Secondary Poisoning of Wildlife: Rodenticide Risks

Rodenticides used to control rats and mice poison raptors, owls, foxes, and other predators that eat poisoned prey. Reducing secondary poisoning protects wildlife welfare.

Key Facts

Second-generation anticoagulant rodenticides are found in the livers of over 80 percent of tested barn owls
Raptors that consume multiple poisoned rodents accumulate rodenticide to lethal levels
Secondary poisoning causes internal bleeding that may take days to cause death
Barn owl populations have declined significantly in areas with high rodenticide use
Alternative rodent control methods including habitat management and physical barriers can reduce rodenticide need

Welfare Considerations

Secondary rodenticide poisoning kills raptors, owls, and other wildlife through a slow and painful process. Animals that consume multiple rodents carrying anticoagulant rodenticides accumulate the toxin until they develop internal hemorrhaging. Death can take days, during which the animal experiences weakness, disorientation, and the physiological distress of internal bleeding. Barn owls, red kites, buzzards, foxes, and polecats are all commonly affected. The tragedy is that these predators are natural rodent controllers — their deaths create ecological vacuums that may increase rodent pressure. Integrated pest management approaches that use rodenticides as a last resort, in secured bait stations, with monitoring, can reduce secondary poisoning.

What You Can Do

Use rodenticide alternatives including physical traps and habitat management as first options
If using rodenticides, use only in tamper-resistant bait stations to prevent non-target access
Support retailer campaigns to restrict sale of second-generation anticoagulant rodenticides
Report dead or dying raptors to wildlife conservation groups for testing