- Lifespan
- 15–20 years in the wild, occasionally longer in captivity
- Size & Weight
- 145–160 cm long, wingspan 205–235 cm; 7–10 kg
- Habitat
- Winters on lakes, reservoirs, rivers and coastal waters; breeds on subarctic tundra and boreal wetlands in Iceland and Russia.
- UK Distribution
- Winter visitor (September to April) throughout the UK, with largest concentrations in Scotland, Northern England, and Ireland. Rare breeder, with occasional nesting in northern Scotland.
- Diet
- Entirely herbivorous, feeding on submerged aquatic vegetation, pondweeds, and algae; also grazes on grass and crops.
- Predators
- Golden eagles, white-tailed eagles, and foxes prey on eggs and cygnets; adult swans rarely preyed upon due to their size and strength.
- Mating Season
- April to July
- Breeding
- Clutch size 3–5 eggs, incubation period 35–40 days, typically one brood per season. Cygnets fledge at 12–15 weeks.
- Behaviour
- Highly vocal birds, producing loud bugling calls used for communication and territorial defence. Highly social in winter, often forming large flocks on favoured lakes. Pairs bond for life and return to the same breeding and wintering sites annually.