Barn Owl Population and Rodenticide Harm

Barn owls are suffering secondary poisoning from rodenticides used in agricultural and domestic settings, threatening a population already at the edge of viability in the UK.

Key Facts

UK barn owl population recovered to around 4,000 pairs — still vulnerable
Second-generation anticoagulant rodenticides (SGARs) accumulate in owl livers
Studies find SGARs in over 80% of barn owls examined post-mortem in the UK
SGARs remain in the environment for months and concentrate up the food chain
Alternatives including trapping and first-generation rodenticides pose lower owl risk

Welfare Considerations

Barn owls poisoned by SGARs die from internal haemorrhage, often slowly and after apparent recovery from sub-lethal doses. The scale of exposure — 80%+ of tested owls carrying SGARs — indicates near-universal population contamination. Individual owls may be debilitated by sub-lethal exposure, with impaired hunting ability, before eventually dying from accumulated dose. Given the availability of safer rodent control options, widespread SGAR use represents avoidable harm to an iconic species.

What You Can Do

Never use second-generation rodenticides outdoors or in open buildings
Use snap traps, electronic traps, or first-generation rodenticides as safer alternatives
Install barn owl nest boxes to support the population and monitor health
Support the Campaign for Responsible Rodenticide Use (CRRU)
Report dead barn owls for testing through the Barn Owl Trust monitoring programme