The avocet became extinct as a UK breeding bird during the 19th century and returned naturally to East Anglia in 1947, becoming the symbol of RSPB and a conservation success story.
Avocets nesting on islands require adequate water levels to prevent terrestrial predator access. Flood events that inundate nests cause egg and chick loss. Disturbance by recreational water users causes abandonment of exposed chicks. The careful water level management by reserve wardens directly determines breeding success for individual pairs.