Northern gannets are one of Britain's most spectacular seabirds, with complex colonial social lives and welfare challenges from entanglement, food scarcity, and changing marine conditions.
Gannet welfare is shaped profoundly by the demands of their spectacular diving lifestyle and colonial breeding strategy. Individual welfare challenges include the physical risks of high-speed diving - injuries from hitting floating debris or underwater structures - and entanglement in plastic waste that gannets collect as nesting material. Plastic loops and fibres used as nest lining entangle chicks and adults, causing limb loss, infection, and starvation. Food availability is an increasing welfare concern: sandeels, which comprise the bulk of the gannet diet during breeding, have declined due to warming seas displacing their preferred prey and fishing pressure. Parents forced to travel farther for food return to chicks less frequently, causing starvation stress in growing chicks. Colony social dynamics include intense neighbour aggression - gannets within pecking distance of adjacent nests engage in frequent ritualised and genuine fights over space. Yet pair bonds are strong and long-lasting, with elaborate greeting rituals indicating recognition of individual partners. Colony welfare assessments now monitor fledging success, chick weight, and adult return rates as indicators of ecosystem health.