Ospreys have successfully recolonised the UK and now support a growing population across England, Scotland, and Wales, with welfare linked to nest site fidelity and fish availability.
Osprey welfare at nest sites depends on access to clean, fish-rich water within practical foraging distance. Pairs returning from migration to find their nest occupied by other ospreys or damaged by winter storms face energetic costs of territorial conflict and re-establishment. Fish population declines in lakes and rivers used for foraging reduce breeding success. Disturbance at nest sites by photographers causes stress, particularly during incubation. The strong nest fidelity of ospreys means protection of established nest sites directly translates to reduced individual welfare costs.