae	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation
Natural system modifications	Fire & fire suppression - Increase in fire frequency/intensity	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species disturbance, Ecosystem degradation, Ecosystem conversion
Pollution	Industrial & military effluents - Oil spills	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Indirect ecosystem effects, Species mortality
Residential & commercial development	Tourism & recreation areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species disturbance

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

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Recommended citation
BirdLife International (2022) Species factsheet: Bucephala islandica. Downloaded from http://www.birdlife.org on 16/08/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/08/2022.