# Swan — Facts, Threats & Conservation

*Cygnus*

> A swan is a large, long-necked waterbird of the genus Cygnus and the biggest member of the duck and goose family. There are six living species worldwide. Swans feed mainly on aquatic plants, form strong, often lifelong pair bonds, and are renowned for their graceful appearance.

**IUCN status:** Most species Least Concern (IUCN)  ·  **WARN range:** Europe, Asia, North America, South America, Australia

## Quick facts
| Fact | Value |
| --- | --- |
| Common name | Swan |
| Genus | Cygnus |
| Living species | 6 |
| Largest species | Trumpeter and mute swans |
| Length (mute swan) | About 1.4–1.6 m |
| Weight | Up to ~15 kg in large birds |
| Wingspan | Can exceed 3 m |
| Diet | Mainly aquatic plants (herbivorous) |
| Young called | Cygnet |
| Distribution | Europe, Asia, the Americas, Australia |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Aves
- **Order:** Anseriformes
- **Family:** Anatidae
- **Subfamily:** Anserinae
- **Genus:** Cygnus

## Conservation status
- **Status:** No single status applies to the genus. The widespread species, including the mute, whooper, black, trumpeter, tundra and black-necked swans, are all assessed by the IUCN as Least Concern, with several showing stable or increasing populations. Localised threats such as wetland drainage, pollution, collisions with power lines and lead poisoning still affect some populations even where the species overall is secure.
- **Population:** Not assessed as a single genus; individual species range from tens of thousands to several hundred thousand mature individuals
- **Trend:** Stable to increasing for most species
- **Assessed:** Most recent IUCN assessments
- **CITES:** Not generally listed on the CITES appendices
- Because the common swan species are not threatened, swans are often a conservation success story; the main concern is protecting the wetlands they and many other waterbirds depend on.

## Key facts: Swan
- Swans (genus Cygnus) are the largest waterfowl and among the heaviest flying birds, with the trumpeter and mute swans the biggest species.
- There are six living species, ranging from the all-white northern swans to the black swan of Australia and the South American black-necked swan.
- They are largely herbivorous, feeding on aquatic vegetation reached by dipping or upending their long necks.
- Swans usually pair for life, and both parents help raise their grey cygnets, which can stay with the family for months.
- In the UK, unmarked mute swans on open water are traditionally Crown property, a custom dating back centuries.
- The common species are assessed as Least Concern, but wetland drainage, pollution and disturbance still threaten swans and other waterbirds.

## What does a swan look like, and how big do they get?
Swans are unmistakable: very large waterbirds with long, slender necks, broad webbed feet and heavy bodies. The northern species, the mute, whooper, trumpeter and tundra swans, are white as adults, while the Australian black swan is sooty-black with a red bill, and the South American black-necked swan has a white body and a dark neck. Size is part of what sets swans apart from their goose and duck relatives. The mute swan typically measures around 1.4 to 1.6 metres in length, with large males reaching well over 1.5 metres and occasionally weighing more than 15 kilograms, while wingspans can exceed three metres. The trumpeter swan of North America is generally considered the largest waterfowl species, although heavy male mute swans rival it in mass. Young swans, called cygnets, hatch covered in greyish-brown down and only gradually acquire adult plumage over their first year, which is why a flock often shows a mix of pristine white birds and mottled grey juveniles.

## What do swans eat and how do they live?
Swans are almost entirely herbivorous. They feed mainly on aquatic plants, taking the roots, tubers, stems and leaves of submerged and floating vegetation, and will also graze on grasses and crops in fields near water. Their long necks are a feeding adaptation, letting them reach plants on the bottom of lakes, ponds and slow rivers by dipping the head under or upending the body so the tail points skyward. They may also eat small quantities of aquatic insects and other tiny animals, particularly as growing cygnets need protein. Swans are strong fliers despite their bulk, and northern species such as the whooper and tundra swan are long-distance migrants, travelling between breeding grounds and milder wintering wetlands. On the ground and water they can be surprisingly assertive, defending nests and young vigorously. Outside the breeding season many swans gather in flocks on lakes, estuaries and reservoirs, sometimes numbering in the hundreds where food is plentiful.

## Do swans really mate for life?
Swans are famous for their devotion, and the reputation is largely deserved. Pairs usually form strong, long-lasting bonds and often stay together for life, returning to the same territory year after year to breed. Both the male, called a cob, and the female, called a pen, share in raising the family: they build a large nest of vegetation near or over water, take turns incubating the eggs, and then guard and guide the cygnets together for months after hatching. This long period of parental care gives young swans a strong start. Pair bonds are not absolutely unbreakable, and separations do occur, more often after a failed breeding attempt, but lifelong fidelity is the norm rather than the exception. The image of two swans facing each other with their necks forming a heart shape has become a widespread symbol of loyalty and love, rooted in genuine, observable behaviour rather than pure myth.

## Why are swans linked to the British Crown?
In Britain, the mute swan carries a centuries-old royal tradition. By long-standing custom, the reigning monarch holds the right to ownership of all unmarked mute swans swimming in open water, a status that earned the swan the nickname 'Royal Bird'. In practice this right is now exercised only along certain stretches of the River Thames and its tributaries, where the Crown shares ownership with two ancient livery companies, the Vintners and the Dyers, who were granted rights to keep swans in the fifteenth century. Each year a ceremonial count and health-check of swans on the Thames, known as Swan Upping, takes place, during which young birds are weighed, measured and assessed before being released. It is worth correcting a common myth: the monarch does not own every swan in the country, only unmarked mute swans on certain open waters. Elsewhere, swans are wild birds protected under ordinary wildlife law.

## Swan vs goose: how to tell them apart
| Feature | Swan | Goose |
| --- | --- | --- |
| Size | Largest waterfowl; very heavy | Smaller and lighter |
| Neck | Very long, often curved | Shorter, held straighter |
| Main diet | Mostly aquatic plants | More grazing on land |
| Feeding style | Dips or upends to reach underwater plants | Often grazes grass on shore |
| Pair bonds | Often lifelong | Long-lasting but more variable |

## What WARN does
WARN does not run field projects dedicated specifically to swans, which are mostly common and live well beyond our five partner countries; instead this guide is part of our free public education work. The wetland loss, pollution and disturbance that affect swans are the same pressures bearing down on many waterbirds and other species we do help protect, so understanding one connects to caring for all.

If this guide deepened your wonder at the natural world, supporting WARN's free education and animal-welfare work helps us keep telling these stories.

## Frequently asked questions: Swan
### How many species of swan are there?
There are six living species of swan in the genus Cygnus: the mute swan, whooper swan, tundra swan and trumpeter swan of the Northern Hemisphere, the black swan of Australia, and the black-necked swan of South America. They share the family with ducks and geese but are the largest members. Several extinct swan species are also known from the fossil record.

### What is a baby swan called?
A baby swan is called a cygnet. Cygnets hatch covered in soft greyish-brown down and follow their parents on the water within a day or two. They gradually grow adult feathers over their first year, so young white-species swans look dusky grey before turning white. Both parents guard and feed the cygnets, which often stay with the family for several months.

### Do swans mate for life?
Swans usually form strong, long-lasting pair bonds and often stay together for life, returning to the same breeding territory each year. Both parents share nest-building, incubation and raising the cygnets. Bonds are not unbreakable, and separations do happen, more often after a failed breeding season, but lifelong fidelity is genuinely the norm, which is why swans have become a lasting symbol of devotion.

### Does the Queen or King own all swans in the UK?
No, this is a common misconception. By tradition the British monarch can claim ownership of unmarked mute swans on certain stretches of open water, chiefly parts of the River Thames, where the Crown shares the right with two ancient livery companies. The annual Swan Upping ceremony counts and checks these birds. Most swans in Britain are simply wild birds protected by ordinary wildlife law.

### Are swans dangerous or aggressive?
Swans are generally peaceful but can be assertive, especially when defending a nest, eggs or cygnets. A threatened swan may hiss, raise its wings and lunge, and large birds can deliver a strong blow with their wings. Serious injuries to people are rare, and most aggression is a bluff to drive intruders away. Giving nesting swans space during spring and summer keeps both birds and people safe.

### What is the difference between a swan and a goose?
Swans and geese are closely related waterfowl, but swans are larger, with much longer necks and heavier bodies, and are the biggest members of the duck, goose and swan family. Geese have shorter necks and proportionally longer legs, and graze more on land. Swans feed mainly on aquatic plants reached by dipping their long necks underwater, and tend to form longer-lasting pair bonds.

## Sources
- [Swan — Wikipedia](https://en.wikipedia.org/wiki/Swan)
- [Mute swan — Wikipedia](https://en.wikipedia.org/wiki/Mute_swan)
- [Trumpeter swan — Wikipedia](https://en.wikipedia.org/wiki/Trumpeter_swan)
- [Swan — Encyclopaedia Britannica](https://www.britannica.com/animal/swan)
- [IUCN Red List](https://www.iucnredlist.org/)
- [Cygnus olor — IUCN Red List](https://www.iucnredlist.org/species/22679839/85946855)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/swan