Tern colonies on UK beaches and islands face threats from human disturbance, predation, and climate change that create significant welfare consequences for individual breeding birds.
Tern colony welfare depends critically on protection from disturbance during the breeding season. When a colony flushes from nests due to human approach or dog intrusion, eggs and small chicks are exposed to temperature extremes that can cause death within minutes in hot weather or hypothermia in cool conditions. Repeated disturbance also prevents parents from adequately provisioning chicks, leading to starvation. The voluntary wardening of tern colonies by dedicated volunteers, who prevent disturbance and manage predator access, directly saves chick lives and prevents adult stress across the entire breeding season.