Barn owls are iconic farmland birds that provide natural rodent control but are being poisoned in large numbers by rodenticides used in agricultural and domestic settings, causing a significant and largely invisible welfare crisis.
Barn owl welfare is compromised by the slow, painful death caused by anticoagulant rodenticides. Owls consuming poisoned rodents accumulate sub-lethal doses that impair blood clotting — affected birds experience internal bleeding, weakness, and a drawn-out death. Because owls consume multiple rodents daily, bioaccumulation is rapid. Surviving owls with sub-lethal exposure show impaired flight, coordination problems, and reduced hunting success. Habitat loss removes the rough grassland margins that support the vole populations barn owls depend on, forcing longer foraging flights. Cold snap starvation events kill significant numbers when snow prevents ground hunting. These cumulative pressures on a species with delayed reproduction — one to two clutches per year — make population recovery slow when mortality increases.