Little terns are Britain's smallest seabird, nesting on beaches and shingle bars with very low populations that are acutely vulnerable to storm overwash, predation, and human disturbance.
Little tern welfare is precarious given their tiny population and concentrated nesting sites. Storm events that overwash nesting colonies during incubation cause total nest failure, with adults forced to abandon drowned or chilled eggs. Repeated nest failure causes physiological stress and depletes the breeding season energy budget. Predation by foxes - which learn to target wardened colonies at night when protection is reduced - causes direct mortality of chicks and adults. Human disturbance through dog-walking and vehicle driving on nesting beaches flushes birds repeatedly, causing thermoregulation failure in eggs and chicks. Wardening during the breeding season is the most critical welfare intervention.