Barn owls are facing secondary poisoning from rodenticides used in agricultural and urban settings, threatening populations across North America and Europe.
Barn owls accumulating sublethal doses of anticoagulant rodenticides may experience internal hemorrhaging that impairs flight, vision, and hunting ability before death. Death from rodenticide toxicity involves progressive internal bleeding over days before the animal succumbs. The ecological irony is profound: these natural rodent controllers are being poisoned by the very pest management they naturally provide. Secondary poisoning also affects red-tailed hawks, eagles, and other predators that consume rodents.