Cygnus cygnus

Taxonomy

Assessment Information

Geographic Range

Habitat and Ecology

Threats

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	ANSERIFORMES	ANATIDAE

Scientific Name:

Cygnus cygnus

Species Authority:

(Linnaeus, 1758)

Common Name/s:

English

–

Whooper Swan

Assessment Information [top]

Red List Category & Criteria:

Least Concern ver 3.1

Year Published:

2009

Assessor/s:

BirdLife International

Reviewer/s:

Bird, J., Butchart, S.

Justification:
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

History:

2008	–	Least Concern
2004	–	Least Concern

Geographic Range [top]

Countries:	Native: Afghanistan; Albania; Armenia; Austria; Azerbaijan; Belarus; Belgium; Bosnia and Herzegovina; Bulgaria; China; Croatia; Czech Republic; Denmark; Estonia; Faroe Islands; Finland; France; Germany; Greece; Greenland; Iceland; India; Iran, Islamic Republic of; Iraq; Ireland; Italy; Japan; Kazakhstan; Korea, Democratic People's Republic of; Korea, Republic of; Kyrgyzstan; Latvia; Lithuania; Macedonia, the former Yugoslav Republic of; Mongolia; Montenegro; Nepal; Netherlands; Norway; Pakistan; Poland; Romania; Russian Federation; Russian Federation; Russian Federation; Serbia; Slovakia; Slovenia; Spain; Svalbard and Jan Mayen; Sweden; Switzerland; Taiwan, Province of China; Tajikistan; Turkey; Turkmenistan; Ukraine; United Kingdom; United States; Uzbekistan Vagrant: Algeria; Cyprus; Egypt; Hungary; Israel; Liechtenstein; Luxembourg; Portugal; Qatar; Syrian Arab Republic; Tunisia; United Arab Emirates
Range Map:	Click here to open the map viewer and explore range.

Countries:

Native:

Afghanistan; Albania; Armenia; Austria; Azerbaijan; Belarus; Belgium; Bosnia and Herzegovina; Bulgaria; China; Croatia; Czech Republic; Denmark; Estonia; Faroe Islands; Finland; France; Germany; Greece; Greenland; Iceland; India; Iran, Islamic Republic of; Iraq; Ireland; Italy; Japan; Kazakhstan; Korea, Democratic People's Republic of; Korea, Republic of; Kyrgyzstan; Latvia; Lithuania; Macedonia, the former Yugoslav Republic of; Mongolia; Montenegro; Nepal; Netherlands; Norway; Pakistan; Poland; Romania; Russian Federation; Russian Federation; Russian Federation; Serbia; Slovakia; Slovenia; Spain; Svalbard and Jan Mayen; Sweden; Switzerland; Taiwan, Province of China; Tajikistan; Turkey; Turkmenistan; Ukraine; United Kingdom; United States; Uzbekistan

Vagrant:

Algeria; Cyprus; Egypt; Hungary; Israel; Liechtenstein; Luxembourg; Portugal; Qatar; Syrian Arab Republic; Tunisia; United Arab Emirates

Range Map:

Click here to open the map viewer and explore range.

Habitat and Ecology [top]

Habitat and Ecology:	Behaviour This species is predominantly migratory¹ and travels over land making brief stop overs⁶. It breeds from mid-May in solitary pairs with well-defined territories¹ (non-breeders remaining in flocks separate from breeding pairs)². Adults undergo a post-breeding moult period between late-July and early-August when they become flightless for c.30 days² (5-6 weeks)⁵, males starting to moult before the females². Non-breeding individuals moult at the same time as breeders, but whilst breeding pairs tend to moult in their breeding territories non-breeders moult in large congregations². After moulting the species begins to migrate south from late-September to October (the precise timing determined by weather conditions)² and arrives on the wintering grounds by October or November³. The species departs for the breeding grounds again from March to April² or early-May³. Outside of the breeding season the species is highly sociable, migrating in small flocks or family groups³ and congregating into flocks of up to 300-400 individuals in the winter^{3, 4}. The species roosts on areas of open water adjacent to its feeding areas³. Habitat Breeding The species breeds on islands in or along the banks of shallow freshwater pools, lakes, slow-flowing rivers¹, marshes, swamps and bogs², showing a preference for habitats with abundant emergent vegetation² and reedbeds⁴ in taiga (coniferous forest) zones^{2, 4}, birch forest zones⁴ and shrub/forest tundra² (generally avoiding open tundra)^{1, 4}. Non-breeders may also be found in flocks² along sheltered coasts¹ on estuaries, lagoons and shallow bays during this season⁶. Non-breeding On migration the species frequents lakes, estuaries and sheltered coasts². It traditionally winters on freshwater lakes and marshes², floodlands⁶, brackish lagoons and coastal bays² although low-lying coastal agricultural land¹ and wet pastures⁶ are now used increasingly². Diet The species is predominantly herbivorous¹, its diet consisting of the leaves, stems and roots⁴ of aquatic plants (e.g. algae and Zostera, Ruppia and Potamogeton spp.), grasses¹, sedges and horsetails (Equisetum spp.)². During the winter the species also takes agricultural grain, vegetables (e.g. potatoes and turnips⁴) and acorns¹, and on the breeding grounds young birds often take adult and larval insects⁴ (e.g. emerging chironomids)². Adults may also supplement their diet with marine and freshwater mussels². Breeding site The nest is a large mound of plant matter¹ built on dry ground or in reedbeds⁴ on small islands in or along the edges of lakes, pools or rivers³. The same nest mound may be used over several years although it is often repaired and new material is added². Management information A study carried out at a wintering site in Denmark found that large wind turbines (towers 68 m high with blades 66 m in diameter, blades sweeping the heights of 35-101 m) pose less of a collision risk to the species than wind turbines of a medium height (towers 45 m high with blades 48 m in diameter, blades sweeping the heights of 21-69 m)¹².
Systems:	Terrestrial; Freshwater

Habitat and Ecology:

Behaviour This species is predominantly migratory¹ and travels over land making brief stop overs⁶. It breeds from mid-May in solitary pairs with well-defined territories¹ (non-breeders remaining in flocks separate from breeding pairs)². Adults undergo a post-breeding moult period between late-July and early-August when they become flightless for c.30 days² (5-6 weeks)⁵, males starting to moult before the females². Non-breeding individuals moult at the same time as breeders, but whilst breeding pairs tend to moult in their breeding territories non-breeders moult in large congregations². After moulting the species begins to migrate south from late-September to October (the precise timing determined by weather conditions)² and arrives on the wintering grounds by October or November³. The species departs for the breeding grounds again from March to April² or early-May³. Outside of the breeding season the species is highly sociable, migrating in small flocks or family groups³ and congregating into flocks of up to 300-400 individuals in the winter^{3, 4}. The species roosts on areas of open water adjacent to its feeding areas³. Habitat Breeding The species breeds on islands in or along the banks of shallow freshwater pools, lakes, slow-flowing rivers¹, marshes, swamps and bogs², showing a preference for habitats with abundant emergent vegetation² and reedbeds⁴ in taiga (coniferous forest) zones^{2, 4}, birch forest zones⁴ and shrub/forest tundra² (generally avoiding open tundra)^{1, 4}. Non-breeders may also be found in flocks² along sheltered coasts¹ on estuaries, lagoons and shallow bays during this season⁶. Non-breeding On migration the species frequents lakes, estuaries and sheltered coasts². It traditionally winters on freshwater lakes and marshes², floodlands⁶, brackish lagoons and coastal bays² although low-lying coastal agricultural land¹ and wet pastures⁶ are now used increasingly². Diet The species is predominantly herbivorous¹, its diet consisting of the leaves, stems and roots⁴ of aquatic plants (e.g. algae and Zostera, Ruppia and Potamogeton spp.), grasses¹, sedges and horsetails (Equisetum spp.)². During the winter the species also takes agricultural grain, vegetables (e.g. potatoes and turnips⁴) and acorns¹, and on the breeding grounds young birds often take adult and larval insects⁴ (e.g. emerging chironomids)². Adults may also supplement their diet with marine and freshwater mussels². Breeding site The nest is a large mound of plant matter¹ built on dry ground or in reedbeds⁴ on small islands in or along the edges of lakes, pools or rivers³. The same nest mound may be used over several years although it is often repaired and new material is added². Management information A study carried out at a wintering site in Denmark found that large wind turbines (towers 68 m high with blades 66 m in diameter, blades sweeping the heights of 35-101 m) pose less of a collision risk to the species than wind turbines of a medium height (towers 45 m high with blades 48 m in diameter, blades sweeping the heights of 21-69 m)¹².

Systems:

Terrestrial; Freshwater

Threats [top]

Major Threat(s):	The species is threatened by habitat degradation and loss (such as the reclamation of coastal and inland wetlands)² especially in the Asian part of its breeding range¹. Threats to its habitats include agricultural expansion², wetland drainage for irrigation^{2, 13}, overgrazing by livestock (e.g. sheep)^{2, 13}, vegetation cutting for winter livestock feed¹³, the development of roads^{2, 13}, mining¹³ (e.g. strip mining of sediment)¹⁰, hydroelectric dam construction, disturbance from tourism¹³ and chronic oil pollution from oil exploration⁸, exploitation¹³ and transportation⁸. The species may suffer heavy losses from future oil spills⁸, flying accidents² (such as collisions with overhead lines² or wind turbines¹²), poisoning² from lead shot ingestion¹¹ and natural disasters such as droughts or heavy snowstorms¹³, and is susceptible to avian influenza, so may be threatened by future outbreaks of the disease⁷. The species is also threatened by hunting^{1, 2, 13}, nest destruction and by subsistence egg collecting^{8, 9, 13}.

Major Threat(s):

The species is threatened by habitat degradation and loss (such as the reclamation of coastal and inland wetlands)² especially in the Asian part of its breeding range¹. Threats to its habitats include agricultural expansion², wetland drainage for irrigation^{2, 13}, overgrazing by livestock (e.g. sheep)^{2, 13}, vegetation cutting for winter livestock feed¹³, the development of roads^{2, 13}, mining¹³ (e.g. strip mining of sediment)¹⁰, hydroelectric dam construction, disturbance from tourism¹³ and chronic oil pollution from oil exploration⁸, exploitation¹³ and transportation⁸. The species may suffer heavy losses from future oil spills⁸, flying accidents² (such as collisions with overhead lines² or wind turbines¹²), poisoning² from lead shot ingestion¹¹ and natural disasters such as droughts or heavy snowstorms¹³, and is susceptible to avian influenza, so may be threatened by future outbreaks of the disease⁷. The species is also threatened by hunting^{1, 2, 13}, nest destruction and by subsistence egg collecting^{8, 9, 13}.

Citation:	BirdLife International 2009. Cygnus cygnus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 24 May 2012.
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