If you find you have a rat problem, you may be tempted to either contract with a pest service or purchase those black bait boxes at a farm supply store. However, here is the story on that bait box and its dangers to our local population of rat predators, meaning the owls, hawks and eagles we have in our area.
The most common poison for rats these days is bromadiolone. I queried the Ai program, Perplexity about the dangers of bromadiolone to predators. Here’s its answer.
Even at a mix rate of 0.005% per 1 oz. block, it poses a significant danger to owls that eat rats poisoned by it. Bromadiolone is a second-generation anticoagulant rodenticide (SGAR), which is known for its high risk of secondary poisoning—when a predator like an owl consumes prey that has ingested the poison.
Key points:
• Bromadiolone is classified as a moderate to high secondary poisoning risk for birds, including owls.
• Residues of bromadiolone can persist in rodent carcasses for over 100 days, meaning poisoned rats can remain toxic to predators long after death.
• Owls and other birds of prey have been found with bromadiolone residues in their livers, and studies show widespread contamination among wild owl populations.
• Owls are particularly vulnerable because they have a limited ability to detoxify anticoagulant rodenticides, making them more susceptible to poisoning than some other birds or mammals.
• Even sub-lethal doses may impact owl health and survival, especially during periods of stress or food scarcity, though the exact effects of low-level, chronic exposure are not fully understood.
In summary: Using bromadiolone as a rodenticide creates a real risk of harming owls and other predatory wildlife through secondary poisoning, regardless of the specific concentration in bait blocks. Safer alternatives or non-chemical rodent control methods are recommended to protect owls and other non-target species.
Filed under: environmental education, Olympic Peninsula |
THank you for this information. I have been occasionally using this ingredient in rat traps as I was told by a “natural, no-harm” pest company that this ingredient wasn’t a secondary kill product. I’ll stop using it but now I have to figure out how to safely dispose of the blocks.