- Lifespan
- 25–30 years in the wild; oldest ringed bird recorded at over 34 years
- Size & Weight
- 55–67 cm, wingspan 130–160 cm; 910–1600 g
- Habitat
- Coastal areas including cliffs, beaches, estuaries, and increasingly urban environments such as rooftops and harbours.
- UK Distribution
- Found throughout the UK coastline and inland waterways; primarily a resident species with some winter immigration from continental Europe. Numbers increase significantly in winter.
- Diet
- Omnivorous and opportunistic; feeds on fish (especially sand eels, sprats, and cod), crustaceans, molluscs, insects, bird eggs, chicks, scraps, and household waste.
- Prey
- Fish (sand eels, sprats, cod), crustaceans, molluscs, bird eggs, chicks, and terrestrial invertebrates
- Predators
- Adults have few natural predators; eggs and chicks vulnerable to foxes, rats, corvids, and other large gulls. Great Black-backed Gulls occasionally prey on adults.
- Mating Season
- March to August; peak breeding April to July
- Breeding
- Clutch of 2–3 eggs (occasionally 1–4); incubation period 24–31 days; typically single brood per season. Chicks fledge at 6–7 weeks.
- Behaviour
- Highly social and gregarious, especially outside breeding season. Intelligent and adaptable, with strong site and mate fidelity. Known for aggressive, bold behaviour at colonies and when defending food sources; increasingly dominates urban areas.