Barn owls are iconic predators of agricultural landscapes, but they face severe threats from secondary rodenticide poisoning and habitat loss that cause significant welfare harm to individual birds and population-level declines.
Rodenticide poisoning causes one of the most protracted and painful wildlife welfare harms. Anticoagulant rodenticides prevent blood clotting by inhibiting Vitamin K metabolism. Affected barn owls hemorrhage internally over days to weeks, experiencing weakness, disorientation, and inability to hunt before death. Many poisoned owls are found alive but mortally ill - in extremis from blood loss with no effective field treatment possible. The widespread nature of contamination - affecting the majority of tested individuals - suggests that chronic sub-lethal poisoning is impairing the hunting and survival of many birds not yet showing overt illness. This population-wide welfare impact from a diffuse, persistent environmental contaminant represents one of the most challenging problems in wildlife welfare management.