Merlins are the UK's smallest falcon and have declined significantly in upland areas, with persecution, habitat loss, and prey depletion all affecting welfare.
Merlins face welfare threats from illegal persecution through poisoning and trapping on managed grouse estates. Poisoned merlins die from acute toxic effects. Those trapped die from injury or stress. Habitat degradation that reduces meadow pipit prey availability causes chronic nutritional stress during breeding. The small population size means each individual has high conservation value, making welfare protection of individual birds ecologically significant.