- Lifespan
- 12–15 years in the wild
- Size & Weight
- 42–51 cm, wingspan 67–83 cm; 340–1,000 g (females lighter than males)
- Habitat
- Freshwater and coastal waters including lakes, reservoirs, estuaries, and sheltered bays, preferring deeper open water.
- UK Distribution
- Winter visitor to the UK, arriving from September to April. Concentrated on larger reservoirs, estuaries, and coastal waters, particularly in Scotland, northern England, and Ireland. Rare breeding records.
- Diet
- Primarily aquatic invertebrates and molluscs, obtained by diving; also eats aquatic plants and seeds when invertebrates are scarce.
- Prey
- Freshwater mussels, snails, amphipods, chironomid larvae, and other benthic invertebrates
- Predators
- White-tailed eagles, marsh harriers, pike (for ducklings), and occasionally foxes and corvids
- Mating Season
- April to June (in northern breeding grounds)
- Breeding
- Clutch of 6–9 eggs, incubation period 24–28 days, single brood per season. Females are solitary nesters.
- Behaviour
- Highly gregarious in winter, often forming large rafts on water; males perform elaborate courtship displays with head-throws and calls. Excellent divers, capable of reaching depths of 3–6 metres. Relatively silent compared to other dabbling ducks.