Tern breeding colonies face welfare threats from both avian predators and human disturbance, with predator management programs raising their own welfare considerations requiring careful balancing.
Tern chicks killed by mammalian predators at breeding colonies suffer individual welfare harm that can extend to colony-level reproductive failure across thousands of nesting pairs. Predator management programs that use lethal control impose welfare costs on the removed predator animals. The welfare calculus of tern colony protection involves balancing the prevention of large-scale tern suffering against the welfare of smaller numbers of managed predators. Non-lethal options including electric fencing provide effective colony protection without predator welfare costs wherever applicable.