Arctic terns migrate from Arctic breeding grounds to Antarctica and back each year -- the longest annual migration of any animal. Understanding their welfare across this extraordinary journey informs conservation priorities.
Arctic tern welfare during the breeding season is extremely vulnerable to disturbance. Colonies on beaches where access is unrestricted lose most nests to disturbance events. A single walk through a colony causes adults to leave nests, exposing eggs to chilling or overheating and chicks to predation. The breeding period is brief -- disturbance at the wrong moment causes irreversible failure of that year breeding attempt. The long migration that follows requires good body condition built during successful breeding. Protecting breeding colonies from disturbance is the highest-welfare intervention available for this species.