Capercaillie, Scotland's largest bird, faces extinction in the UK from disturbance, predation, and habitat loss requiring urgent intervention.
Capercaillie disturbed from winter roosting areas experience energy-costly flight responses that deplete fat reserves needed to survive winter. Repeated disturbance during lekking prevents successful mating. Individual birds stressed by chronic disturbance have reduced survival and reproductive success. Conservation at the population level requires welfare protection at the individual level through disturbance reduction.